bluuebunny/crossref_metadata_2025 huggingface dataset:
Selective Weed Control in Sugarbeets
Authors: Eshel Y. , Sompolinsky D. , Cohen A.
Published: May 2019

Nine field trials were carried out during 1968 and 1969 to study selective weed control in sugarbeets(Beta vulgarisL.) by preemergence and postemergence applications. The trials were conducted at various regions of Israel, under a wide range of climatic and edaphic conditions. Among the preemergence treatments, the herbicide 1-methyl-3-(2-benzothiazolyl)-urea (hereinafter referred to as benzthiazuron) gave adequate weed control and selectivity to sugarbeets. However, when heavy infestation with grasses was present, an addition of isopropyl carbanilate (propham) was needed to increase the spectrum of weed control. A preemergence application of 1-butyl-3-(3,4-dichlorophenyl)-1-methylurea (neburon) on each side of the drill-row of sugarbeets together with an over-band application of benzthiazuron or 5-amino-4-chloro-2-phenyl-3(2H)-pyridazinone (pyrazon) improved weed control. Among postemergence treatments, a mixture of pyrazon and propham gave excellent broad-spectrum weed control. Applying this combination in an emulsion with a non-phytotoxic oil considerably improved weed control.
Anatomy of Purple Nutsedge
Authors: Wills G. D. , Briscoe George Ann
Published: May 2019

Purple nutsedge(Cyperus rotundus L.)develops as a series of shoots connected by bulbs, rhizomes, and tubers. The leaves contain parallel, collateral vascular bundles with the majority of the photosynthetic cells concentrated in the sheathing girdle around each bundle. The upper leaf surface consists of a single layer of large epidermal cells covered by a thick cuticle. Stomates occur only in the lower surface. The vascular bundles vary from collateral to amphivasal as they pass from the leaves through the bulb into the rhizomes and tubers. Newly developing rhizomes and tubers appear white and fleshy with a parenchymatous epidermis and cortex. Mature rhizomes appear brown and wiry with a deteriorated outer cortex and a lignified inner cortext and endodermis. Tubers and bulbs form similarly at the rhizome apices with each accumulating starch. The interconnecting vascular system appears to remain intact throughout the growing season.
Herbicide Performance in Flue-Cured Tobacco
Authors: Worsham A. D.
Published: May 2019

Weed control performance of several herbicides, their effects on tobacco(Nicotiana tabacumL.), and two methods of soil incorporation were studied in North Carolina in 1967 and 1968. Herbicides which gave acceptable weed control without injuring tobacco or lowering its quality were 4-(methylsulfonyl)-2,6-dinitro-N,Ndipropylaniline (nitralin),1,1,4-trimethyl-6-isopropyl-5-indanyl ethyl ketone (D-497), methyl ester of 3-amino-2,5-dichlorobenzoic acid (amiben),N-butyl-N-ethyl-α,α,α-trifluoro-2,6-dinitro-p-toluidine (benefin),S-propyl butylethylthiocarbamate (pebulate),S-propyl dipropylthiiocarbamate (vernolate),N,N-dimethyl-2,2-diphenylacetamide (diphenamid), dimethyl tetrachloroterephthalate (DCPA), 2,3,5-trichloro-4-pyridinol (pyriclor), and 2-(α-naphthoxy)-N,N-diethylpropionamide (R-7465). Soil incorporation of benefin, pebulate, and benefin + vernolate with a power-driven rotary cultivator gave superior weed control compared to incorporation by discing four times. Significant early-season stunting of tobacco plants was observed both years in plots where benefin (1.12 or 2.25 lb/A), benefin + vernolate (0.75 + 1.5 lb/A), or benefin + pebulate (1.12 + 4.0 lb/A) was incorporated by discing. No stunting was observed where incorporation was with the rotary cultivator except for benefin at 2.25 lb/A. Neither yield nor quality of the crop was reduced.
Uptake, Translocation, and Herbicidal Effect of Diphenamid
Authors: Deli J. , Warren G. F.
Published: May 2019

Root application ofN,N-dimethyl-2,2-diphenylacetamide (diphenamid) caused reduction of root and shoot growth of oats (Avena sativaL., var. Jaycee) seedlings. Shoot application did not affect plant growth, but studies with labeled diphenamid showed that diphenamid will enter also through the shoot. In ivyleaf morningglory (Ipomoea hederaceaL.), a considerable amount of label was translocated from the roots to the shoots, but not in oats seedlings. The difference in tolerance between these two species (oats susceptible, morningglory resistant) may lie in the ability of morningglory to translocate diphenamid out of the roots into the shoots faster than oats. The inhibitory effect of diphenamid was restricted to the site of uptake. Reduction in shoot growth of treated plants was the result of the limited root system and it was not a direct effect of diphenamid. Diphenamid was 10 times as toxic to oats as its metabolites. Oats seedlings inhibited by diphenamid for up to 5 days, and then placed in water recovered from the diphenamid caused inhibition. The resumed root growth appeared to be normal. The amount of uptake of14C-labeled sucrose by excised roots treated with 10−5M diphenamid was equal to that in untreated roots; however, more sugar was incorporated into the untreated roots than the treated roots. It appears that diphenamid is a reversible metabolic inhibitor; it inhibits cell division in the root tip perhaps by limiting utilization of substrates in the cells.
Effects of DCPA on Winter Injury of Recently-Established Bermudagrass
Authors: Fullerton T. M. , Murdoch C. L. , Spooner A. E. , Frans R. E.
Published: May 2019

The effect of dimethyl tetrachloroterephthalate (DCPA) applied during the establishment of Tifgreen bermudagrass (Cynodon dactylon(L.) Pers. XC. transvaalensisBurtt-Davy) on subsequent winter injury was studied. DCPA treatments to plots sprigged in July or later increased winter injury. DCPA applied in July, August, or September to plots planted in June resulted in approximately 15% of the turf being killed during the winter; however, DCPA applied before the middle of June did not significantly influence winter injury. Significant increases were found in total nitrogen, nitrate, amino acids, and protein of stolons harvested from DCPA-treated plots. These data suggest that DCPA treatments applied during establishment resulted in a less winter hardy condition by maintaining vegetative growth into the normal period of winter hardening.
A Technique to Assay Herbicide Translocation and Effect on Root Growth
Authors: Gentner W. A.
Published: May 2019

A split-stem technique was devised for the rapid evaluation of herbicide effect on root growth and herbicide translocation. Four rows of adventitious root initials were prominent on the stem of red kidney bean [Phaseolus vulgaris L.] seedlings. They were excised at the soil level above the vascular plate. Excised stems were longitudinally split for a distance of 75 to 90 mm leaving two rows of root initials on each stem portion. Split-stem halves were immersed in herbicide-nutrient and nutrient solutions, respectively, contained in paired 25 by 150-mm test tubes. Subsequent plant growth and development of treated plants reflected effects of the herbicide on root growth. Herbicide translocation often was indicated by abnormalities of growth of plant tissues remote from the herbicide solution.
Selectivity of Bromoxynil in a Resistant and a Susceptible Species
Authors: Schafer D. E. , Chilcote D. O.
Published: May 2019

The selectivity of 3,5-dibromo-4-hydroxybenzonitrile (bromoxynil) in winter wheat (Triticum aestivum L., var. Nugaines), a resistant species, and coast fiddleneck (Amsinckia intermedia Fisch. & Mey.), a susceptible species, was concluded to be the result of a complex of interactions. Wheat was 109 times more tolerant of bromoxynil than was coast fiddleneck. More spray solution was retained by coast fiddleneck plants than by wheat. Bromoxynil penetrated more rapidly into leaves of coast fiddleneck than of wheat. However, these factors did not fully explain bromoxynil selectivity. When differential spray retention and bromoxynil penetration was accounted for, it was estimated that coast fiddleneck was 30 times more susceptible than wheat.
Herbicides Applied as Liquid Sprays and Granules for Weed Control in Cotton
Authors: Robinson E. L. , Wooten O. B. , Williford J. R.
Published: May 2019

We evaluated the effectiveness of aqueous sprays and granules of 3-(3,4-dichlorophenyl)-1,1-dimethylurea (diuron), 1,1-dimethyl-3-(α,α,α-trifluoro-m-tolyl)urea (fluometuron), isopropylm-chlorocarbanilate (chlorpropham), α,α,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine (trifluralin), and 2-chloro-2′, 6′-diethyl-N-(methoxymethyl) acetanilide (alachlor) incorporated shallow for weed control in cotton(Gossypium hirsutumL., var. Stoneville 7A). In general, liquid formulation provided better weed control than did granular formulation. Applications of alachlor resulted in good weed control, but in a dry season the liquid spray form of the herbicide at high rates reduced the yield of cotton.
Flooding Tolerance of Fall Panicum and Texas Panicum
Authors: Hoveland C. S. , Buchanan G. A.
Published: May 2019

Fall panicum (Panicum dichotomiflorum Michx.) and Texas panicum (Panicum texanum Buckl.) were grown in the greenhouse under flooding treatments of 0, 6, and 9 days in 10 for 1 month. Fall panicum was more tolerant of flooded soil than was Texas panicum. Root development of Texas panicum was reduced by 50% under all flooding treatments. Herbage and root growth of fall panicum with flooding was similar to that on well-drained soil. Fall panicum root diameter was greater than that of Texas panicum, but both species increased under flooding. Tolerance of fall panicum to flooding may partially explain why it competes so well with crop plants during wet periods.
Stomata Variations in Canada Thistle and Response to Herbicides
Authors: Hodgson J. M. , Moore H. D.
Published: May 2019

Canada thistle(Cirsium arvense(L) Scop.) includes many regional races that are heritable, distinct ecotypes. When cultured at Bozeman, Montana a group of these ecotypes varied in phenological, morphological, and anatomical characteristics. These ecotypes also responded differently to (2,4-dichlorophenoxy)acetic acid (2,4-D) and 3-amino-s-triazole (amitrole). Stomatal frequency and area on leaves also differed among ecotypes studied. Although stomatal frequency and stomatal area differed among the ecotypes studied, there was no correlation with herbicide response. Apparently, stomata were not a significant portal of entry of 2,4-D into the upper surface of Canada thistle leaves.
Intraspecific Differential Response of Wild Oat and Barley to Barban
Authors: Jacobsohn Ruben , Andersen Robert N.
Published: May 2019

Two wild oat(Avena fatuaL.) biotypes and two barley(Hordeum vulgareL.) varieties known to have intraspecific differential response to foliarly-applied 4-chloro-2-butynylm-chlorocarbanilate (barban) were studied. When barban was applied to the roots, the intraspecific differential response (measured by shoot retardation) was maintained in both species but to a much lesser extent than previously observed with foliar application. Wild oat maintained a greater differential response than barley. Therefore, the factors causing the differential response to foliarly-applied barban may reside primarily in the leaves of both species but to some extent elsewhere (perhaps at the plant apex) in the wild oat biotypes and to a lesser extent elsewhere in the barley varieties. Differential response to foliar applications was not caused by differential uptake, but may be caused primarily by the susceptible biotype or variety's reduced ability to degrade barban beyond 3-chloroaniline. This might cause the greater build-up of compound X (a water-soluble 3-chloroaniline-containing metabolite of barban) observed in the susceptible biotype or variety. Compound X appeared to be nonphytotoxic. The build-up of compound X in turn may reduce the rate of metabolism of barban resulting in the greater amount of free barban found in the treated leaf of the susceptible biotype or variety 12 to 24 hr after treatment. This greater amount of free barban in the leaf of the susceptible biotype or variety may be responsible for the differential response to foliar applications of barban. Evidence for this partial explanation of the differential response was better for barley than for wild oat.
Interaction of Prometryne and Phorate on Bean
Authors: Parks John P. , Truelove Bryan , Buchanan Gale A.
Published: May 2019

The absorption by bean(Phaseolus vulgarisL. ‘Black Valentine’) of 2,4-bis-(isopropylamino)-6-(methylthio)-s-triazine (prometryne) at 1 μM concentration was increased in the presence of 10, 1, or 0.1 μMO,O-diethyl S-(ethylthio) methyl phosphorodithioate (phorate). An increase in absorption of 10 μM prometryne with addition of 1 μM phorate was recorded after 72 hr, but no increase was seen after 96 hr of absorption. Both prometryne and phorate inhibited state 3 respiration of mitochondria isolated from 6-day-old bean hypocotyls. Inhibition increased with increasing pesticide concentrations. When the pesticides were applied simultaneously, no interactions affecting state 3 respiration were observed. Neither prometryne nor phorate alone significantly affected phosphate accumulation by bean shoot mitochondria.
Persistence and Movement of Picloram in Two Kansas Soils
Authors: Phillips W. M. , Feltner K. C.
Published: May 2019

Persistence and movement of 4-amino-3,5,6-trichloropicolinic acid (picloram) were studied in silty clay loam soils located at Hays and Newton, Kansas. At Hays, picloram was applied to a Harney silty clay loam at rates of 2.24 and 3.36 kg/ha in 1963, 1964, 1965, 1966, and 1968 and at Newton to a Goessel (tentative) silty clay loam at rates of 1.12, 2.24, and 3.36 kg/ha in 1966. Fifteen, 20, or 30-cm increments of soil were taken from as deep at 2.4 m below the soil surface and bio-assayed with soybeans(Glycine max(L.) Merr. ‘Clark 63′) in 1968 and 1969. In both soils the highest concentration of phytotoxic residue remained near the soil surface, but differences between the two sites were evident. In the Goessel soil phytotoxic residues were detected only near the surface. In the Harney soil movement was uneven, but residues were detected as deep as 2.4 m below the surface. Soil cracks probably contributed to penetration of small amounts of the herbicide to as much as 2.4 m below the surface. Total picloram remaining in both soils diminished with time.
Absorption and Translocation of 2,4-DB in Soybean and Cocklebur
Authors: Wathana S. , Corbin F. T. , Waldrep T. W.
Published: May 2019

The absorption and translocation of 14C in 14C-ring-labelled 4-(2,4-dichlorophenoxy)butyric acid (2,4-DB) at 1 and 7 days after foliar treatment of soybean [Glycine max (L.) Merr.] and cocklebur (Xanthium sp.) were investigated at 3, 5, 7, and 11 weeks after planting by means of radioautography and standard radioassay methods. Partitioning of radioactivity varied with plant age and with treatment time. Although a species difference was not observed in the total uptake of 2,4-DB, the rate of penetration of the herbicide was greater in cocklebur than in soybean. The 2,4-DB was retained in the treated leaf and was not translocated to other plant parts. Translocated radioactivity occurred principally in actively growing parts of both species, but only trace quantities were detected in soybean. No radioactivity was detected in the lower leaves of either plant. Plant response to 2,4-DB may be partially explained on the basis of differential penetration and translocation.
Plant Cover Changes Following Herbicide Applications in Orchards
Authors: Schubert Oscar E.
Published: May 2019

Single applications of 4.48 and 22.4 kg/ha of the ester formulation of (2,4,5-trichlorophenoxy)acetic acid (2,4,5-T ester), 2,4,5-T amine, and 2-(2,4,5-trichlorophenoxy)propionic acid (silvex) to the ground cover and soil under apple(Malus sylvestrisMill.) trees significantly reduced the proportion of broadleaf plants to grasses. After six annual applications of these herbicides, the ground cover consisted of almost pure stands of grasses. Six applications of 2-sec-butyl-4,6-dinitrophenol (dinoseb) + oil at 4.2 kg/ha + 374 L/ha and five times this rate decreased the proportion of broadleaf weeds to grasses, but one application did not change the proportion. One and six annual applications of dinoseb amine at 16.8 and 84 kg/ha significantly reduced the percentage of broadleaf weeds. One application of 3-amino-s-triazole (amitrole) at 4.48 kg/ha and six annual applications of amitrole at 22.4 kg/ha significantly decreased the percentage of broadleaf weeds. Six annual applications of 2,2-dichloropropionic acid (dalapon) + dinoseb amine at 47.6 + 84 kg/ha significantly increased the percentage of broadleaf weeds, especially mouseear chickweed(Cerastium vulgatumL.) and red sorrel(Rumex acetosellaL.). Six annual applications of ammonium sulfamate (AMS) at 168 and 840 kg/ha increased the proportion of grasses to broadleaf weeds as did a single application at 168 kg/ha. AMS caused phytotoxic symptoms on young apple replants at the 168-kg/ha rate and also on mature trees at the 840-kg/ha rate. No phytotoxic symptoms were noted with the other herbicides applied.
Phytotoxicity of Trifluralin Vapors from Soil
Authors: Swann Charles W. , Behrens Richard
Published: May 2019

Foxtail millet [Setaria italica(L.) Beauv. ‘Empire’] and proso millet(Panicum miliaceumL. ‘White’) seedlings were grown in glass units to expose selectively either roots or shoots to vapors arising from soil containinga,a,a-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine (trifluralin). The root and shoot growth of both species was inhibited by trifluralin vapors. Suppression of root and shoot growth increased as trifluralin application rates increased. In shoot exposure, vapors arising from soil treated with 5 ppmw of trifluralin were lethal to seedlings of both species. In root exposure, root growth of both species was severely suppressed at 20 ppmw, but shoot growth was unaffected. Phytotoxic effects resulting from a given concentration of trifluralin were more severe as greater carrier volumes were used for application. Trifluralin vapors arising from soil 16 to 22 days after treatment were still sufficient to cause shoot growth inhibition.
Environment and Herbicide Effects on Canada Thistle Ecotypes
Authors: Hunter James H. , Smith Leon W.
Published: May 2019

Root sections of seven Canada thistle(Cirsium arvense(L.) Scop.) ecotypes were grown under 8, 12, 14, and 16-hr photoperiods at 16, 21, and 27 C. Flowering occurred in all ecotypes under a 16-hr photoperiod. At the 14-hr photoperiod five ecotypes flowered; flowering in three of them was temperature-dependent. Shoot and root development and plant height varied with ecotype. Both the root-to-shoot ratios and the number of shoot buds formed on the roots were inversely related to temperature and length of photoperiod. Herbicides tested for their effects on Canada thistle were 4-amino-3,5,6-trichloropicolinic acid (picloram), 3,6-dichloro-o-anisic acid (dicamba), and (2,4-dichlorophenoxy)acetic acid (2,4-D). Control of top growth increased with increasing temperature. Similarly, root control was maximum at 27 C, at which temperature there were few fleshy roots. Picloram, unlike 2,4-D and dicamba, caused little leaf damage but completely destroyed the root system.
Inheritance of Siduron Tolerance in Foxtail Barley
Authors: Schooler A. B. , Bell A. R. , Nalewaja John D.
Published: May 2019

Thirty-six collections of foxtail barley(Hordeum jubatumL.) from North Dakota, South Dakota, Minnesota, Wisconsin, and Montana varied in susceptibility to 1-(2-methylcyclohexyl)-3-phenylurea (siduron) as determined from radicle elongation of treated seeds. Data from F2seedlings of crosses between tolerant and susceptible selections indicated that three complementary dominant factors control the inheritance of siduron tolerance in foxtail barley. Evolution of siduron-tolerant foxtail barley could occur from selection pressure.
A Laboratory Spray Cabinet for Herbicides and Growth Regulators
Authors: Frank J. Ray , Creager Richard A. , Jacobs Lee M.
Published: May 2019

A laboratory spray cabinet was constructed of stainless steel with three compartments for separate dosage applications. Overhead spraying is accomplished in all three compartments by a single mobile nozzle activated by an air cylinder and cable drive. The system was designed so that test compounds could be applied safely and accurately at various rates on plants up to 1 m high. The cabinet has an air exchange and filtration system to prevent possible contamination of spray equipment, untreated test materials and the atmosphere.
Factors Affecting the Herbicidal Activity of TCA on Green Foxtail
Authors: Chow Paul N. P.
Published: May 2019

Growth of green foxtail (Setaria viridis (L.) Beauv.) was effectively controlled in the greenhouse by applying the sodium salt of trichloroacetic acid (TCA) as a postemergence treatment, when a rate of 0.84 kg/ha was used; when application preceded the two-leaf stage; and when 2.54 mm of water were available daily for moving TCA into the soil. There were significant interactions of TCA rate with light intensity, temperature, and source of seeds on the response of green foxtail. Seedhead production was curtailed at rates of 0.56 kg/ha or above when plants were grown under high light intensities (19,250 to 22,000 lux) and at moderate temperatures (20 to 22 C). Rates of 1.68 kg/ha or more were required to stop heading of foxtail grown at high temperature (27 C).
Factors Affecting Use of Activated Carbon to Improve Herbicide Selectivity
Authors: Burr R. J. , Lee W. O. , Appleby A. P.
Published: May 2019

Under greenhouse conditions activated carbon, applied as a slurry at the time of seeding, protected Italian ryegrass(Lolium multiflorumLam.) seedlings from the toxicity of 3-(3,4-dichlorophenyl)-1,1-dimethylurea (diuron) applied preemergence. Plants growing from seeds planted 1.3 cm deep received less protection from diuron than plants growing from seeds planted 0.6, 1.9, or 2.5 cm deep. Sandy loam soil required at least three times more activated carbon than a clay loam soil to obtain the same protection. Activated carbon applied at 130 kg/ha in a 2.5-cm band on the soil surface directly over the seeds provided adequate protection on a clay loam soil. On a sandy loam soil the 130-kg/ha rate was not adequate. Wetting agents added to aid in carbon wetting reduced the protective effect of activated carbon when added at 0.9 or 2.7% (v/v) but had only a slight effect on protection when added at 0.3% (v/v). The soil moisture level at the time of carbon application and the amount of subsequent irrigation did not influence the protection obtained with activated carbon.
The Antibiotic Effects of Plants in Laboratory and Field
Authors: Selleck G. W.
Published: May 2019

In laboratory experiments, plant extracts of small everlasting (Antennaria microphylla Rydb.), field pussytoes (A. neglecta Greene), and leafy spurge (Euphorbia esula L.) were toxic to germinating seeds. Extracts of small everlasting inhibited vegetative development of leafy spurge, and soil taken from the immediate vicinity of roots inhibited germination and radicle elongation of germinating seeds of some species. Small everlasting competes vigorously with leafy spurge, and this competition cannot be attributed to morphology and growth habit. It suppressed vegetative growth of leafy spurge from rhizome sections in which the two species were competing in pots. In field experiments, this shallow-rooted, lowgrowing plant exhibited a marked inhibition on the growth of the vigorous, deep-rooted perennial, leafy spurge, as did the soil in which small everlasting had been growing. Antibiotic competition appears to be significant with the Antennaria spp., and the paucity of forbs in patches of leafy spurge, even when bare ground is visible between shoots, suggests that this species also exerts antibiotic effects on other plants. Allelopathy is probably a significant influence in interspacial relationships of species in most plant communities. A fuller knowledge of these relationships and their causes could lead to the utilization of this phenomenon in weed control.
Establishment of Sericea Lespedeza
Authors: Hoveland C. S. , Buchanan G. A. , Donnelly E. D.
Published: May 2019

Sericea lespedeza (Lespedeza cuneata (Dumont) G. Don, var. Serala) was planted in three field experiments at three seeding rates with four rates of S-propyl dipropylthiocarbamate (vernolate). Grass and broadleaf weed populations were reduced, but sericea was unaffected by vernolate incorporated preplant. Use of a herbicide permitted a reduction in seeding rate with no decrease in sericea stand or forage yield. This treatment permitted harvesting a cutting of hay the establishment year with only a minor effect on production the next year. The beneficial effect of vernolate on sericea yield continued the second year, mainly because sericea plants were better established and more vigorous. Sericea seeding rate did not affect weed competition or forage yield. A seeding rate of 11 kg/ha with 3.4 kg/ha vernolate was the most practical treatment.
Response of Peanuts to Combinations of Herbicides with Other Pesticides
Authors: Cargill Roland L. , Santelmann P. W.
Published: May 2019

There were no apparent herbicide-insecticide or herbicide-fungicide interactions when two pesticides were used on peanuts (Arachis hypogaeaL.) in the greenhouse. In field studies, O,O-diethyls-(2-(ethylthio)-ethyl)-phosphorodithioate (disulfoton), O,O-diethyl s-((ethylthio)-methyl)-phosphorodithioate (phorate), 1,2-dibromo-3-chloropropane (dibromochloropropane), and pentachloronitrobenzene (PCNB) had little influence on phytotoxicity of the herbicides 3-amino-2,5-dichlorobenzoic acid (chloramben) andα,α,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine (trifluralin) to peanuts. There was no phytotoxic effect or yield reduction as a result of application of chloramben or trifluralin combined with the use of fungicide-treated seed in the field. However, in the greenhouse, top growth of the fungicide-treated checks was greater than that of the herbicide-fungicide seed treatments. Dibromochloropropane nematocide alone was injurious to peanut seedlings grown in the greenhouse, but the application of a herbicide did not increase the injury.
Volatility of Dichlobenil
Authors: Parochetti J. V. , Hein E. R. , Colby S. R.
Published: May 2019

Vapor losses of 2,6-dichlorobenzonitrile (dichlobenil) were studied under controlled laboratory conditions by trapping vapors directly in a magnesia silica absorbant. Vapor losses increased with increasing temperature. Herbicide loss from a spray formulation in 3 hr amounted to 10% at 30 C and 18% at 40 C. Volatility increased as the soil moisture level increased from air dryness to field capacity. However, as the moisture level was increased to saturation, vapor losses remained similar to losses at field capacity. Volatility from a granular formulation was reduced when compared to the spray application. Volatility decreased as the cation exchange capacity of the soils increased.
Shoot Zone Activity of Trifluralin and Nitralin
Authors: Barrentine W. L. , Warren G. F.
Published: May 2019

When localized treatments of α,α,α-trifluoro-2,6-di-nitro-N,N-dipropyl-p-toluidine (trifluralin) and 4-(methylsulfonyl)-2,6-dinitro-N,N-dipropylaniline (nitralin) were applied to the shoot zone of sorghum (Sorghum bicolor(L.) Moench, var. RS-610) and cucumber (Cucumis sativusL., var. Wis. SMR-15) before seedling emergence, the most susceptible sites were the sorghum coleoptilar node and the cucumber hypocotyl hook. The longer before emergence that the sorghum shoot was exposed to the herbicides, the greater was the injury. However, if herbicide concentration was sufficient, the growing point just above the sorghum coleoptilar node was inhibited by both herbicides when applied after seedling emergence. Maximum uptake of 14C-trifluralin and14C-nitralin occurred through the coleoptilar node and hypocotyI hook of sorghum and cucumber, respectively. Rate of entry, uptake, and translocation of 14C-trifluralin was greater than that of14C-nitralin in sorghum and cucumber shoots.
Selectivity of Nitrofen among Rape, Redroot Pigweed, and Green Foxtail
Authors: Hawton D. , Stobbe E. H.
Published: May 2019

The selectivity of 2,4-dichlorophenylp-nitrophenyl ether (nitrofen) among rape (Brassica campestrisL., var. Echo) and two weed species, redroot pigweed (Amaranthus retroflexusL.) and green foxtail (Setaria viridis(L.) Beauv.), was determined quantitatively by a replicated dosage-response experiment. On an ED50basis, green foxtail and redroot pigweed were, respectively, 5.8 and 63.3 times more susceptible than rape. Selectivity was divided into three parameters; viz., differential spray retention, differential penetration, and differential effects within the plant. Differences in retention were measured with the use of a water-soluble dye, while differences in penetration were determined with14C-labelled nitrofen. Spray retention on green foxtail was 66% of that on the rape and 64% as much nitrofen penetrated redroot pigweed as penetrated rape. Under the conditions of these tests it was estimated that green foxtail and redroot pigweed were, respectively, 9 and 99 times more susceptible to nitrofen than was rape.
Effect of Picloram on Germination and Seedling Development of Four Species
Authors: Chang In-Kook , Foy Chester L.
Published: May 2019

Laboratory and greenhouse studies were conducted to determine the response of four plant species to 4-amino-3,5,6-trichloropicolinic acid (picloram). Germination of soybean (Glycine max(L.) Merr., var. Lee) seeds was inhibited, step-wise, by 10−8to 10−3M concentrations of picloram. Safflower (Carthamus tinctoriusL.) germination was inhibited at 10−3M; however, radish (Raphanus sativusL.) and barley (Hordeum vulgareL.) were not affected by any concentration studied (10−6to 10−3M). Measurement of several parameters of growth such as fresh and dry weight, shoot height, number and dimensions of leaves, percent necrosis, hypocotyl or epicotyl length, and hypocotyl diameter revealed that picloram was both growth promotive and inhibitory to safflower, radish, and barley. Levels of picloram required for growth promotion or inhibition varied with the species, stage of plant growth, herbicide concentration, the specific tissue, and the parameter being measured. Typical malformations such as twisting of stems, death of growing points, and occurrence of callus growth (depending on the species and herbicide dosage) were observed in picloram-treated seedlings. Studies on water loss by evapotranspiration suggested that picloram caused a possible alteration of stomatal behavior and/or a disturbance of water metabolism in plants under appropriate conditions.
The Effect of 2-Chloroethylphosphonic Acid on Dicamba Translocation in Wild Garlic
Authors: Binning Larry K. , Penner Donald , Meggitt William F.
Published: May 2019

Foliar applications of 2-chloroethylphosphonic acid (CEPA) 7 days prior to spot applications of14C-labelled 3,6-dichloro-o-anisic acid (dicamba) to leaves of wild garlic (Allium vinealeL.) increased basipetal translocation of the dicamba as measured 7 days after dicamba treatment. High concentrations of CEPA were inhibitory. The ethylene released from CEPA degradation may have altered the metabolic “sink-source” relationships within the wild garlic plants allowing increased basipetal translocation of subsequent applications of dicamba when low concentrations of CEPA were applied.
Activated Carbon-Vermiculite Mixture for Increasing Herbicide Selectivity
Authors: Kratky B. A. , Warren G. F.
Published: May 2019

A mixture of activated carbon and vermiculite was used to increase the tolerance to 2-chloro-4,6-bis(ethylamino)-s-triazine (simazine) of direct-seeded cucumbers (Cucumis sativusL., var. Wisconsin SMR-15) in greenhouse tests and direct-seeded tomatoes (Lycopersicum esculentumMill, var. Bouncer) in greenhouse and field (var. Heinz 1370) tests. The tolerance of cucumbers to dimethyl tetrachloroterephthalate (DCPA) and 4-(methylsulfonyl)-2,6-dini tro-N,N-dipropylaniline (nitralin) also was increased in field trials. When the mixture was placed in a hole (0.75 inch deep by 1 inch diam) over the crop seed to the level of the soil surface, preemergence herbicides were detoxified in the small area; and the crop plant was not injured. The herbicide remained active outside the small protected area. Also, a wafer consisting of an activated carbon-vermiculite mixture, fertilizer, and seed provided protection to direct-seeded crops.
Atrazine Uptake by Sudangrass, Sorghum, and Corn
Authors: Roeth F. W. , Lavy T. L.
Published: May 2019

The uptake of 2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine (atrazine) was studied in sudangrass [Sorghum sudanense(Piper) Stapf, var. Piper], grain sorghum [Sorghum bicolor(L.) Moench], and corn (Zea maysL.) to find whether differences in atrazine uptake exist among these species. The uptake of atrazine followed closely the growth patterns of corn, sorghum, and sudangrass during the first 5 weeks of growth. Concentration of14C from ring-labeled14C-atrazine in the soil reached a peak in corn, sorghum, and sudangrass plants after 2 weeks of growth and then declined. The14C concentrations were two to three times greater in sorghum and sudangrass than in corn throughout the 5-week period. Atrazine uptake per gram of plant growth by these crops was directly proportional to the concentration of atrazine in the soil and the proportionality factors were in the order: sudangrass < sorghum ≫ corn. Total uptake and the total growth were in order: corn ≫ sorghum = sudangrass. In a study where relative humidity was a variable, the amount of atrazine absorbed per ml of water was inversely related to total water usage.
Dicamba Uptake, Translocation, Metabolism, and Selectivity
Authors: Chang F. Y. , Vanden Born W. H.
Published: May 2019

Greenhouse studies indicated that 3,6-dichloro-o-anisic acid (dicamba) or its metabolic derivative was strongly accumulated in meristematic tissues of Tartary buckwheat (Fagopyrum tataricum(L.) Gaertn.) and wild mustard (Sinapis arvensisL.) following both foliar and root uptake. In barley (Hordeum vulgareL.) and wheat (Triticum vulgareL.), it was distributed throughout the plants. Detoxification of dicamba occurred in all four species though not at equal rates, and a common major metabolite was identified chromatographically as 5-hydroxy-3,6-dichloro-o-anisic acid. A minor metabolite, 3,6-dichlorosalicylic acid, was found in barley and wheat but not in Tartary buckwheat or wild mustard. The four species tolerated dicamba treatment in the order of wheat, barley, wild mustard, and Tartary buckwheat. This ranking corresponds with the ability of the plants to detoxify dicamba and is inversely related to the extent of dicamba absorption and translocation in them.
Competition Between Sugarbeets and Five Densities of Kochia
Authors: Weatherspoon D. M. , Schweizer E. E.
Published: May 2019

In a 2-year study, five densities of kochia (Kochia scoparia(L.) Schrad.) competed with sugarbeets (Beta vulgarisL.) for the entire growing season. The yield of sugarbeet roots and pounds of sucrose per acre decreased as the intensity of competition from kochia plants increased. One kochia plant per 25 ft of row reduced the average yield of roots by 2.6 T/A and sucrose by 960 lb/A. A density of one kochia plant, or more, per 2 ft of row in the first year, or one kochia plant per 1 ft of row in the second year, significantly reduced the sucrose content of the roots. Individual kochia plants significantly reduced the weight of sugarbeet tops and roots within a radius of 31 inches from the center of the sugarbeet row.
Influence of GA on Uptake and Accumulation of Naptalam by Bean Plants
Authors: Devlin Robert M. , Yaklich Robert W.
Published: May 2019

Bean plants (Phaseolus vulgaris L. var. Black Valentine) pretreated with gibberellic acid (hereinafter referred to as GA) absorb and accumulate considerably more N-1-naphthylphthalamic acid (naptalam) than untreated plants. All concentrations of GA from 2.9 × 10−6 to 8.6 × 10−4M were effective; peak influence occurred at 6 × 10−4M. Plants pretreated with this concentration took up 58% more naptalam than untreated plants. When the different parts of the plant were analyzed for naptalam separately, the leaf area (on a per g dry weight basis) was influenced most by GA pretreatment. The leaf area of bean plants pretreated with 2.9 × 10−4M contained 212% more naptalam than the leaf area of untreated plants. The leaf area also included all stem and petiole tissue above and including the first true leaves.
Growth and Development of Johnsongrass Ecotypes
Authors: McWhorter C. G.
Published: May 2019

Studies were conducted on the growth and development of 55 morphologically distinct vegetative types of johnsongrass (Sorghum halepense(L.) Pers.) collected throughout the United States and from several foreign countries. Observations were made also on the growth of sorghum almum (Sorghum almumParodi) from three foreign countries. Mature leaf-blades of the different johnsongrass ecotypes varied in length from 31 to 59 cm and in width from 1.7 to 3.4 cm. Plant height and culm density varied 2 to 4-fold for the different ecotypes. Floret production varied from 87 to 352 sessile spikelets for representative panicles of the different ecotypes. The number and arrangement of branchlets within panicles also varied as did the size of various spikelet components. Sorghum almum produced much taller plants than did johnsongrass although culm density and lateral growth were less than that of johnsongrass.
Effects of Trifluralin and Organophosphorus Compounds on Cotton Seedlings
Authors: Hassawy Ghanem S. , Hamilton K. C.
Published: May 2019

Soil applications of α,α,α,-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine (trifluralin),O,O-diethylS-((ethylthio)methyl)-phosphorodithioate (phorate) and their combinations did not affect cotton (Gossypium hirsutumL.) germination. Plants grown on soil treated with trifluralin were shorter than plants on soil treated with phorate. High rates of phorate reduced shoot weights. Root weights of phorate-treated plants were higher than those of trifluralin-treated plants but lower than those of the controls. In culture solution and soil, trifluralin inhibited lateral roots of cotton. In the presence of phorate, trifluralin-treated plants produced more lateral roots than plants treated with trifluralin alone. Other organophosphorus compounds, when used in combination with trifluralin, did not increase the number of lateral roots.
Herbicide Combinations in Irrigated Cotton
Authors: Hamilton K. C. , Arle H. F.
Published: May 2019

Combinations of herbicides as single or separate applications to the soil were compared in furrow-irrigated cotton (Gossypium hirsutumL.). In seven tests, preplanting applications of four herbicides, primarily effective for grass control, were combined with postemergence applications of 3-(3,4-dichlorophenyl)-l,l-dimethylurea (diuron). Preplanting applications of 4-(methylsulfonyl)-2,6-dinitro-N,N-dipropylaniline (nitralin) andα,α,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine (trifluralin) before furrowing retarded growth of cotton and sometimes reduced stands. Herbicides applied after furrowing did not appear to affect cotton development. Combinations of the four herbicides with diuron gave satisfactory control of annual weeds until harvest. In 15 tests, preplanting applications ofO,O-diisopropyl phosphorodithioateS-ester withN-(2-mercaptoethyl) benzenesulfonamide (bensulide) were combined with preplanting or postemergence applications of four herbicides primarily effective for control of broadleaf weeds. Preplanting applications of 3-(p-chlorophenyl)-l,l-dimethylurea (monuron) usually caused temporary chlorosis and stunting of cotton seedlings. Postemergence applications of monuron and 2,4-bis(isopropylamino)-6-(methylthio)-s-triazine (prometryne) sometimes caused temporary chlorosis of cotton foliage. Combinations of herbicides controlled weeds until harvest in 14 of the 15 tests. There was no difference among the herbicide combinations in yield of cotton in 21 of the 22 tests. In the 15 tests sampled there were no differences in fiber properties and boll components among herbicide combinations.
Growth Characteristics of Common Milkweed
Authors: Jeffery Larry S. , Robison Laren R.
Published: May 2019

Seed dormancy of common milkweed (Asclepias syriaca L.) is broken by a few days of moist low-temperature after-ripening. The duration of low-temperature after-ripening of the seeds is temperature dependent. Seedling emergence is best when the seeds are planted 1 to 2 cm deep and extremely limited when planted 6 cm deep. Seedlings have the capacity to produce new shoots if clipped in the 1 to 1¾-leaf pair stage and multiple shoots if clipped in the 2 to 2½-leaf pair stage. All seedlings reaching the 4 to 4½-leaf pair stage before clipping produced new shoots.
Phenoxy Acid Herbicides for Barnyardgrass Control in Transplanted Rice
Authors: De Datta S. K. , Lacsina R. Q. , Seaman D. E.
Published: May 2019

In experiments conducted at the International Rice Research Institute, Philippines, all commonly marketed formulations and derivatives of either [(4-chloro-o-tolyl)oxy]acetic acid (MCPA) or (2,4-dichlorophenoxy) acetic acid (2,4,D) performed in about the same way and were equally safe for use in controlling barnyardgrass [Echinochloa crusgalli (L.) Beauv.] and other annual weeds in transplanted rice (Oryza sativa L.). Eleven-day-old rice seedlings were more susceptible to amine salts of 2,4-D or MCPA than 21-day-old seedlings. Granular formulations of some chemicals were relatively less toxic than liquid formulations. The toxic effect of spraying the potassium salt of MCPA was less prolonged on the indica variety, IR22, than it was on the japonica variety, Chianung 242, which had delayed flowering and maturity.
Herbicide Effectiveness, Soil Residues, and Phytotoxicity to Peach Trees
Authors: Skroch W. A. , Sheets T. J. , Smith J. W.
Published: May 2019

Dichlobenil (2,6-dichlorobenzonitrile), 3-tert-butyl-5-chloro-6-methyluracil (terbacil), and 3-tert-butyl-5-bromo-6-methyluracil (hereinafter referred to as DP-733) were applied annually for 3 years as soil surface or incorporated treatments for weed control in young peach (Prunus persica(L.) Batsch., var. Redhaven) trees. Average monthly ratings showed significant increases in bermudagrass (Cynodon dactylon(L.) Pers.) control with incorporation of all three herbicides. Treetrunk diameters in incorporated dichlobenil plots were greater than those in surface-applied dichlobenil plots. Incorporation in the soil reduced loss of dichlobenil, terbacil, and DP-733. The herbicides did not accumulate in the 0 to 15-cm soil layer. Low concentrations were detected in the 30 to 60-cm soil depth 1 year after the third annual application of 6.72 kg/ha of dichlobenil and 4.48 kg/ha of DP-733. Terbacil was not present in detectable amounts at 30 to 60 cm but was present in the 15 to 30-cm layer of 4.48 kg/ha plots.
Effects of IAA, Kinetin, and Trifluralin on Cotton Seedlings
Authors: Hassawy Ghanem S. , Hamilton K. C.
Published: May 2019

Trifluralin (α,α,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine), IAA (indoleacetic acid), kinetin (6-furfurylamino purine), and their combinations in culture solutions did not affect cotton (Gossypium hirsutumL., var. Deltapine Smooth Leaf) germination but reduced primary root and shoot lengths of seedlings. Trifluralin alone and in combination with IAA or kinetin inhibited lateral root development. When IAA and kinetin were both applied with 5 ppmw trifluralin, lateral roots developed.
Biological and Non-Biological Dissipation of Trifluralin from Soil
Authors: Messersmith C. G. , Burnside O. C. , Lavy T. L.
Published: May 2019

Phytotoxicity of α,α,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine (trifluralin), incubated for 10 months in Sharpsburg silty clay loam at 0.8 field capacity, remained a 6.4, 0, and 1.6 ppmw of the original 8 ppmw at 15, 25, and 35 C, respectively. In Anselmo sandy loam after 10-months incubation, trifluralin phytotoxicity remained at 3.0, 3.2, and 0.6 ppmw of the original 4 ppmw at 15, 25, and 35 C, respectively. Breakdown of 14C-trifluralin to 14CO2 in both soils was more rapid at 1.6 field capacity than at 0.8 field capacity, and at 1 ppmw than at 100 ppmw of trifluralin. Breakdown of 14C-trifluralin to 14CO2 accounted for 5 and 3% of the decrease of 14C-activity in Sharpsburg silty clay loam and Anselmo sandy loam, respectively.
Effect of Dicamba on RNA and Protein
Authors: Arnold W. E. , Nalewaja John D.
Published: May 2019

The effect of 3,6-dichloro-o-anisic acid (dicamba) was studied on wild buckwheat (Polygonum convolvulusL.) and wheat (Triticum aestivumL.) at two growth stages. Wild buckwheat, treated when 5 to 8 cm tall, was very susceptible to dicamba which caused rapid dehydration of the leaves and growth of callus tissue at stem internodes. Wild buckwheat, treated when flowering, increased in growth 2 days after treatment and then decreased after 4 days. Wheat growth tended to increase in all plant parts after treatment with dicamba at both the 2 to 3-leaf and the boot stages. Dicamba increased the RNA and protein content in wild buckwheat at both growth stages and in wheat at the boot stage. Dicamba affected the transition temperature and precipitation of reconstituted nucleohistone but not the uncombined nucleic acid or histonein vitro, indicating that a DNA-histone-dicamba complex had occurred. The binding of dicamba to protein varied with different proteins and reduced the UV absorbance of the bound proteins.
Uptake and Translocation of Selected Herbicides in Mugwort
Authors: Rogerson A. B. , Bingham S. W.
Published: May 2019

Four 14C-labeled herbicide solutions were used to determine uptake and translocation patterns in mugwort (Artemisia vulgaris L.) roots. The 14C-(2,3,6-trichlorophenyl)acetic acid (14C-fenac) was bound in the roots and rhizomes and structures initiated on the rhizomes were heavily labeled. Little movement of 14C-isomers of fenac or 14C-fenac occurred from point of application on leaves. Rhizomes devoid of roots did not offer an appreciable avenue for entry of 2-chloro-4,6-bis-(ethylamino)-s-triazine (14C-simazine) into mugwort. Little movement of 3-amino-s-triazole (14C-amitrole) occurred from primary to secondary plants. Uptake of 14C-fenac was not increased appreciably by pretreatment of the plant root-rhizome system with (2,4-dichlorophenoxy)acetic acid (2,4-D), 2,4-dinitrophenol (DNP), or simazine.
Response of Cotton to Combinations of Herbicides and Disulfoton
Authors: Ivy H. W.
Published: May 2019

A 3-year field experiment was initiated in 1967 to study the effects of herbicides in combination with the systemic insecticide,O,O-diethylS-2-[(ethylthio)ethyl] phosphorodithioate (disulfoton) on cotton (Gossypium hirsutumL.). Herbicide treatments of 3-(3,4-dichlorophenyl)-1,1-dimethylurea (diuron), 1,1-dimethyl-3-(α,α,α,-trifluoro-m-tolyl)urea (fluometuron), 3-(hexahydro-4,7-methanoindan-5-yl)-1,1-dimethylurea (norea), 4-(methylsulfonyl)-2,6-dinitro-N,N-dipropylaniline (nitralin), and α,α,α,-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine (trifluralin) did not significantly affect yield of weed-free cotton while disulfoton treatment significantly increased yield over the 3-year period. Yield with disulfoton was negatively correlated with number of thrips (Thripidaesp.). No interaction occurred between herbicides and disulfoton on yield, and only in 1 year was there an effect on stand.
Influence of Light and Sucrose onN-Glucosyl Pyrazon Formation in Red Beet
Authors: Stephenson G. R. , Dilley D. R. , Ries S. K.
Published: May 2019

The conversion of 5-amino-4-chloro-2-phenyl-3(2H)-pyridazinone (pyrazon) toN-chloro-4-phenyl-3(2H)-pyridazinone glucosamine (hereinafter referred to asN-glucosyl pyrazon) in intact seedlings and in leaf discs of red beets (Beta vulgarisL., var. Detroit Dark Red) was significantly greater in the light than in the dark. Pyrazon conjugation with glucose was dependent on the carbohydrate status of the leaf tissue, since the formation of theN-glucoside in the dark was further reduced with dark pretreatment but could be restored to the level observed in the light by infiltrating the leaf discs with supplemental sucrose.