Photo: Russian Olive. © 2020 Delena Norris-Tull
Minutes of the 7th Annual Western Weed Control Conference, Boise, Idaho, June 6-7, 1945
Slade Franklin, Wyoming Department of Agriculture Weed and Pest Coordinator, loaned these archival minutes to Dr. Delena Norris-Tull. The original minutes were typed up documents from the 1940s. Dr. Norris-Tull transcribed and summarized the minutes, and added commentary throughout.
84 individuals attended this conference, many more than in years past. Representatives from various county and state agencies, scientists from various universities, and representatives of several chemical industries attended. No landowners (farmers or ranchers) seemed to appear on the list of guests. Only a few representatives from federal agencies attended: the Boise representative from the Bureau of Reclamation, and the US Forest Service agent from Ogden, Utah, and the US Indian Service Extension Supervisor from Salt Lake City. One international guest attended, Enrique Summers, from Peru.
The following states sent representatives to the conference:
No representatives from Arizona or New Mexico were present.
Report of the Treasurer: Balance on hand: $467.10
Summary of the Wednesday sessions:
The Governor of Idaho welcomed the conference attendees and recommended that the representatives of the various agencies, “I hope that you men here from the different states will agree and try to interest the federal government, not only in support of an eradication program, but in financial support... The federal government owns much of this land. I think the federal government should be solicited to support this program. Out of this war will undoubtedly come some materials that will be more effective than any we have had up to date…”
Mr. Walter S. Ball, Chief of the California Department of Agriculture, Bureau of Rodent and Weed Control and Seed Inspection, gave a report regarding the development of the North Central States Weed Control Conference. This conference was called to organize 13 of the North Central states for the purpose of closer coordination and cooperation, very similar to the Western Weed Control Conference. Mr. Ball was asked to meet with the group to assist them in organizing, and he reported that their organization is set up in a similar manner, and for a similar purpose, as the Western Conference. Nearly 100 agency researchers and regulatory representatives, including several representatives from federal agencies, attended the conference. This is only the second region-wide weed control organization that has come into existence, with the Western Weed Control Conference being the first. That now brings 24 states into a coordinated effort at weed control.
In opening comments by Mr. C.H. Schrader, Department of Agriculture for Minnesota, he pointed out that, “If the weed losses in the United States estimated by the US Chamber of Commerce were $3 billion in 1930, we can easily suspect that they are now near $5 billion, or an average of more than $100 million per state…”
Mr. Ball described a speech by the representative of the US Department of Agriculture, Dr. M.A. McCall, in which he pointed out that while this conference focused on control of bindweed, at least 30 plants can now be considered noxious weeds. Dr. McCall mentioned Johnson grass, Russian knapweed, white top, and poverty weed, and stated that, “More than 2,000,000 acres of good agricultural land (are) virtually out of production because of noxious weeds... The Bureau of Reclamation spends more than $100,000 a year dragging weeds out of irrigation canals and drainage ditches...” He also mentioned that there are about 39 species of shrubs and trees now infesting some 10,000 acres of good pasture or rangeland.
Mr. Ball pointed out that a number of researchers attended, and gave reports, at the conference. The conference attendees pointed out the value of the research projects, and the networking opportunities for the researchers themselves.
He described a report by Mr. F.L. Timmons, the Chairman of the Research Committee, who listed the following areas needed for immediate research: “the development of a cropping system and rotation for the control of annual weeds; development of inexpensive methods of weed control on low valued lands; development of methods for the control of erosion during the eradication of perennials; the improvement of tillage machinery; the continuous testing of herbicides to determine their relative effectiveness…; the improvement of machinery for the application of dry material;… research on the occurrence of weed seeds in crop seeds and in feed grains;… the improvement of machinery for cleaning crop seeds.”
Mr. Ball quoted a report from Mr. L.W. Kephart: “One of the brighter aspects in the post-war weed picture is the probability that new chemical weed killers will be available of a variety and potency which we have not heretofore known… Weed eradication, as a science, has always lagged far behind other kinds of pest control in the development of technical aids, and our knowledge of the nature and utilization of herbicides is crude indeed by comparison with the highly intricate knowledge of insecticides, fungicides, germicides, and the like... (In the past 50 years) scarcely a dozen men have had the opportunity to give their full time and thought to the possibilities of chemicals in the control of weeds. As a result, the science of chemical weed control is still elementary and farmers have had available for their use, at least until very recently, only such unimaginative materials as arsenic, chlorate, sulfuric acid, and petroleum oil.” Mr. Ball reported that, “Some of the materials Mr. Kephart mentioned which will be in the field for further research are the sulfur compounds, the acetic acids, the aldehydes, organic peroxides, formates, oximes, chlorinated hydrocarbons, chlorinated phenols, and the dinitro compounds.”
Mr. Ball summarized several reports on weed control, as follows:
Nebraska: “Crop losses in past years due to (bindweed) have been millions of dollars… In 1943… the estimated loss exceeds $1,960,000. This estimate was made on the basis that this weed reduced corn yields 40%, wheat twenty 25%, oats 35%, barley 40%, and alfalfa and rye each 20%.”
Kansas: “from 1939 to 1943 inclusive,… bindweed has been eradicated on an average rate of about 10,000 acres per year… by cultivation... The total of bindweed eradicated, including cultivation, the use of sodium chlorate, and by special methods, was 53,390 acres.”
“Of the many reports which were given (by states)… practically all of the successful programs with those under district organization, such as the Nebraska program where weed eradication districts are set up as subdivisions of the state. In some states, however, this type of organization is set up by counties.”
“Another program was carried out by Dr. L.M. Stahler, who initiated statewide tests where only two herbicides other than sodium chlorate showed any promise in Minnesota, these being a ammonium sulphamate and Borax. One of the interesting points in his results was that 1 pound of chlorate was equal to 5 pounds of Borax in effectiveness on the control of bindweed… He found, however, that there was a wide variation in the efficiency of either Borax or chlorate alone and that recommendations of the rates of applying any of these should be made with care. I mention this work primarily because, other than the extensive use made of Borax in California, the work done originally by Mr. R.N. Raynor, there has not been intensive research carried on in so wide a scope as this in Minnesota.”
Mr. Ball summarized a report by Mr. A.K. Hepperly, Agricultural Agent of the C.B. & Q. Railroad, who found that the railroads’ use of chlorate to eradicate weeds are “so erratic that it requires so much labor for the original application and the follow-up treatments, and that the seedling problem, together with the fire hazard of sodium chlorate, makes it fall far short of a solution to the railroads’ problem of weed eradication… Considerable Borax has been used on the railroad with good results… inspection during the summer of 1943 showed good kill at most locations, some of which were 100%. Inspection in 1944, however, showed that Borax can be as erratic as sodium chlorate.”
Mr. Ball also learned that, “it appeared that all the states had some type of laws and regulations but there were very few states that had the manpower and the facilities for the enforcement of such laws.”
Report by Mr. Alton S. Craft, UC Davis, on herbicidal properties of oils:
“Oils are used as general contact herbicides for pre-emergence spraying in vegetable crops and for general weed killing on fence lines, road sides, and other places where plant growth is undesirable. They are also used as selective sprays against weeds in such crops as carrots, celery, and other members of the carrot family. They are used as carriers for denitro compounds and other phenolic herbicides. Their latest use is as carriers for the hormone weed killer, used in the control and eradication of cattails, tules, and other weeds that are difficult to wet. Finally, they are used in many horticultural sprays designed to kill insects and fungi. There is a real need for information on the toxic properties of oils as well as on their function in the spread and penetration of other pesticides.
“There are several aspects to a consideration of oil toxicity. First, there are two types of toxicity, namely acute and chronic toxicity. Second, there is the question of dosage as it relates to the physical properties of wetting and spreading to the chemical factors of composition. Selectivity is a third aspect. As with other herbicides, selectivity of oils entails a quantitative relation between dosage and chemical composition. Finally, there is the problem of composition as related to physiological effect. This has been studied by comparing the toxic properties of many oil fractions, and by the use of pure compounds, insofar as these have been available.
“The rapid killing of contacted tissues by oils is termed acute toxicity. It is characterized by a discoloration of the tissues, from a live green to a dead green or gray, accompanied by death. It is always manifest within a few hours after spraying and reaches a maximum within two or three days.
“Chronic toxicity results in a slow yellowing of leaves, killing of the growing point tissues, particularly in grasses, deterioration, and finally death of the plant. Tissue suffering from chronic injuries seem particularly susceptible to infection by fungi and often death of the plant is secondary, resulting from invasion by such parasites.
“Chronic toxicity seldom appears short of a 48-hour period and in many instances shows up only after a week or more. It has never been observed after use of light fractions within the gasoline range. These compounds volatilize rapidly from the plant. Severe chronic toxicity inevitably follows spraying with heavy, unrefined or lightly treated, petroleum fractions. Some chronic toxicity results from treatment with highly refined fractions. The only heavy liquid hydrocarbon used that has not caused chronic injury as a pure sample of n-cetane.
(Delena’s commentary: The rest of the report gives details of dosages, and information on which plants are readily killed by various oils. The report contained no information on how long the oils remained in the soil, and no information on longer term toxicity to desired plants and animals).
A report was given by Mr. R.B. Balcom, from the U.S. Bureau of Reclamation, on “Control of Waterweeds in Irrigation Systems.” (This is the same individual who reported at the 1941 conference, thus some information is redundant with the 1941 report). Key points are listed here:
“Early irrigation in the United States was, for the most part, confined to diverting water directly from natural streams. When these carried sufficient silt, the growth of water plants was inhibited. When simple diversions were no longer adequate, it became necessary to build dams to impound the water supply. The reservoirs thus formed act as suppling bases basins and the water coming from them is comparatively clear.
”Because of this and perhaps other influencing factors, the control of waterweeds has become increasingly difficult in many irrigation systems…
”Waterweeds seriously reduce the efficiency of irrigation systems... Because of their desilting action, these (waterweed) growths build up silt bars in the channel which further reduce the canal capacity and necessitate costly dredging. Also, as the water cuts around the silt bars, extensive erosion of canal banks and beds often occurs. Weeds cause ditchbreaks by retarding the flow of water until it overflows the banks, which results in delays in service and repairs as well as damage to crops by flooding and the loss of water so vital to our irrigated areas. A large amount of water is lost each year to transpiration of cattails, tules, and other emergent plants.”
The report listed the following plants as waterweeds: The floating weeds cause the least problems: water lettuce (Pistia stratiotos), water hyachinth (Eichornia crassipes), floating duckweed (Lemna species), water velvet (Azolla species).
The emergent weeds are more prevalent in drains than in canals or laterals: cattails (Typha), tules (Scirpus), parrot feather (Myriophyllum prosepinacoides), water primrose (Justicia), water cress (Nasturtium).
The submerged weeds cause the greatest problems, as they are more widely distributed and occur in both ditches and drains: coontail or hornwort (Ceratophyllum demersum) is the most troublesome unattached weed; troublesome attached weeds include pondweeds (Potamogaton), horned pondweed (Zanachellia palustris), water milfoil (Myriophyllum), waterweed (Anacharis canadensis), water buttercup (Ranunculus), spiney naiad (Najas marina), yellow stargrass (Heterantherea dubia), and muskgrass (Chara), and algae (which may be floating or unattached and become tangled with rooted plants).
The report extensively described implementation of the control methods, mechanical, drying, and chemical. Shading has also been used in some locations. It also described the use of the following chemicals: sodium arsenite and other arsenicals, copper suphate, and more recently, Benoclor (a chlorinated benzene). The following information was provided about the new chemical Benoclor:
“Tests were first conducted to determine if crop plants would be injured when irrigated with Benoclor-treated water. It was found that several times the strength of the concentration used for controlling waterweeds was necessary before even a slight injury (to crops) was sustained. No ill effects have been reported where the chemical has been used extensively but precautions are being taken to prevent it from reaching crop land. Turnouts along the section of ditch being treated are closed while the chemical blanket is flowing past. Where possible the treated water is turned into a wasteway and where these are not available the turnouts for about a mile past the end of the treated area are closed…
“… with certain established procedures in the use of Benoclor, many irrigation districts have been able to control their waterweeds growths more efficiently then by their previous methods. It has been of particular value during the present labor shortage. Instead of a crew of possibly 25 workmen being necessary, as in chaining and hand methods, the waterweed growths in an entire irrigation system can be controlled with Benoclor by two men.”
A lengthy description follows, for the application techniques, and on more recent formulations for Benoclor.
Mr. Balcom ended his report with the following prediction: “It is quite possible that scientific research will bring forth an even more effective chemical, one which will follow down into the root system of the waterweeds and kill the entire plant, as do the new ‘hormones’ on land weeds. It will be interesting to see how 2,4-D will effect water plants.”
[Delena's commentary: It is notable that at this time, a number of native plants were considered noxious weeds by the US Bureau of Reclamation].
Next, a representative from the USDA Bureau of Plant Industry, Soils, & Agricultural Engineering, Dr. McCall, was introduced. He stated that few federal resources are presently available to tackle the weed problem. He expressed willingness to ask the US Forest Service and other federal departments to increase financial support for weed removal on federally controlled lands.
[Delena's commentary: It has been apparent from these minutes and conversations with various State Agency representatives that the Federal Government has lagged way behind the States in tackling the weed problems].
Next, Mr. Lee Burge, from the Nevada Department of Agriculture, reported on the rapid spread of Halogeton in Nevada. This weed is spreading more rapidly than previously thought, and is germinating extremely rapidly.
Mr. J.R. Douglas, an entomologist from the US Bureau of Entomology and Plant Quarantine, gave a report on research on the beet leafhopper (Eutettix tenellus). The weed Halogeton glomeratus is closely related to Russian thistle (Salsola kali var. tenuifolia), which is a summer host for the beet leafhopper. In 1943, cage tests were conducted to determine how rapidly beet leafhopper will reproduce on Halogeton. And field counts were conducted, in Nevada and Utah in 1943 and 1944, in locations where the two plants grow in close proximity. In the 1943 data, both weeds hosted a similar count of beet leafhopper. But in 1944, Russian thistle hosted significantly more of the insects. Both plants are also a summer host of curly top virus. The research pointed to concerns that, as Halegeton spreads its range, it will also potentially increase the range of the beet leafhopper and curly top virus. At this point, little is known of the ability of Halegeton to compete with or replace native flora. It is a non-native plant from the Mediterranean.
Mr. A.F. Bracken, Extension Agronomist from Utah, mentioned that it has become a serious weed in Utah, and is of concern due to high levels of oxalic acid, which are potentially toxic to sheep and cattle.
Mr. Burge said that the plant first became known in the US in 1935, and has now spread to Utah, Idaho, Nevada, and Wyoming. He commented that feeding tests have shown that it can kill sheep.
Mr. Victor P. Rasmussen, from the Utah Department of Agriculture, stated that they studied its spread in Utah and determined that the state lacks the financial resources to reduce its spread.
The members agreed to form a special committee to create a resolution to request federal aid to reduce the spread of Halegeton.
Mr. Thomas H. Van Meter, from the US Forest Service, stationed in Idaho, gave a report on “Noxious Weed Control on National Forests.” The report is summarized:
“For many years the forest service has been combating plants poisonous to livestock and has included this control in the range management program. During the last 10 years, an invasion of noxious plants not native to our forest lands has been noted; and in some cases, spreading at an alarming rate. This invasion has been on past depleted areas that have not regained their normal vegetative balance, and control measures have been inaugurated on many areas. We believe that proper stocking and range management will generally take care of any infestation over a period of years.
“Undesirable or noxious weeds on National Forests fall into slightly different classes than those on cultivated areas. These weeds,… are classified as:
1. plants poisonous to live stock;
2. invasion plants;
3. plants noxious to adjacent cultivated lands.
“The more common poisonous plants found on forest ranges in the western states are: Larkspur (Delphinium species), death camas (Zygadenus), lupines (Lupinus species), water hemlock (Cicuta), loco (Astragalus & Oxytropis species), black laurel (Kalmia), sneezeweed (Helenium).
“One or more of these plants are native to any of our range lands and present few problems under proper management. Heavy livestock losses are caused by improper seasonal use, excessive grazing, or improper distribution.
“Grubbing (i.e., physical removal of tree stumps) has been effective as a control measure in areas of concentration, but excessive costs have caused the discontinuance of this method on most forests.”
He described some chemical treatments, using Borax on lupines (to prevent sheep losses in Idaho), and chemicals and oil spray on black laurel in California, and a variety of methods have been used to eliminate larkspur and water hemlock in Oregon and Washington.
“Invasion species that have caused no or little concern on forest lands are primarily: goatweed (Hypericum perforatum, also known as Klamath weed or St. John’s wort), mule’s ears (Wyethis amplexicaulis), false hellebore (Veratrum californicum), Medusa-head (Elymus caput-medusae).”
He reported new concerns about the spread of goatweed in California, Idaho, and Montana. Some treatment with Borax has been conducted. But Borax causes concern because it is expensive, and it causes soil sterility for three years.
He reported that, while mules ears and false hellebore, both native species, are not widespread, on depleted ranges, they can establish solid stands that complete with desireable forage plants. A light oil spray applied during early growth stages has been effective at eliminating these plants.
He expressed some concerns about the recent spread of medusa-head in California. It is not a desireable forage, when compared with Bromus tectorum, and medusa-head also poses a greater fire risk. Medusa-head has the potential to become a serious problem on range lands.
[Delena's commentary: This is such an interesting report, considering that Bromus tectorum, previously known as Anisantha tectorum, is cheatgrass, and is now considered a major invasive species problem, that is already causing high risks for wildfires in the west!]
He also described work being conducted to control Canada thistle and whitetop.
“When combating weeds, we have used sodium and calcium chlorate, Borax, oil spray, grubbing, and various other means. All have deficiencies that make them impractical for the widespread use which is required if the problem is to be successfully met. In Montana alone, it has been reported that over 100,000 acres need treatment on National Forest land, and other states reports similar acreages, so any proposed method for large-scale use should be reasonable in price, easy to apply, and nominal in its damage to soils and other vegetation.
”To date the Forest Service has financed their program from the limited range improvement funds allotted, as no direct appropriations have been made for this type of work.”
Mr. Ball reported on research being conducted in cooperation with the US Bureau of Entomology and Plant Quarantine on two biological control insects. These insects have been effective in use in Australia. He stated, “These insects have been brought into California, after thoroughly investigating the possibilities of their detriment to other plants or crops. A complete series of starvation tests have been carried out to prove that they would not be destructive to other plants. They attack nothing but Hypericum (goatweed). We do not know anything as yet about the natural predators, which may prey upon these insects. If they are present, our hopes for control will be very limited. We are not hoping to use these insects on those areas, at least at the present time, where we can carry on our regular program with Borax and cultivation.”
Dr. A.S. Crafts, from the University of California-Davis, stated: “We are going to have to have research programs and find what to do about this condition (the spread of goatweed). We must cooperate and consider these new problems with research. We are going to have to use biological methods wherever possible and more facilities may be needed.”
Mr. V.A. Cox, Superintendent Ada County Weed Control (Idaho), asked, “Isn’t it a fact that where they did control with those insects, after they destroyed the weed, your insects were destroyed and then the same process is repeated over again?”
Mr. Ball: “We have recognized that fact, but if these insects can reduce the infestation on the heavily invested ranges, we feel they are worthwhile. We recognize that there is a seed problem and know that (goatweed) seed will live on the soil for a number of years. Our tests show that this weed will continue to germinate after 10 or 15 years.”
Mr. W.L. Hendrix, President, Idaho Noxious Weed Association: “Does it do any good to try and burn Klamath weed?”
Mr. Ball: “Yes, we have tried burning and we have had successful results, where adequate dry material was present to carry the fire.”
Mr. W.W. Robbins, from the University of California-Davis: “Where these burning experiments were to be carried out, we ran into one difficulty that as soon you open the ground the (weed) seedlings come up like hair on a duck’s back. But there are indications that where we can get grass to come back and we get dry material to carry the fire that we can get some thinning. These experiments, …have not been completed, however, so that we have no data at present.”
Summary of the Thursday sessions:
Mr. C.T. Seeley, from the Agronomy Division of the University of Idaho gave a report on the new developments with the use of hormones in weed control. He described the use of 2,4-D:
“It wasn’t until 1941 that Nevada thought you might be able to use it for weed control, and it wasn’t until 1944 that any actual work was done,… as far as weed killers was concerned. 2,4-D was picked primarily because it happened to be one that was easily manufactured and was available in large quantities... Since our work was done with cargowax carriers,.. our results with certain types of weeds was quite promising, particularly…because of cost. At that time, the price of 2,4-D was very reasonable. It since has risen... On many of the root perennials we got very good results… The results were outstanding on dandelions and some such plants. Some of the biennials in the second year of growth were outstanding. At the same time, on the root stock perennials, we got a peculiar reaction. We got vertical root kill but not lateral. In most cases we got recovery (i.e., weeds growing back)… From other weeds in that group we got practically no results at all, possibly due to application too late in the season… We have 150 tests out so far this spring, and what they look like at present is no indication at all as to what they will look like three months from now. We have not been able to get the carrier… We did run into difficulties. One is soil effect that is showing up in many places. In other places, it is causing practically no trouble at all. Another thing that some run up against is that most of the preparations get into trouble in hard water. In some cases, it is apparently due to antagonistic salts in the water. In some, calcium precipitates need investigation. Probably the most susceptible has been morning glory and Canada thistle. In the lawn work more or less, we are doing quite a lot of work with 2,4-D as a selective material, and it is better than anything we have had. Some of the grass species have been injured by 2,4-D applications at high concentration, as we get some stunting and some burning. Whether or not it is a permanent injury, we do not know… The cost at the present time is out of line… The temperatures are frequently too low... One of the things that is bothersome in some sections is that water is a major factor and it is very difficult to get… What the (water) limits are we don’t know as a number of things have come up relative to temperatures. Every one who has worked with it notices that nothing happens with low temperatures.”
Mr. W.A. Harvey, of the University of California-Davis, gave a report on the effects of 2,4-D on soil. A research study of differing concentrations of 2,4-D on crop growth showed that different crops differ in their susceptibility to the chemical. “Oats survive at much higher concentrations than peas or sunflowers, and sunflowers tolerate higher concentrations than peas. However, by using a high enough concentration, it is possible to prevent growth of any of these plants. This is definite evidence that 2,4-D does sterilize soil to some extent, the amount of sterilization depending on the amount of chemical in the soil.
”The three soils (tested) also differ in the amount of toxicity shown by the chemical. The Stockton adobe clay shows the least toxicity or, putting it another way, it takes more of the chemical to show toxicity in this soil than in the others. The Hanford fine sandy loam shows the highest toxicity, and the Yolo adobe clay chosen intermediate toxicity…
”Thus we see that serious effects on crops are possible with very small amounts of the chemical in the soil. Now we don’t know yet how long this effect lasts in the soil. Apparently it lasts for 30 days at least and is definitely reduced in 60 days, but we are long way from having final data on it…
“In another year, we hope to have some of the answers but right now there are a lot of things we don’t know about 2,4-D.”
Various individuals asked more questions about this preliminary research. Mr. Harvey added that they have not yet done research on the rate of penetration of 2,4-D in the soils.
Dr. Crafts added, “With our past experience with leaching of chemicals in the soil, we have come to recognize two types of behavior. Arsenic will be fixed by most soils. On the other hand if you take nitrate and chlorate it will be distributed throughout the soil. 2,4-D may compare more with Borax which fixes loosely. We have tested eight California soils.”
Mr. Jerome Evans, from the Idaho Agricultural Adjustment Agency (AAA), asked: “Has anyone here any observances as to the effect of the 2,4-D on the microflora of the soil?”
Mr. Seeley: “I can give you some secondhand information...The Information I have is that it has pretty bad effects as far as soil bacteria is concerned, but very little effect on fungi.”
Mr. Robbins: “The bacteriologist at our station applied 2,4-D to his lawn. Following the application, he applied ammonium sulfate and he made the remark that he got no response out of the ammonium sulfate for a very long time, and he was wondering if (2,4-D) had any effect on the bacteria in the soil… We need to know more about that. Doesn’t this work indicate to you people that we had better go a little bit slow on our application of hormones to agricultural soil?… In the light of your work, what advice would you give (to farmers) with respect to seeding with alfalfa a few weeks after the application of hormones?”
Answer: “Farmers should be advised to proceed cautiously until more is known of the effects of 2,4-D to soils.”
Another report was presented on the use of 2,4-D in the wetter conditions in the eastern states, where they have had success with planting crops 6 weeks after applying 2,4-D.
Mr. Harvey gave a lengthy report on the differential response of various weeds to 2,4-D. A number of the “weeds” that were described are native plant species. Several individuals expressed concerns about using 2,4-D before more is known about soil sterilization and other effects on the soil and crops. Concerns were raised about the need for research on the effects on animals. Mr. R.N. Raynor, from California, reported, “We don’t have any experience with large animals, but we have made tests on small animals and the tests indicate that large doses by mouth are not injurious and applications through the skin are not injurious.”
[Delena's commentary: the lack of research on animals is alarming, as different species would react differentially to the toxic chemical, just as would different species of plants.]
Finally, a few brief state reports were given.
Mr. Buford E. Kuhns, from the Idaho Extension Service: “…We have supplied each of our county agents…with a number of what we call an information sheet. We’re asking them to carry on a little experimental work with these various 2,4-D preparations, and we are asking them to prepare a short information sheet, showing the location, date of application, type of soil, temperature, and all of the other factors that might be of interest, and give their notes on their observations... We will then assemble all that material and hope that we will get a little information. Starting July 1st, Idaho will employ a full-time man on weed research.”
[Delena's commentary: This is shocking information. That the states were unleashing a new chemical on the environment, with so little research available, is alarming.]
Mr. H.E. Morris, from the Botany Department at Montana State College: “I don’t have very much to report due to the fact that our labor shortage has been very keen, and we have had a very difficult time even keeping a skeleton organization on our weed control. However, we are branching out considerably on our selective sprays on peas and the results appear very encouraging. On grain, we have been using Sinox principally, but have a set of experiments outlined now where will we will use 2,4-D.”
Mr. V.H. Freed, from the Experiment Station, Oregon State College: “in Oregon,… we have tried 2,4-D on wild gorse and it won’t touch it. In the preliminary work, the oils seem to be one means of controlling the plants, and I imagine it will take several applications to kill it… I don’t think that we can ever eradicate the plant economically, I believe without question that it is one of the toughest plants ever encountered in Oregon or any place.”
Mr. Chester E. Otis, Assistant Extension Specialist in Farm Crops, Oregon State College: “We can never hope to get very far in weed control work without our planned and financial research program. Weed control has been a sort of stepchild and in many instances when it comes to research work, we are just kind of skimming the surface. So far most of this meeting has been concerned with the chemical means of controlling weeds. That is one small phase of the whole weed problem. Most of the farming operations that are performed are performed largely to control weeds. We plow, we disc, we harrow. These are all cultural methods of weed control and must be given more consideration in our research work.”
[Delena's commentary: It is striking that Oregon was the only state, in the 1942 Conference, to sound the alarm about the use of arsenicals. And once again, it is one of the few states to express concern about the tendency of most states to focus primarily on the use of chemicals in weed control.]
Mr. George L. Hobson, Utah Department of Agriculture: “I would to say in general… that the cultural weed program… is going forward as rapidly and with as much interest as it has done in the past. There is a continuous demand and a growing demand for cultural work and also with reference to chemicals. Our people are desperate for chemicals. They are using all they can get hold of and I think the general interest is increasing constantly… I think generally we are going to have all the money we can use. The money matter is not a serious thing in our state, but our problem is the lack of equipment and labor.”
Mr. Charles D. Gaines, Washington Department of Agriculture: “One of the important developments in the state of Washington in this last year was the effectiveness of the work of the California Chamber of Commerce, which resulted in the loss of our weed specialist. I may say the general sentiment toward weed control is increasing quite rapidly and I’m hoping that we can really do something in the next two or three years to get statewide weed control work in Washington.”
[Delena's commentary: Apparently California had hired Washington’s weed specialist, which emphasizes the lack of experienced experts in this relatively new field.]
Mr. Bruce J. Thornton, Experiment Station at Colorado A&M: “I think the two greatest things we have from this meeting is, first, the danger of applying 2,4-D, which is much greater than I anticipated, and the possible uses that may be made of it, which is also greater than I anticipated… In Colorado we have done a thing very similar to Idaho. We are furnished each county with a uniform test involving four treatments and four dates of application... Our cultural work is going on more rapidly than before. We are entering in on this 2,4-D program, just getting started, so information is badly needed. This meeting will be of great value.”
Mr. George B. Harston, Wyoming Department of Agriculture: “I believe the outstanding development in Wyoming is the fact that our experimental station has taken a step toward doing experimental work towards weed control. The research man… plans to carry on some work with 2,4-D... I find that the farmers in Wyoming are very weed conscious. In fact, they are going out and buying this material and are putting it on their land. We are stepping cautiously as a department. We will carry on with the weed cultivation program, in the methods we have tested in the past, and I hope that we can benefit with the information.”
Mr. Thornton: “We are contemplating taking some fundamental work with using electricity with weeds. If you have any ideas we would appreciate your help.”
Mr. George E. Bradley, from Idaho, with the U.S. Agricultural Adjustment Agency: “We in the AAA have found where we can get the cooperation with your weed control organizations, we can get the job done. Where we don’t, a lot of money has been spent for nothing. I can say frankly that AAA is not interested in spending money for nothing in weed control. With the amount of money allocated it has been the general policy to keep weed control a practice of first priority. I hope that you folks know that with our limited allocation of funds, we don’t do all the work that is desirable… I would also like to mention, this weed control is too big for any one outfit or any one agency. I think perhaps if we all work together on it, we can get something done. It is pretty hard to sit down and write a report on weed control when we have been working on for 8 years and still there are considerably more weeds than when we started in.”
Summary of the Thursday afternoon session:
Mr. Kuhns: “Tomorrow we are having an all day session.. regarding seed law enforcement and modification… We would like to invite any and all of you to stay over and meet with us tomorrow. One thing that we will give particular attention to is the unifying of our state noxious weed lists in relationship to our seed law. As most of you know, every state has a little different list and it makes for confusion in our inter-state movement of seed. Last year we made a little start on working on a uniform list… Tomorrow we are going to try to come to a more definite conclusion.”
Some discussion of the time and location for next year’s conference ensued. Then the committee that had been working on some resolutions submitted the following, which were approved by the conference members:
The afternoon ended with a tour of some heavily weeded areas in Ada County, Idaho.
Links to other archival minutes:
Minutes of the 7th Annual Western Weed Control Conference, Boise, Idaho, June 6-7, 1945
Slade Franklin, Wyoming Department of Agriculture Weed and Pest Coordinator, loaned these archival minutes to Dr. Delena Norris-Tull. The original minutes were typed up documents from the 1940s. Dr. Norris-Tull transcribed and summarized the minutes, and added commentary throughout.
84 individuals attended this conference, many more than in years past. Representatives from various county and state agencies, scientists from various universities, and representatives of several chemical industries attended. No landowners (farmers or ranchers) seemed to appear on the list of guests. Only a few representatives from federal agencies attended: the Boise representative from the Bureau of Reclamation, and the US Forest Service agent from Ogden, Utah, and the US Indian Service Extension Supervisor from Salt Lake City. One international guest attended, Enrique Summers, from Peru.
The following states sent representatives to the conference:
- California
- Colorado
- Idaho
- Montana
- Nevada
- Oregon
- Utah
- Washington
- Wyoming
No representatives from Arizona or New Mexico were present.
Report of the Treasurer: Balance on hand: $467.10
Summary of the Wednesday sessions:
The Governor of Idaho welcomed the conference attendees and recommended that the representatives of the various agencies, “I hope that you men here from the different states will agree and try to interest the federal government, not only in support of an eradication program, but in financial support... The federal government owns much of this land. I think the federal government should be solicited to support this program. Out of this war will undoubtedly come some materials that will be more effective than any we have had up to date…”
Mr. Walter S. Ball, Chief of the California Department of Agriculture, Bureau of Rodent and Weed Control and Seed Inspection, gave a report regarding the development of the North Central States Weed Control Conference. This conference was called to organize 13 of the North Central states for the purpose of closer coordination and cooperation, very similar to the Western Weed Control Conference. Mr. Ball was asked to meet with the group to assist them in organizing, and he reported that their organization is set up in a similar manner, and for a similar purpose, as the Western Conference. Nearly 100 agency researchers and regulatory representatives, including several representatives from federal agencies, attended the conference. This is only the second region-wide weed control organization that has come into existence, with the Western Weed Control Conference being the first. That now brings 24 states into a coordinated effort at weed control.
In opening comments by Mr. C.H. Schrader, Department of Agriculture for Minnesota, he pointed out that, “If the weed losses in the United States estimated by the US Chamber of Commerce were $3 billion in 1930, we can easily suspect that they are now near $5 billion, or an average of more than $100 million per state…”
Mr. Ball described a speech by the representative of the US Department of Agriculture, Dr. M.A. McCall, in which he pointed out that while this conference focused on control of bindweed, at least 30 plants can now be considered noxious weeds. Dr. McCall mentioned Johnson grass, Russian knapweed, white top, and poverty weed, and stated that, “More than 2,000,000 acres of good agricultural land (are) virtually out of production because of noxious weeds... The Bureau of Reclamation spends more than $100,000 a year dragging weeds out of irrigation canals and drainage ditches...” He also mentioned that there are about 39 species of shrubs and trees now infesting some 10,000 acres of good pasture or rangeland.
Mr. Ball pointed out that a number of researchers attended, and gave reports, at the conference. The conference attendees pointed out the value of the research projects, and the networking opportunities for the researchers themselves.
He described a report by Mr. F.L. Timmons, the Chairman of the Research Committee, who listed the following areas needed for immediate research: “the development of a cropping system and rotation for the control of annual weeds; development of inexpensive methods of weed control on low valued lands; development of methods for the control of erosion during the eradication of perennials; the improvement of tillage machinery; the continuous testing of herbicides to determine their relative effectiveness…; the improvement of machinery for the application of dry material;… research on the occurrence of weed seeds in crop seeds and in feed grains;… the improvement of machinery for cleaning crop seeds.”
Mr. Ball quoted a report from Mr. L.W. Kephart: “One of the brighter aspects in the post-war weed picture is the probability that new chemical weed killers will be available of a variety and potency which we have not heretofore known… Weed eradication, as a science, has always lagged far behind other kinds of pest control in the development of technical aids, and our knowledge of the nature and utilization of herbicides is crude indeed by comparison with the highly intricate knowledge of insecticides, fungicides, germicides, and the like... (In the past 50 years) scarcely a dozen men have had the opportunity to give their full time and thought to the possibilities of chemicals in the control of weeds. As a result, the science of chemical weed control is still elementary and farmers have had available for their use, at least until very recently, only such unimaginative materials as arsenic, chlorate, sulfuric acid, and petroleum oil.” Mr. Ball reported that, “Some of the materials Mr. Kephart mentioned which will be in the field for further research are the sulfur compounds, the acetic acids, the aldehydes, organic peroxides, formates, oximes, chlorinated hydrocarbons, chlorinated phenols, and the dinitro compounds.”
Mr. Ball summarized several reports on weed control, as follows:
Nebraska: “Crop losses in past years due to (bindweed) have been millions of dollars… In 1943… the estimated loss exceeds $1,960,000. This estimate was made on the basis that this weed reduced corn yields 40%, wheat twenty 25%, oats 35%, barley 40%, and alfalfa and rye each 20%.”
Kansas: “from 1939 to 1943 inclusive,… bindweed has been eradicated on an average rate of about 10,000 acres per year… by cultivation... The total of bindweed eradicated, including cultivation, the use of sodium chlorate, and by special methods, was 53,390 acres.”
“Of the many reports which were given (by states)… practically all of the successful programs with those under district organization, such as the Nebraska program where weed eradication districts are set up as subdivisions of the state. In some states, however, this type of organization is set up by counties.”
“Another program was carried out by Dr. L.M. Stahler, who initiated statewide tests where only two herbicides other than sodium chlorate showed any promise in Minnesota, these being a ammonium sulphamate and Borax. One of the interesting points in his results was that 1 pound of chlorate was equal to 5 pounds of Borax in effectiveness on the control of bindweed… He found, however, that there was a wide variation in the efficiency of either Borax or chlorate alone and that recommendations of the rates of applying any of these should be made with care. I mention this work primarily because, other than the extensive use made of Borax in California, the work done originally by Mr. R.N. Raynor, there has not been intensive research carried on in so wide a scope as this in Minnesota.”
Mr. Ball summarized a report by Mr. A.K. Hepperly, Agricultural Agent of the C.B. & Q. Railroad, who found that the railroads’ use of chlorate to eradicate weeds are “so erratic that it requires so much labor for the original application and the follow-up treatments, and that the seedling problem, together with the fire hazard of sodium chlorate, makes it fall far short of a solution to the railroads’ problem of weed eradication… Considerable Borax has been used on the railroad with good results… inspection during the summer of 1943 showed good kill at most locations, some of which were 100%. Inspection in 1944, however, showed that Borax can be as erratic as sodium chlorate.”
Mr. Ball also learned that, “it appeared that all the states had some type of laws and regulations but there were very few states that had the manpower and the facilities for the enforcement of such laws.”
Report by Mr. Alton S. Craft, UC Davis, on herbicidal properties of oils:
“Oils are used as general contact herbicides for pre-emergence spraying in vegetable crops and for general weed killing on fence lines, road sides, and other places where plant growth is undesirable. They are also used as selective sprays against weeds in such crops as carrots, celery, and other members of the carrot family. They are used as carriers for denitro compounds and other phenolic herbicides. Their latest use is as carriers for the hormone weed killer, used in the control and eradication of cattails, tules, and other weeds that are difficult to wet. Finally, they are used in many horticultural sprays designed to kill insects and fungi. There is a real need for information on the toxic properties of oils as well as on their function in the spread and penetration of other pesticides.
“There are several aspects to a consideration of oil toxicity. First, there are two types of toxicity, namely acute and chronic toxicity. Second, there is the question of dosage as it relates to the physical properties of wetting and spreading to the chemical factors of composition. Selectivity is a third aspect. As with other herbicides, selectivity of oils entails a quantitative relation between dosage and chemical composition. Finally, there is the problem of composition as related to physiological effect. This has been studied by comparing the toxic properties of many oil fractions, and by the use of pure compounds, insofar as these have been available.
“The rapid killing of contacted tissues by oils is termed acute toxicity. It is characterized by a discoloration of the tissues, from a live green to a dead green or gray, accompanied by death. It is always manifest within a few hours after spraying and reaches a maximum within two or three days.
“Chronic toxicity results in a slow yellowing of leaves, killing of the growing point tissues, particularly in grasses, deterioration, and finally death of the plant. Tissue suffering from chronic injuries seem particularly susceptible to infection by fungi and often death of the plant is secondary, resulting from invasion by such parasites.
“Chronic toxicity seldom appears short of a 48-hour period and in many instances shows up only after a week or more. It has never been observed after use of light fractions within the gasoline range. These compounds volatilize rapidly from the plant. Severe chronic toxicity inevitably follows spraying with heavy, unrefined or lightly treated, petroleum fractions. Some chronic toxicity results from treatment with highly refined fractions. The only heavy liquid hydrocarbon used that has not caused chronic injury as a pure sample of n-cetane.
(Delena’s commentary: The rest of the report gives details of dosages, and information on which plants are readily killed by various oils. The report contained no information on how long the oils remained in the soil, and no information on longer term toxicity to desired plants and animals).
A report was given by Mr. R.B. Balcom, from the U.S. Bureau of Reclamation, on “Control of Waterweeds in Irrigation Systems.” (This is the same individual who reported at the 1941 conference, thus some information is redundant with the 1941 report). Key points are listed here:
“Early irrigation in the United States was, for the most part, confined to diverting water directly from natural streams. When these carried sufficient silt, the growth of water plants was inhibited. When simple diversions were no longer adequate, it became necessary to build dams to impound the water supply. The reservoirs thus formed act as suppling bases basins and the water coming from them is comparatively clear.
”Because of this and perhaps other influencing factors, the control of waterweeds has become increasingly difficult in many irrigation systems…
”Waterweeds seriously reduce the efficiency of irrigation systems... Because of their desilting action, these (waterweed) growths build up silt bars in the channel which further reduce the canal capacity and necessitate costly dredging. Also, as the water cuts around the silt bars, extensive erosion of canal banks and beds often occurs. Weeds cause ditchbreaks by retarding the flow of water until it overflows the banks, which results in delays in service and repairs as well as damage to crops by flooding and the loss of water so vital to our irrigated areas. A large amount of water is lost each year to transpiration of cattails, tules, and other emergent plants.”
The report listed the following plants as waterweeds: The floating weeds cause the least problems: water lettuce (Pistia stratiotos), water hyachinth (Eichornia crassipes), floating duckweed (Lemna species), water velvet (Azolla species).
The emergent weeds are more prevalent in drains than in canals or laterals: cattails (Typha), tules (Scirpus), parrot feather (Myriophyllum prosepinacoides), water primrose (Justicia), water cress (Nasturtium).
The submerged weeds cause the greatest problems, as they are more widely distributed and occur in both ditches and drains: coontail or hornwort (Ceratophyllum demersum) is the most troublesome unattached weed; troublesome attached weeds include pondweeds (Potamogaton), horned pondweed (Zanachellia palustris), water milfoil (Myriophyllum), waterweed (Anacharis canadensis), water buttercup (Ranunculus), spiney naiad (Najas marina), yellow stargrass (Heterantherea dubia), and muskgrass (Chara), and algae (which may be floating or unattached and become tangled with rooted plants).
The report extensively described implementation of the control methods, mechanical, drying, and chemical. Shading has also been used in some locations. It also described the use of the following chemicals: sodium arsenite and other arsenicals, copper suphate, and more recently, Benoclor (a chlorinated benzene). The following information was provided about the new chemical Benoclor:
“Tests were first conducted to determine if crop plants would be injured when irrigated with Benoclor-treated water. It was found that several times the strength of the concentration used for controlling waterweeds was necessary before even a slight injury (to crops) was sustained. No ill effects have been reported where the chemical has been used extensively but precautions are being taken to prevent it from reaching crop land. Turnouts along the section of ditch being treated are closed while the chemical blanket is flowing past. Where possible the treated water is turned into a wasteway and where these are not available the turnouts for about a mile past the end of the treated area are closed…
“… with certain established procedures in the use of Benoclor, many irrigation districts have been able to control their waterweeds growths more efficiently then by their previous methods. It has been of particular value during the present labor shortage. Instead of a crew of possibly 25 workmen being necessary, as in chaining and hand methods, the waterweed growths in an entire irrigation system can be controlled with Benoclor by two men.”
A lengthy description follows, for the application techniques, and on more recent formulations for Benoclor.
Mr. Balcom ended his report with the following prediction: “It is quite possible that scientific research will bring forth an even more effective chemical, one which will follow down into the root system of the waterweeds and kill the entire plant, as do the new ‘hormones’ on land weeds. It will be interesting to see how 2,4-D will effect water plants.”
[Delena's commentary: It is notable that at this time, a number of native plants were considered noxious weeds by the US Bureau of Reclamation].
Next, a representative from the USDA Bureau of Plant Industry, Soils, & Agricultural Engineering, Dr. McCall, was introduced. He stated that few federal resources are presently available to tackle the weed problem. He expressed willingness to ask the US Forest Service and other federal departments to increase financial support for weed removal on federally controlled lands.
[Delena's commentary: It has been apparent from these minutes and conversations with various State Agency representatives that the Federal Government has lagged way behind the States in tackling the weed problems].
Next, Mr. Lee Burge, from the Nevada Department of Agriculture, reported on the rapid spread of Halogeton in Nevada. This weed is spreading more rapidly than previously thought, and is germinating extremely rapidly.
Mr. J.R. Douglas, an entomologist from the US Bureau of Entomology and Plant Quarantine, gave a report on research on the beet leafhopper (Eutettix tenellus). The weed Halogeton glomeratus is closely related to Russian thistle (Salsola kali var. tenuifolia), which is a summer host for the beet leafhopper. In 1943, cage tests were conducted to determine how rapidly beet leafhopper will reproduce on Halogeton. And field counts were conducted, in Nevada and Utah in 1943 and 1944, in locations where the two plants grow in close proximity. In the 1943 data, both weeds hosted a similar count of beet leafhopper. But in 1944, Russian thistle hosted significantly more of the insects. Both plants are also a summer host of curly top virus. The research pointed to concerns that, as Halegeton spreads its range, it will also potentially increase the range of the beet leafhopper and curly top virus. At this point, little is known of the ability of Halegeton to compete with or replace native flora. It is a non-native plant from the Mediterranean.
Mr. A.F. Bracken, Extension Agronomist from Utah, mentioned that it has become a serious weed in Utah, and is of concern due to high levels of oxalic acid, which are potentially toxic to sheep and cattle.
Mr. Burge said that the plant first became known in the US in 1935, and has now spread to Utah, Idaho, Nevada, and Wyoming. He commented that feeding tests have shown that it can kill sheep.
Mr. Victor P. Rasmussen, from the Utah Department of Agriculture, stated that they studied its spread in Utah and determined that the state lacks the financial resources to reduce its spread.
The members agreed to form a special committee to create a resolution to request federal aid to reduce the spread of Halegeton.
Mr. Thomas H. Van Meter, from the US Forest Service, stationed in Idaho, gave a report on “Noxious Weed Control on National Forests.” The report is summarized:
“For many years the forest service has been combating plants poisonous to livestock and has included this control in the range management program. During the last 10 years, an invasion of noxious plants not native to our forest lands has been noted; and in some cases, spreading at an alarming rate. This invasion has been on past depleted areas that have not regained their normal vegetative balance, and control measures have been inaugurated on many areas. We believe that proper stocking and range management will generally take care of any infestation over a period of years.
“Undesirable or noxious weeds on National Forests fall into slightly different classes than those on cultivated areas. These weeds,… are classified as:
1. plants poisonous to live stock;
2. invasion plants;
3. plants noxious to adjacent cultivated lands.
“The more common poisonous plants found on forest ranges in the western states are: Larkspur (Delphinium species), death camas (Zygadenus), lupines (Lupinus species), water hemlock (Cicuta), loco (Astragalus & Oxytropis species), black laurel (Kalmia), sneezeweed (Helenium).
“One or more of these plants are native to any of our range lands and present few problems under proper management. Heavy livestock losses are caused by improper seasonal use, excessive grazing, or improper distribution.
“Grubbing (i.e., physical removal of tree stumps) has been effective as a control measure in areas of concentration, but excessive costs have caused the discontinuance of this method on most forests.”
He described some chemical treatments, using Borax on lupines (to prevent sheep losses in Idaho), and chemicals and oil spray on black laurel in California, and a variety of methods have been used to eliminate larkspur and water hemlock in Oregon and Washington.
“Invasion species that have caused no or little concern on forest lands are primarily: goatweed (Hypericum perforatum, also known as Klamath weed or St. John’s wort), mule’s ears (Wyethis amplexicaulis), false hellebore (Veratrum californicum), Medusa-head (Elymus caput-medusae).”
He reported new concerns about the spread of goatweed in California, Idaho, and Montana. Some treatment with Borax has been conducted. But Borax causes concern because it is expensive, and it causes soil sterility for three years.
He reported that, while mules ears and false hellebore, both native species, are not widespread, on depleted ranges, they can establish solid stands that complete with desireable forage plants. A light oil spray applied during early growth stages has been effective at eliminating these plants.
He expressed some concerns about the recent spread of medusa-head in California. It is not a desireable forage, when compared with Bromus tectorum, and medusa-head also poses a greater fire risk. Medusa-head has the potential to become a serious problem on range lands.
[Delena's commentary: This is such an interesting report, considering that Bromus tectorum, previously known as Anisantha tectorum, is cheatgrass, and is now considered a major invasive species problem, that is already causing high risks for wildfires in the west!]
He also described work being conducted to control Canada thistle and whitetop.
“When combating weeds, we have used sodium and calcium chlorate, Borax, oil spray, grubbing, and various other means. All have deficiencies that make them impractical for the widespread use which is required if the problem is to be successfully met. In Montana alone, it has been reported that over 100,000 acres need treatment on National Forest land, and other states reports similar acreages, so any proposed method for large-scale use should be reasonable in price, easy to apply, and nominal in its damage to soils and other vegetation.
”To date the Forest Service has financed their program from the limited range improvement funds allotted, as no direct appropriations have been made for this type of work.”
Mr. Ball reported on research being conducted in cooperation with the US Bureau of Entomology and Plant Quarantine on two biological control insects. These insects have been effective in use in Australia. He stated, “These insects have been brought into California, after thoroughly investigating the possibilities of their detriment to other plants or crops. A complete series of starvation tests have been carried out to prove that they would not be destructive to other plants. They attack nothing but Hypericum (goatweed). We do not know anything as yet about the natural predators, which may prey upon these insects. If they are present, our hopes for control will be very limited. We are not hoping to use these insects on those areas, at least at the present time, where we can carry on our regular program with Borax and cultivation.”
Dr. A.S. Crafts, from the University of California-Davis, stated: “We are going to have to have research programs and find what to do about this condition (the spread of goatweed). We must cooperate and consider these new problems with research. We are going to have to use biological methods wherever possible and more facilities may be needed.”
Mr. V.A. Cox, Superintendent Ada County Weed Control (Idaho), asked, “Isn’t it a fact that where they did control with those insects, after they destroyed the weed, your insects were destroyed and then the same process is repeated over again?”
Mr. Ball: “We have recognized that fact, but if these insects can reduce the infestation on the heavily invested ranges, we feel they are worthwhile. We recognize that there is a seed problem and know that (goatweed) seed will live on the soil for a number of years. Our tests show that this weed will continue to germinate after 10 or 15 years.”
Mr. W.L. Hendrix, President, Idaho Noxious Weed Association: “Does it do any good to try and burn Klamath weed?”
Mr. Ball: “Yes, we have tried burning and we have had successful results, where adequate dry material was present to carry the fire.”
Mr. W.W. Robbins, from the University of California-Davis: “Where these burning experiments were to be carried out, we ran into one difficulty that as soon you open the ground the (weed) seedlings come up like hair on a duck’s back. But there are indications that where we can get grass to come back and we get dry material to carry the fire that we can get some thinning. These experiments, …have not been completed, however, so that we have no data at present.”
Summary of the Thursday sessions:
Mr. C.T. Seeley, from the Agronomy Division of the University of Idaho gave a report on the new developments with the use of hormones in weed control. He described the use of 2,4-D:
“It wasn’t until 1941 that Nevada thought you might be able to use it for weed control, and it wasn’t until 1944 that any actual work was done,… as far as weed killers was concerned. 2,4-D was picked primarily because it happened to be one that was easily manufactured and was available in large quantities... Since our work was done with cargowax carriers,.. our results with certain types of weeds was quite promising, particularly…because of cost. At that time, the price of 2,4-D was very reasonable. It since has risen... On many of the root perennials we got very good results… The results were outstanding on dandelions and some such plants. Some of the biennials in the second year of growth were outstanding. At the same time, on the root stock perennials, we got a peculiar reaction. We got vertical root kill but not lateral. In most cases we got recovery (i.e., weeds growing back)… From other weeds in that group we got practically no results at all, possibly due to application too late in the season… We have 150 tests out so far this spring, and what they look like at present is no indication at all as to what they will look like three months from now. We have not been able to get the carrier… We did run into difficulties. One is soil effect that is showing up in many places. In other places, it is causing practically no trouble at all. Another thing that some run up against is that most of the preparations get into trouble in hard water. In some cases, it is apparently due to antagonistic salts in the water. In some, calcium precipitates need investigation. Probably the most susceptible has been morning glory and Canada thistle. In the lawn work more or less, we are doing quite a lot of work with 2,4-D as a selective material, and it is better than anything we have had. Some of the grass species have been injured by 2,4-D applications at high concentration, as we get some stunting and some burning. Whether or not it is a permanent injury, we do not know… The cost at the present time is out of line… The temperatures are frequently too low... One of the things that is bothersome in some sections is that water is a major factor and it is very difficult to get… What the (water) limits are we don’t know as a number of things have come up relative to temperatures. Every one who has worked with it notices that nothing happens with low temperatures.”
Mr. W.A. Harvey, of the University of California-Davis, gave a report on the effects of 2,4-D on soil. A research study of differing concentrations of 2,4-D on crop growth showed that different crops differ in their susceptibility to the chemical. “Oats survive at much higher concentrations than peas or sunflowers, and sunflowers tolerate higher concentrations than peas. However, by using a high enough concentration, it is possible to prevent growth of any of these plants. This is definite evidence that 2,4-D does sterilize soil to some extent, the amount of sterilization depending on the amount of chemical in the soil.
”The three soils (tested) also differ in the amount of toxicity shown by the chemical. The Stockton adobe clay shows the least toxicity or, putting it another way, it takes more of the chemical to show toxicity in this soil than in the others. The Hanford fine sandy loam shows the highest toxicity, and the Yolo adobe clay chosen intermediate toxicity…
”Thus we see that serious effects on crops are possible with very small amounts of the chemical in the soil. Now we don’t know yet how long this effect lasts in the soil. Apparently it lasts for 30 days at least and is definitely reduced in 60 days, but we are long way from having final data on it…
“In another year, we hope to have some of the answers but right now there are a lot of things we don’t know about 2,4-D.”
Various individuals asked more questions about this preliminary research. Mr. Harvey added that they have not yet done research on the rate of penetration of 2,4-D in the soils.
Dr. Crafts added, “With our past experience with leaching of chemicals in the soil, we have come to recognize two types of behavior. Arsenic will be fixed by most soils. On the other hand if you take nitrate and chlorate it will be distributed throughout the soil. 2,4-D may compare more with Borax which fixes loosely. We have tested eight California soils.”
Mr. Jerome Evans, from the Idaho Agricultural Adjustment Agency (AAA), asked: “Has anyone here any observances as to the effect of the 2,4-D on the microflora of the soil?”
Mr. Seeley: “I can give you some secondhand information...The Information I have is that it has pretty bad effects as far as soil bacteria is concerned, but very little effect on fungi.”
Mr. Robbins: “The bacteriologist at our station applied 2,4-D to his lawn. Following the application, he applied ammonium sulfate and he made the remark that he got no response out of the ammonium sulfate for a very long time, and he was wondering if (2,4-D) had any effect on the bacteria in the soil… We need to know more about that. Doesn’t this work indicate to you people that we had better go a little bit slow on our application of hormones to agricultural soil?… In the light of your work, what advice would you give (to farmers) with respect to seeding with alfalfa a few weeks after the application of hormones?”
Answer: “Farmers should be advised to proceed cautiously until more is known of the effects of 2,4-D to soils.”
Another report was presented on the use of 2,4-D in the wetter conditions in the eastern states, where they have had success with planting crops 6 weeks after applying 2,4-D.
Mr. Harvey gave a lengthy report on the differential response of various weeds to 2,4-D. A number of the “weeds” that were described are native plant species. Several individuals expressed concerns about using 2,4-D before more is known about soil sterilization and other effects on the soil and crops. Concerns were raised about the need for research on the effects on animals. Mr. R.N. Raynor, from California, reported, “We don’t have any experience with large animals, but we have made tests on small animals and the tests indicate that large doses by mouth are not injurious and applications through the skin are not injurious.”
[Delena's commentary: the lack of research on animals is alarming, as different species would react differentially to the toxic chemical, just as would different species of plants.]
Finally, a few brief state reports were given.
Mr. Buford E. Kuhns, from the Idaho Extension Service: “…We have supplied each of our county agents…with a number of what we call an information sheet. We’re asking them to carry on a little experimental work with these various 2,4-D preparations, and we are asking them to prepare a short information sheet, showing the location, date of application, type of soil, temperature, and all of the other factors that might be of interest, and give their notes on their observations... We will then assemble all that material and hope that we will get a little information. Starting July 1st, Idaho will employ a full-time man on weed research.”
[Delena's commentary: This is shocking information. That the states were unleashing a new chemical on the environment, with so little research available, is alarming.]
Mr. H.E. Morris, from the Botany Department at Montana State College: “I don’t have very much to report due to the fact that our labor shortage has been very keen, and we have had a very difficult time even keeping a skeleton organization on our weed control. However, we are branching out considerably on our selective sprays on peas and the results appear very encouraging. On grain, we have been using Sinox principally, but have a set of experiments outlined now where will we will use 2,4-D.”
Mr. V.H. Freed, from the Experiment Station, Oregon State College: “in Oregon,… we have tried 2,4-D on wild gorse and it won’t touch it. In the preliminary work, the oils seem to be one means of controlling the plants, and I imagine it will take several applications to kill it… I don’t think that we can ever eradicate the plant economically, I believe without question that it is one of the toughest plants ever encountered in Oregon or any place.”
Mr. Chester E. Otis, Assistant Extension Specialist in Farm Crops, Oregon State College: “We can never hope to get very far in weed control work without our planned and financial research program. Weed control has been a sort of stepchild and in many instances when it comes to research work, we are just kind of skimming the surface. So far most of this meeting has been concerned with the chemical means of controlling weeds. That is one small phase of the whole weed problem. Most of the farming operations that are performed are performed largely to control weeds. We plow, we disc, we harrow. These are all cultural methods of weed control and must be given more consideration in our research work.”
[Delena's commentary: It is striking that Oregon was the only state, in the 1942 Conference, to sound the alarm about the use of arsenicals. And once again, it is one of the few states to express concern about the tendency of most states to focus primarily on the use of chemicals in weed control.]
Mr. George L. Hobson, Utah Department of Agriculture: “I would to say in general… that the cultural weed program… is going forward as rapidly and with as much interest as it has done in the past. There is a continuous demand and a growing demand for cultural work and also with reference to chemicals. Our people are desperate for chemicals. They are using all they can get hold of and I think the general interest is increasing constantly… I think generally we are going to have all the money we can use. The money matter is not a serious thing in our state, but our problem is the lack of equipment and labor.”
Mr. Charles D. Gaines, Washington Department of Agriculture: “One of the important developments in the state of Washington in this last year was the effectiveness of the work of the California Chamber of Commerce, which resulted in the loss of our weed specialist. I may say the general sentiment toward weed control is increasing quite rapidly and I’m hoping that we can really do something in the next two or three years to get statewide weed control work in Washington.”
[Delena's commentary: Apparently California had hired Washington’s weed specialist, which emphasizes the lack of experienced experts in this relatively new field.]
Mr. Bruce J. Thornton, Experiment Station at Colorado A&M: “I think the two greatest things we have from this meeting is, first, the danger of applying 2,4-D, which is much greater than I anticipated, and the possible uses that may be made of it, which is also greater than I anticipated… In Colorado we have done a thing very similar to Idaho. We are furnished each county with a uniform test involving four treatments and four dates of application... Our cultural work is going on more rapidly than before. We are entering in on this 2,4-D program, just getting started, so information is badly needed. This meeting will be of great value.”
Mr. George B. Harston, Wyoming Department of Agriculture: “I believe the outstanding development in Wyoming is the fact that our experimental station has taken a step toward doing experimental work towards weed control. The research man… plans to carry on some work with 2,4-D... I find that the farmers in Wyoming are very weed conscious. In fact, they are going out and buying this material and are putting it on their land. We are stepping cautiously as a department. We will carry on with the weed cultivation program, in the methods we have tested in the past, and I hope that we can benefit with the information.”
Mr. Thornton: “We are contemplating taking some fundamental work with using electricity with weeds. If you have any ideas we would appreciate your help.”
Mr. George E. Bradley, from Idaho, with the U.S. Agricultural Adjustment Agency: “We in the AAA have found where we can get the cooperation with your weed control organizations, we can get the job done. Where we don’t, a lot of money has been spent for nothing. I can say frankly that AAA is not interested in spending money for nothing in weed control. With the amount of money allocated it has been the general policy to keep weed control a practice of first priority. I hope that you folks know that with our limited allocation of funds, we don’t do all the work that is desirable… I would also like to mention, this weed control is too big for any one outfit or any one agency. I think perhaps if we all work together on it, we can get something done. It is pretty hard to sit down and write a report on weed control when we have been working on for 8 years and still there are considerably more weeds than when we started in.”
Summary of the Thursday afternoon session:
Mr. Kuhns: “Tomorrow we are having an all day session.. regarding seed law enforcement and modification… We would like to invite any and all of you to stay over and meet with us tomorrow. One thing that we will give particular attention to is the unifying of our state noxious weed lists in relationship to our seed law. As most of you know, every state has a little different list and it makes for confusion in our inter-state movement of seed. Last year we made a little start on working on a uniform list… Tomorrow we are going to try to come to a more definite conclusion.”
Some discussion of the time and location for next year’s conference ensued. Then the committee that had been working on some resolutions submitted the following, which were approved by the conference members:
- Resolution on Federal Research for Weed Control, “recommending that the United States Congress create a Division of Weed Research,” to be established within the Bureau of Plant Industry, Soils, and Agricultural Engineering;
- Resolution on Funds for Federal Weed Control, “requests the Federal Government to provide funds for an effective weed control program on all Federal land.”
The afternoon ended with a tour of some heavily weeded areas in Ada County, Idaho.
Links to other archival minutes: