When buds on the rhizome of quackgrass [Agropyron repens (L.) Beauv.] were released from apical dominance either by increasing the nitrogen supply to the parent shoot (from 5.25 to 210 ppm) or by raising the humidity around the rhizome (from 55 to 100%), the growth response of the buds was closely correlated with their uptake of foliar-applied 14C-labeled glyphosate [N-(phosphonomethyl] glycine]. The 14C level in the buds, expressed on a dry-weight basis, was greatest in the youngest, most rapidly growing bud at the apical node and decreased in successively older buds along the rhizome. A similar gradient was shown by the 14C content of the associated rhizome nodes. The high-humidity treatment also increased the total amount of 14C that was translocated into the rhizome, whereas increasing the nitrogen supply, while promoting 14C uptake by the buds, markedly reduced the amount in the rhizome nodes and in other parts of the plant. This nitrogen-induced reduction in translocation was associated with a reduction of about 30% in uptake of the herbicide by the treated leaves.

Cotton (Gossypium hirsutum L.) response was evaluated when propanil (3′,4′-dichloropropionanilide), thiobencarb {S-[(4-chlorophenyl)methyl] diethylcarbamothioate}, butachlor [N-(butoxymethyl)-2-chloro-2′,6′-diethylacetanilide], oxadiazon [2-tert-butyl-4-(2,4-dichloro-5-isopropoxyphenyl)-δ2-1,3,4-oxadiazolin-5-one], bifenox [methyl-5-(2,4-dichlorophenoxy)-2-nitrobenzoate], acifluorfen {5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-nitrobenzoic acid}, and metribuzin [4-amino-6-tert-butyl-3-(methylthio)-as-triazin-5(4H)-one] were applied over-the-top at simulated drift rates at two growth stages during 1975 to 1979. No rate of butachlor or thiobencarb injured cotton. The order of phytotoxicity for the herbicides applied to cotyledonary cotton was propanil > metribuzin > bifenox > oxadiazon > acifluorfen > butachlor = thiobencarb. Herbicides injured cotton less at the five- or eight-node stage than at the cotyledonary stage. Injury was more severe in seasons of wet or cold weather during early plant development.

“We're Number 1” has become an oft-repeated claim in sports, but agricultural research in the United States must admit to being only a poor Number 2 (9). The Soviet Union exceeds the United States 3.4 to 2.2 in percent of gross national product invested in agricultural research, 60000 to 12000 in numbers of agricultural scientists, and 150000 to 13000 in support personnel (9). Furthermore, agricultural scientists hold eminent positions in the Soviet Union and are regularly admitted to the Soviet Academy of Science, whereas few United States agriculturists are elected to the United States National Academy of Sciences. This disparity is hard to understand in view of the importance of agriculture in the United States. For example, it is anticipated that in 1982 the United States will pay $60 billion for imported oil and that two-thirds of this will be paid for by agricultural exports (6). According to Schultz (8) in his address on socio-economic aspects of agriculture, “the future food supply is dependent in large measure on achievements in agricultural research”. It would appear that accepting second place to the Soviet Union in agricultural research is even more unacceptable than second place in space. This audience does not need to be convinced of the importance of agricultural research. We might, however, profit by enumerating some of the characteristics of a high quality research program. The comments I am going to make are not intended to be all inclusive and are primarily based on my observations of agricultural research in land-grant universities. Most of the comments are, however, equally applicable to other fields of research and to other agencies.

Ethylene-stimulated germination of witchweed [Striga lutea Lour. = S. asiatica (L.) O. Ktze.] seed first occurred after 13, 10, 6, 3, and 2 days of conditioning in moist sand at day/night temperatures of 20/14, 23/17, 26/20, 29/23, and 32/26 C, respectively. Maximum germination percentages in these regimes were 0.5, 3, 20, 24, and 37%, respectively. No germination occurred at 17/11 C. Witchweed seed survived in sand frozen for 7 weeks at −7 or −15 C and subsequently germinated in response to ethylene or in the presence of corn (Zea mays L., ‘DeKalb B73 × Mo.17H′) roots. The parasites emerged from the soil and flowered when maintained at 29/23 C after the termination of the freezing treatments. In other experiments, witchweed parasitized corn and/or sorghum [Sorghum bicolor (L.) Moench ‘DeKalb E-59+′] root systems in a sandy loam under 26/17, 26/20, 29/20, 32/23, and 32/26 C day/night regimes. Witchweed emerged from the soil with 26/20, 29/20, 32/23, and 32/26 C and flowered with 26/20, 32/23, and 32/26 C day/night regimes. Underground development and subsequent emergence of the parasites were substantially reduced with day/night temperatures below 29/20 C. Winter soil temperatures and growing season soil and air temperatures are unlikely to limit the spread of witchweed into important corn- and sorghum-producing areas of the United States.

A field study was conducted with fluchloralin [N-(2-chloroethyl)-2,6-dinitro-N-propyl-4-(trifluoromethyl)aniline], profluralin [N-(cyclopropylmethyl)-α,α,α-trifluoro-2,6-dinitro-N-propyl-p-toluidine], and trifluralin (α,α,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine) at 1× and 2× rates in soybeans [Glycine max (L.) Merr.] for 2 consecutive yr to evaluate their persistence in soil and to determine their residual effect on rice (Oryza sativa L.). In another field study that was conducted to evaluate the effect of winter flooding on the persistence of 4× rates of the same herbicides, gas chromatographic analysis and bioassay procedures both revealed increased dissipation of these herbicides because of winter flooding. Flooding rice for 2 or 4 months during winter reduced the adverse effect from herbicidal residues. Laboratory studies evaluated the persistence and volatility of these herbicides at 4 and 25 C in two soils at three moisture contents (air-dried, field capacity, and flooded). The persistence of the three herbicides was similar in the field and in the laboratory and usually followed the order fluchloralin > profluralin = trifluralin. Volatility was most rapid with moisture at field capacity, but overall dissipation was most rapid in flooded soil. Significant dissipation and volatility losses of all three herbicides occurred at 4 C in flooded soil and in soil at field capacity. These studies indicated that winter flooding is effective in reducing the concentration of dinitroaniline herbicides in soil.

Field experiments were conducted at four locations to evaluate the efficacy of metribuzin [4-amino-6-tert-butyl-3-(methylthio)-as-triazin-5(4H)-one], simazine [2-chloro-4,6-bis(ethylamino)-s-triazine], buthidazole {3[5-(1,1-dimethylethyl)-1,3,4-thiadiazol-2-yl]-4-hydroxy-1-methyl-2-imidazolidinone} and 2,4-DB [4-(2,4-dichlorophenoxy) butryic acid] treatments for common dandelion (Taraxacum officinale Weber) control in established alfalfa (Medicago sativa L.). Most herbicides temporarily reduced common dandelion populations at all locations, but by the end of the first year only buthidazole reduced them on fine-textured soils, but buthidazole, metribuzin and fall-applied simazine reduced populations on coarse-textured soils. Only buthidazole controlled common dandelion in the year following application at all locations. Control of common dandelion did not consistently increase total forage yield or quality or increase alfalfa yield and stands compared to the untreated check. Buthidazole reduced alfalfa and total forage yield on coarse-textured soils.

Research on biological control of weeds in the United States began early in this century with the use of introduced insects to control the weed, lantana (Lantana camara L.), in Hawaii. The highly successful program for biological control of St. Johnswort (sometimes called “Klamath weed”) (Hypericum perforatum L.) in California by the use of introduced insects in the 1940's and 1950's caused increased interest in this approach to weed control. As a result of this increased interest, the United States Department of Agriculture (USDA) established two overseas laboratories to study arthropod natural enemies of a number of weeds that had been introduced into the United States – in Rome, Italy, in 1959; and near Buenos Aires, Argentina, in 1962. The recent and successful use of an introduced rust pathogen (Puccinia chondrillina Bubak & Syd.) to control rush skeletonweed (Chondrilla juncea L.) in Australia, and the production and utilization of pathogens for control of weeds in the United States, has spurred further interest in biological control.

Aerial applications of pelleted tebuthiuron (N-[5-(1,1-dimethylethyl)-1,3,4-thiadiazol-2-yl]-N, N′-dimethylurea} at 1 kg/ha to rangeland reduced canopy cover of the subshrub false broomweed (Ericameria austrotexana M.C. Johnst.) by 69 to 78%. Complete control was obtained with 2 kg/ha of tebuthiuron. Picloram (4-amino-3,5,6-trichloropicolinic acid) pellets applied at 2 kg/ha controlled false broomweed in two of four experiments; effectiveness of soil-applied picloram appeared to depend upon sufficient rainfall to move the herbicide into the soil soon after treatment. After the first growing season following application, density of herbaceous species tended to be higher in plots receiving either herbicide than in untreated plots. Picloram suppressed curlymesquite [Hilaria berlangeri (Steud.) Nash], but had little effect on other components of the herbaceous vegetation. Abundance of curlymesquite increased substantially following applications of tebuthiuron, at the expense of annual and short-lived perennial grasses and herbaceous broadleaf species.

Glyphosate [N-(phosphonomethyl)glycine] applied at 1.1 kg/ha to wheat [Triticum aestivum (L.) ‘Arthur 71′] plants increased height and fresh weight of soybean [Glycine max (L.) Merr. ‘Ransom′] seedlings planted in the pot at time of application of the glyphosate as the number of wheat plants treated increased from 5 to 30/pot. Height and fresh weight of the soybean seedlings also increased as the rate of glyphosate applied to wheat plants (5/pot) increased from 1.1 to 6.7 kg/ha. Increasing the rate of glyphosate from 1.1 to 6.7 kg/ha, however, reduced the height and fresh weight of soybeans when 30 wheat plants/pot were treated. In addition, when 6.7 kg/ha of glyphosate were applied to wheat plants, soybean-seedling plant height and fresh weight decreased as the density of wheat plants per pot increased from 5 to 30. The 14C-glyphosate exuded into the soil from treated wheat plants was characterized by thin-layer chromatography. Trace amounts of the radio-label were present on thin-layer plates of leaf and stem extracts of corn (Zea mays L.) plants, which were growing in the same pots with the treated wheat plants. The zone of activity had the same Rf value as the glyphosate standard.

Of 15 hard red winter wheat (Triticum aestivum L.) cultivars grown on several soil types and treated in the spring with several rates of metribuzin [4-amino-6-tert-butyl-3-(methylthio)-as-triazine-5(4H)-one], ‘Lindon’ and ‘Vona’ were the most sensitive and ‘TAM W 101’ and ‘Osage’ the most tolerant. Differences in cultivar response to metribuzin occurred in 9 of 13 locations, but were not observed when precipitation was very light or when the soil was saturated at the time of treatment. TAM W 101 was also more tolerant than Vona in the greenhouse.

We are meeting near the Boston Common, an historic 50-acre public park that was set aside in 1630 for “common use as a cow pasture and training field.” Records show that 100 people (pirates, Indians, Quakers, and suspected witches) were hanged on the Common by the early Puritans who established the Massachusetts colony.

There were no farmers or scientists on this list. Hopefully, after this presentation, my name will not be added to the Puritans' “hit” list.

In tobacco (Nicotiana tabacum L. 'Speight G-28′) exposed to benefin (N-butyl-N-ethyl-α,α,α-trifluoro-2,6-dinitro-p-toluidine) vapors from treated soil, the leaves formed after treatment were shortened, narrowed, distorted in shape, and had an abnormal vein pattern. The leaves that had developed before treatment did not have these symptoms. More leaves developed on treated than on untreated plants. The height of treated plants was reduced and many axillary buds became active prematurely. The injured leaves, in general, had fewer epidermal cells, stomata, and trichomes per unit surface area; a smaller volume of intercellular space; and were thicker than those of untreated plants. Many of the meristematic cells in the leaf primordia and shoot apex of treated plants contained large and distorted nuclei and were oriented in improper planes. The plate meristems established by activity of the marginal meristems gave rise to a mass of undifferentiating parenchyma cells in the mesophyll of the young leaves. There was little formation of the palisade or spongy mesophyll layers, but enlargement of the undifferentiating cells caused a radial expansion of the lamina.

The persistence of alachlor [2-chloro-2′,6′-diethyl-N-(methoxymethyl) acetanilide], metolachlor [2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl)acetamide], and propachlor (2-chloro-N-isopropylacetanilide) in soil was examined under laboratory and field conditions using sorghum (Sorghum vulgare Pers. ‘NB280S′) or annual ryegrass (Lolium multiflorum Lam.) as bioassay species. In laboratory studies, degradation rate of alachlor and propachlor was greater at 50 and 80% than at 20% field capacity at 20 C. Degradation of metolachlor was greater at 80 than at 20% field capacity. Degradation rate of alachlor and metolachlor at 50% field capacity was greater at higher temperatures. Propachlor degradation rate varied with temperature. Under irrigated, cropped field conditions, the order of persistence was metolachlor > alachlor > > propachlor.

Perfluidone {1,1,1-trifluoro-N-[2-methyl-4-(phenylsulfonyl)phenyl] methanesulfonamide} controlled wild Allium species when applied in the fall, winter, or early spring after the plants had emerged in bermudagrass [Cynodon dactylon (L.) Pers.] and zoysia (Zoysia spp.) turf. A single 3.4- or 4.5-kg/ha rate generally resulted in good to excellent control, but repeated treatments for 2 consecutive yr were required to obtain consistent control.

An experiment was established in 1961 to determine the influence of bearmat (Chamaebatia foliolosa Benth.) competition on ponderosa pine (Pinus ponderosa Laws.) survival and growth. Ponderosa pine seedlings were planted in bearmat which was: (A) untreated, (B) sprayed with a mixture of 2,4-D [(2,4-dichlorophenoxy)acetic acid] and 2,4,5-T [(2,4,5-trichlorophenoxy)acetic acid], and (C) eliminated by a combination of herbicide, clipping sprouts, and trenching to prevent root and rhizome invasion. Ponderosa pine survival after 19 yr averaged 9%, 66%, and 90%, respectively, for the three treatments. Tree height after 19 yr averaged 1.6, 1.9, and 5.7 m for treatments A, B, and C, respectively. Soil moisture use was initially less on the herbicide-treated than on the untreated plots, but bearmat quickly sprouted after application to compete with the pine seedlings for moisture. After 19 yr the bearmat was more dense and appeared to be more vigorous on the sprayed plots than on those receiving no treatment. We estimate that 75% reduction in net wood production could result after 50 yr on this site from bearmat competition.

Chemical herbicides are without question the most effective immediate solution to most weed problems. They are not, however, the only option or necessarily the best for all weed control situations (23, 24, 34). Recent commercialization of two biological herbicides illustrates another weed control technology with potential (24, 27, 44, 50). Abbott Laboratories marketed the fungus Phytophthora palmivora Butler in 1981 for control of strangler vine (Morrenia odorata Lindl.) in Florida citrus groves. The Upjohn Company will market the fungus (Colletotrichum gloeosporioides f. sp. aeschynomene (c.g.a.) in 1982 for control of northern jointvetch [Aeschynomene virginica (L.) B.S.P.] in Arkansas rice (Oryza sativa L.) and soybean [Glycine max (L.) Merr.] fields (45).

Oat (Avena sativa L. ‘Elgin′) seedlings were treated with combinations of diclofop-methyl {methyl ester of 2-[4-(2,4-dichlorophenoxy)phenoxy] propanoic acid} and 2,4-D amine [dimethylamine salt of (2,4-dichlorophenoxy) acetic acid] or diclofop-methyl and chlorsulfuron {2-chloro-N-[[(4-methoxy-6-methyl-1, 3, 5-triazin-2-yl)amino] carbonyl] benzenesulfonamide} to determine the effect of the added herbicide on diclofop-methyl activity. Diclofop-methyl applied alone at rates of 0.50, 0.75, and 1.00 kg/ha killed the oat plants 14 days after treatment. When 2,4-D amine at 0.74 and 1.11 kg/ha was combined with diclofop-methyl, the phytotoxicity of diclofop-methyl was reduced. An antagonistic interaction between diclofop-methyl and 2,4-D was detected. Chlorsulfuron, applied alone, at 20, 40, or 60 g/ha did not affect the growth of oats. Chlorsulfuron additions did not affect the activity of diclofop-methyl. Diclofop-methyl reduced oat coleoptile elongation. Equimolar concentrations of diclofop-methyl and 2,4-D at or above 1 μM significantly reduced the 2,4-D response. A ten-fold increase of either 2,4-D or diclofop-methyl, above an equimolar concentration of 1 μM, significantly enhanced the effect of the herbicide being increased.

DCPA (dimethyl tetrachloroterephthalate), bensulide [O,O-diisopropyl phosphorodithioate S-ester with N-(2-mercaptoethyl)benzenesulfonamide], and oxadiazon [2-tert-butyl-4(2,4-dichloro-5-isopropoxyphenyl)-Δ2-1,3,4-oxadiazolin-5-one] were applied to bermudagrass [Cynodon dactylon (L.) Pers. ‘Common′] as consecutive repeated annual treatments or in all possible sequence combinations for 3 yr to determine the effects on species composition of winter and summer annual weeds. Regardless of the rotation of treatments on winter weeds, oxadiazon increased the cover of common chickweed [Stellaria media (L.) Cyrillo], spur weed (Soliva spp.), and thymeleaf sandwort (Arenaria serpyllifolia L.); bensulide increased the cover of corn speedwell (Veronica arvensis L.); and DCPA in most instances increased the cover of hop clover (Trifolium agrarium L.) and spur weed. When a herbicide controlled large crabgrass [Digitaria sanguinalis (L.) Scop.] or goosegrass (Eleusine indica L. Gaertn.), the cover of weeds not controlled increased rapidly, with the exception of oxadiazon applied for 3 consecutive yr.