Internal dormancy (the state of internally arrested growth) in western ironweed (Vernonia baldwini Torr.) buds consisted of a recurring annual cycle of high and low activity with transition periods. Trends in sprouting activity were similar regardless of whether activity was measured by sprouting of buds following removal of stems in the field, or by sprouting of rhizome section buds in moist sand. Bud activity measurement was quantitatively different by the two methods, however, and the apparent period when internal dormancy developed also differed. A number of interdependent factors modified activity. At various points in the cycle, the stem apex inhibited bud growth; the stem alone inhibited bud growth; a transient block due to immaturity occurred in some buds; and two temperature-related blocks occurred. Bud age and location on the rhizome had little effect on activity. During the period of internal dormancy, sprouting of buds apparently stimulated activity of adjacent buds. Temperature greatly affected expression of internal dormancy; prolonged moist cold treatment eliminated it.

New Line Early Perfection peas (Pisum sativum L.) in the 10th-node stage were treated with a foliar broadcast application of 1 lb/A of the sodium salt of carboxyl carbon-14 labeled 4-(2-methyl-4-chlorophenoxy) butyric acid (MCPB*). Direct counting of C14 indicated that MCPB* equivalent to 8.4 ppm on the fresh weight basis was in or on the pea tissue immediately after treatment. The concentration declined rapidly for 6 days following treatment and then at a reduced rate until shelled pea harvest 5 weeks later. Translocation of C14 was studied by autoradiography. Most of the labeled material was retained at the application site. Very little was translocated to the new growth or into the pea seed. The plants retained C14 equivalent to 0.4 ppm MCPB* at the time of harvest with a concentration in the shelled peas of not more than 0.1 ppm.

Crabgrass (Digitaria spp.) control by different herbicides in field experiments varied from 84 to 100%. These extremes were not significantly different. Greenhouse studies showed that increased moisture content in soils may increase the growth rate of crabgrass seedlings so that they may escape herbicidal injury. Effects of herbicides on root stunting were similar in both dry and wet soils, indicating immobility of the herbicides under these experimental conditions. Competition between mature bluegrass plants and crabgrass seedlings was an important determinant of effective crabgrass control with preemergence herbicides.

This is a most timely question because of the importance of herbicides in modern agriculture, the quantity of resources in industry and the public institutions devoted to testing, and the sizeable number of new materials appearing each year. Before examining the role of the experiment stations in herbicidal testing, let me make clear that I am restricting my comments to known materials. Testing so-called unknown materials to identify potential herbicides is clearly incompatible with the teaching and research role of a university. Such research, if it may be called research, is oriented to products whereas the stations' applied research in this area should be oriented to problems faced by the agriculture and homeowners of the state.

All will agree testing is necessary to determine if a herbicide will do the job under local conditions. In brief, the present program involves: (1) screening for herbicidal activity and preliminary determination of effective rate and crop tolerance by industry; (2) research by university personnel on rate and method of application and on crop tolerance, and; (3) demonstrations or field tests by university and industry personnel to further test the material and to promote use of it by farmers. There is some duplication among these three. Furthermore, steps 2 and 3 are essentially repeated in each state having the particular weed and crop situation. Yet, we find that recommendations among these states are frequently the same. Where this is the case, it is apparent that all states need not have done the testing. In view of this duplication and of changes taking place in universitites and the pesticide industry, an honest appraisal of the overall testing program and of stations' role in it seems in order. Let us look at some of the things which bear on the stations' involvement in testing programs.

A chromatographic procedure for detecting 4-amino-3,5,6-tricholorpicolinic acid (picloram) residue to a sensitivity of approximately 0.05 ppm in soils is described. Picloram is extracted from soil as the free acid and methylated with boron trifluride-methanol reagent. Data indicate that the amount of herbicide which actually reaches the soil may only be 10% of that applied to dense stands of oak. Rainfall was an important factor in determining the movement and persistence of picloram. Picloram was detected to a depth of 24 in within 6 weeks after application. No detectable residues were found in the upper 24 in of soil after one year with rates as high as 8 lb/A.

Surface applications of 4-amino-3,5,6-trichloropicolinic acid (picloram) were made at 5 rates on 3 soil types. The picloram-treated areas were sampled 3 times after herbicidal application to determine the extent and movement of herbicide residues. The region of highest picloram concentration in a heavy- and medium-textured soil, when sampled 9 and 15 months after application, was near the surface. On the light-textured soil, picloram moved more completely through the surface 2 ft of soil with greatest herbicide concentrations generally found at the deepest sampling depth. Applications of picloram were dissipated faster at low rather than at high rates on all 3 soil types. Concentrations of phytotoxic residues at the end of the study period were greatest in the heavy-textured soil with the highest organic content.

We developed a technique for obtaining buds which were alike except for the state of dormancy, and measured aerobic respiration and enzyme activities in internally dormant, and active but non-growing, buds of western ironweed (Vernonia baldwini Torr.). In both types of buds respiratory quotient was centered at about 1.2, and slightly higher in the active buds. Respiration rate paralleled specific malic dehydrogenase activity; both were lower in dormant than in active buds. Specific peroxidase and polyphenol oxidase activities did not differ markedly in dormant and in active buds. Respiration rate and all enzyme specific activities increased markedly when active buds were permitted to grow.

In the past, Agricultural Experiment Stations have routinely evaluated new herbicides and other pesticides to determine their potential place in solving local agricultural problems. This type of work has become very controversial in recent years. Many universities will no longer work with herbicides during the evaluation stages on field problems and limit most or all of their herbicide research to more basic laboratory oriented programs. Since Oregon State University has a major project on the evaluation of new herbicides, there must be some justification for this in a university's work program. An effort will be made to point out some of the reasons for the Oregon State University program and try to analyze the pros and cons of this topic from the university standpoint.

Several steps are possible in testing herbicides, or what might be called steps in testing during the herbicide development period. The first step will be called early evaluation of new products. The advantages for a university becoming involved in this early phase testing work is that it builds a close working relationship with the chemical industry. This working relationship provides support for students, which in itself is important to the future of the weed control field. There is deep concern over the small number of students that are being trained in weed control, particularly those that are agriculturally oriented. If some change is not made in the lack of sufficient numbers of trained students from universities, a serious crisis in both industry and university staffing will result.

Two-chloro-4-ethylamino-6-isopropylamino-s-triazine (atrazine), 5-bromo-3-sec-butyl-6-methyluracil (bromacil), and 6,7-dihydrodipyrido-(1,2-a:2’,1′-c)-pyrazidiinium salt (diquat) significantly inhibited photosynthetic C14O2-fixation to varying degrees in corn (Zea mays L., var. Dixie 18), cotton (Gossypium hirsutum L., var. Deltapine), and soybeans (Glycine max (L.) Merr., var. Lee). Atrazine treatments of 10 ppm overloaded the protective mechanisms in corn and cotton. Both 1 and 10 ppm of atrazine reduced C14O2-fixation to less than 5% of controls in soybeans, a sensitive species. One ppm of bromacil and of diquat reduced C14O2-fixation in all three crops, but diquat was less inhibitory than either bromacil or atrazine. Except for diquat on corn, herbicides had no significant effect on C14O2-fixation in the dark. Treatments in which photosynthetic C14O2-fixation was 5% or more of controls had little effect on the kinds or relative amounts of C14-labeled compounds produced. Only the total amount fixed was reduced. Treatments, in which photosynthetic C14O2-fixation was less than 5% of controls, caused a significant reduction in the relative amounts of sucrose and alanine produced; however, the relative amounts of malic, aspartic, and glutamic acids increased.

Low-volatile and high-volatile esters of 2,4-dichlorophenoxyacetic acid (2,4-D) were sprayed on separate pastures at about double the usual rate. Milk from cows grazing these pastures contained from 0.01 to 0.09 ppm 2,4-D during the first 2 days after spraying and lower amounts thereafter. Residues in milk from cows put into the pastures 4 days after spraying were below 0.01 ppm, the practical limit of precision of the method used. Residues of 2,4-D, in or on forage, declined rapidly during the experiment. Almost all the 2,4-D in or on forage was hydrolyzed to the acid form in samples of forage taken within one-half hour after spraying with the butyl ester of 2,4-D, and about 75% after applying the 2-ethylhexyl ester.

In the greenhouse, picloram (4-amino-3,5,6-trichloropicolinic acid) prevented germination of side-oats grama [Bouteloua curtipendula (Michx.) Torr.,] big bluestem (Andropogon gerardi Vitman), switchgrass (Panicum virgatum L.) and blue grama [Bouteloua gracillis (HBK) Lag.] when applied preemergence. When applied at 1.5 lb/A or more at the two-leaf stage in the greenhouse and field, picloram significantly reduced plant numbers of all species. Of the four species big bluestem appeared to be the most tolerant to picloram in the seedling stages. Germination was reduced when 2,4-D (2,4-dichlorophenoxyacetic acid) was applied preemergence to side-oats grama and the plant numbers of this species and switchgrass were reduced when treated at the two-leaf stage.

The application of picloram to established native range did not reduce forage production or desirable plant frequency. All treatments reduced forb production. Picloram gave very good control of western yarrow (Achillea lanulosa nutt.), white heath aster (Aster ericoides L. nutt.), and western ironweed (Vernonia baldwini Torr.). White sage (Artemisia ludoviciana nutt.) was resistant to 4 lb/A of picloram.

As a representative of the chemical industry, this subject is a rather difficult one to discuss. When one stops a moment to think about the role of the university in herbicidal testing, immediately he realizes that this probably never has been defined and it appears for the most part the administration and research personnel of each university follow the road that is the best of their liking. Far too often, they do not stop and ask themselves whether they really are taking the proper route.

In discussing this topic, one can take the approach that all universities, and some are in this category, are doing an excellent job and compliment everyone that an adequate job is being done. Or one can conclude that the universities should not be doing field evaluations (and please understand this is in the minds of a few university administrators) or the answers to the field problems can be solved in the laboratories; or finally, one can conclude that the universities are not doing a proper job and that considerable improvement must take place. Perhaps I will make some new enemies today (although the Chairman, Dr. Ries, indicated I could take any approach I preferred), but I am of the opinion that our university and experiment station system primarily is not doing a proper job in testing herbicides and that they must take a more active role in the future than they have in the past.

The relationship of atrazine (2-chloro-4-ethylamino-6-isopropylamino-s-triazine) and diuron [3-(3,4-dichlorophenyl)-1,1-dimethylurea] decomposition to microbial activity in two soils was determined. Microbial responses to temperature, added energy material, and time were measured by evolution of CO2 from herbicide-treated soil samples. Evaluation of herbicide decomposition was made by bioassay and radioassay. Herbicide inactivation was directly related to metabolism of soil organic carbon. Larger amounts of herbicide were inactivated per unit of soil carbon metabolized in Norfolk loamy sand than in Decatur clay loam. This was associated with less soil specific surface and consequently greater concentration of herbicide on soil particle surfaces in Norfolk compared to Decatur soil. Addition of microbial energy sources accelerated decomposition of atrazine and diuron in both soils. Herbicide decomposition was closely associated with repeated additions of energy material, indicating an incidental or nonpreferential involvement in microbial metabolism. Decomposition of atrazine doubled with each 10-degree rise in temperature from 10 to 30 C, paralleling the response of soil organic matter decomposition. Diuron decomposition approximately tripled with each 10-degree rise in temperature.

In the greenhouse, 20% granular isopropyl N-(3-chlorophenyl) carbamate (CIPC) at 6 lb/A provided 100% dodder control for 3 to 6 weeks. In the field, 95 to 100% control persisted beyond the expected soil life of CIPC because shade from the crop plants inhibited dodder development and dry soil reduced dodder germination. Effective control required uniform distribution on the soil before the dodder was wrapped on the host plant. CIPC was most effective when applied on the soil surface; incorporation ½, 1½, or 3 in deep reduced its effectiveness. It controlled dodder well if applied to moist soil but was less effective when the soil surface was dry. Partial shade from the crop at the time of application increased the effectiveness of CIPC. Under certain undefined conditions, CIPC applied to the soil injured attached dodder. However, it was consistently effective only on dodder seedlings before attachment.

A microcoulometric gas chromatographic method with a sensitivity of 0.01 ppm is described for the analysis of 2,4-dichlorophenoxyacetic acid (2,4-D) in milk and forage. The method will analyze 2,4-D as the acid, ester, and bound form from a single sample. Results show the superiority of this method over previous procedures. The formation of 2,4-D ethyl ester from the butyl ester in forage is discussed.

Although selectivity was low, 3-(3,4-dichlorophenyl)-1,1-dimethylurea (diuron) gave excellent preemergence weed control when castorbeans (Ricinus communis L.) were planted 2 or 3 in deep. Excellent weed control with little crop injury by 3-amino-2,5-dichlorobenzoic acid (amiben) was provided also and selectivity was not affected by depth of planting.

A study was made with glucose-1-C14, glucose-6-C14, and glucose U-C14 to determine quantitatively the effects of 2,2-dichloropropionic acid (dalapon) on glucose utilization in roots and shoots of one-week-old barley seedlings. An attempt also was made to determine the major pathway of glucose metabolism involved. Dalapon apparently did not change the normal pathway of glucose metabolism but interferred with glucose utilization as evidenced by differences in radioactivity of sugars and organic acids. Partial blocks may be operative initially at the beginning of the glycolytic pathway and subsequently in the Krebs cycle.

Where sugar beets followed the year after one year's use of 2-chloro-4-ethylamino-6-isopropylamino-s-triazine (atrazine), the carryover, measured by beet response was correlated with the time, the method, and the rate of atrazine used, and the time of plow-down. Where beets were the second crop after an atrazine application, carryover was correlated with the rate of application only. Carryover was greatest following two consecutive years' use of atrazine. Sugar beets were more sensitive to atrazine than were soybeans, navy beans, or oats.