The influence of manure and herbicide applications on weed-free fieldbeans (Phaseolus vulgaris L.) and root rot of fieldbeans was studied during 1978 and 1979 at Scottsbluff, Nebraska. Rates of cattle feedlot manure used were 0, 30000, 56000, 112000, or 168000 kg/ha. Preplant herbicide treatments used were alachlor [2-chloro-2′6′-diethyl-N-(methoxymethyl)acetanilide] at 3.4 kg/ha, EPTC (S-ethyl dipropylthiocarbamate) at 3.4 kg/ha, EPTC + trifluralin (α,α,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine) at 2.2 + 0.6 kg/ha, or dinoseb (2-sec-butyl-4,6-dinitrophenol) at 6.7 kg/ha. Manure rates of 56000 kg/ha or higher reduced fieldbean yields both years, but did not increase electrical conductivity or soil exchangeable sodium enough to explain these yield reductions. In 1978, but not in 1979, height and yield of weed-free fieldbeans were reduced by EPTC, EPTC + trifluralin, and alachlor treatments. A significant interaction between manure and herbicide treatments was not detected and none of the treatments increased the severity of root rot in either year.

Since the aerial brush control spraying operations in northern Minnesota have little research basis, the Lake States Forest Experiment Station has been carrying on some fundamental.studies aimed at improving the results of this increasingly important aid to forest management. These consist of analyzing two factors basic to all foliage spraying jobs whether they are done from the air or from the ground. These are:

1. The minimum amount of herbicide (in terms of acid equivalent) required to control a unit-area of brush of a given species and density, and

2. The minimum amount of solution needed to distribute the herbicide uniformly over the sprayed area.

Field plots of small well-rooted plants of yew [Taxus media Rehd., var. Hicks] and maple [Acer palmatum Thunb., var. Japanese maple] were treated annually for 3 years with 3-(3,4-dichlorophenyl)-1,1-dimethylurea [diuron], 2-chloro-4,6-bis(ethylamino)-s-triazine [simazine], 2-(2,4-dichlorophenoxy)ethyl sodium sulfate [sesone], dimethyl tetrachloroterephthalate [DCPA], isopropyl m-chlorocarbanilate [chlorpropham], α,α,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine [trifluralin], 2-sec-butyl-4,6-dinitrophenol [dinoseb], and 3-amino-s-triazole [amitrole]. Commercial formulations of the herbicides were applied in water as a soil drench in May each year, at minimum effective dosage levels for weed control and at much higher levels. Diuron at herbicidally effective rates significantly reduced stand and growth of yew and maple plants. Simazine and sesone caused noticeable but variable reductions in growth of maple plants that were not statistically significant and yew plants were unaffected by these treatments. None of the other herbicides caused visible or measurable differences in growth.

Control of littleseed canarygrass (Phalaris minor Retz.), wild oat (Avena fatua L.), common lambsquarters (Chenopodium album L.), and field bindweed (Convolvulus arvensis L.) in dwarf wheat (Triticum aestivum L.) fields was studied with five herbicides and hand weeding. Terbutryn [2-(tert-butylamino)-4-(ethylamino)-6-(methylthio)-s-triazine] and 1-benzthiazol-2-yl-1,3-dimethylurea controlled the weeds more effectively than did two hand weedings. Diuron [3-(3,4-dichlorophenyl)-1,1-dimethylurea], nitrofen (2,4-dichlorophenyl p-nitrophenyl ether), and dichlormate (3,4-dichlorobenzyl methylcarbamate), proved only partially effective against weeds, and were therefore significantly inferior to two hand weedings. Spikes per meter of row length and test weight of wheat were increased significantly by 1-benzthiazol-2-yl-1,3-dimethylurea (1.5 to 2 kg/ha), terbutryn (0.5 kg/ha), and two hand weedings over the yields of the weedy check. The 1-benzthiazol-2-yl-1,3-dimethylurea showed a high degree of selectivity in the wheat crop at 2 kg/ha and increased yields to those of weed-free plots. Terbutryn was almost as effective as 1-benzthiazol-2-yl-1,3-dimethylurea, which increased the wheat yields over those of the weedy check by 19.8 and 42.4% during the 1974/75 and 1975/76 seasons, respectively. Tolerance of dwarf wheat to terbutryn at 0.75 kg/ha was variable, resulting in significant decreases in yield components and grain yield. Dry-matter yield of wheat was negatively correlated with the dry matter production of weeds.

The effects of chloride salts of potassium, sodium, ammonium, and lithium and abscisic acid (ABA) on the translocation of 2,4,5-T [(2,4,5-trichlorophenoxy)acetic acid] in bean (Phaseolus vulgaris L. Var. Stringless Green-pod) seedlings were determined. 14C-labeled 2,4,5-T was injected in the stem tissue at the cotyledonary node in a 1-μl volume along with ABA. The salts were added to the nutrient solution at 20 mM concentrations at the time of 2,4,5-T treatment. Sodium chloride inhibited 2,4,5-T accumulation in the upper portion of the plant; and except for LiCl, the salts tended to increase accumulation in the nutrient solution. LiCl increased 2,4,5-T accumulation in the young shoots and primary leaves and decreased accumulation in the roots and nutrient solution. The effects of ABA on 2,4,5-T translocation were similar to the effects of NaCl but were more pronounced. ABA caused large decreases in 2,4,5-T translocation to the young shoots and primary leaves and increased accumulation in the nutrient solution.

Yaupon (Ilex vomitoria Ait. ♯ ILEVO) in the Post Oak Savannah of Texas was treated with liquid and dry formulations of herbicides. Sprays of Bay Met 1486 {N-[5-(ethylsulfonyl)-1,3,4-thiadiazol-2-yl]-N, N′-dimethylurea} and picloram (4-amino-3,5,6-trichloropicolinic acid), sprays and pellets of tebuthiuron {N-[5-(1,1-dimethylethyl)-1,3,4-thiadiazol-2-yl]-N,N′-dimethylurea}, and boluses of hexazinone [3-cyclohexyl-6-(dimethylamino)-1-methyl-1,3,5-triazine-2,4(1N,3H)-dione] at 4.5 kg ae or ai/ha were the most effective treatments, reducing the canopy 87 to 99% and killing 68 to 93% of the yaupon after 2 yr. The percentage of dead yaupon after 1 yr was similar to that found 2 or 3 yr after treatment. Most herbicides, except clopyralid (3,6-dichloro-2-pyridinecarboxylic acid), reduced the yaupon canopy sufficiently to allow an increase in understory grass and broadleaf vegetation, particularly 1 yr after treatment.

The purpose here was to study fundamental aspects of polyphenoloxidase in dormant tubers.

Chlorpropham (isopropyl m-chlorocarbanilate) at 6.7 kg ai/ha controlled a mixture of field dodder (Cuscuta campestris Yunck. ♯3 CVCCA) and largeseed dodder (Cuscuta indecora Choisy ♯ CVCIN) for 3.0 and 4.3 weeks in two greenhouse experiments. The insecticide carbaryl (1-naphthyl N-methylcarbamate) at 0.8 kg ai/ha applied with chlorpropham extended control by 0.7 and 1.8 weeks, and PCMC (p-chlorphenyl N-methylcarbamate) at 0.8 kg ai/ha extended it by 2.7 and 2.8 weeks. Both additives also improved dodder control by chlorpropham in the field, with carbaryl having less effect than PCMC.

Promising results of applications of α, α-dichloropropionic acid (Dalapon) to wild oats (Avena fatua) were first reported in May 1953 in Dow Chemical Company's Dalapon Bulletin No. 1. Encouraging results with Dalapon on wild oats were obtained by various workers during the summer of 1953. The work reported herein was conducted in 1954 to gain further information on the effects of Dalapon on wild oats.

Fenac [(2,3,6-trichlorophenyl)acetic acid] and 4-amino-3,5,6-trichloropicolinic acid (picloram) at 28 and 2.2 kg/ha, respectively, controlled woollyleaf bursage (Franseria tomentosa Gray) for 3 years in noncropped areas. Effective control of woollyleaf bursage was obtained when treated at the bud stage or earlier with an ester formulation of (2,4-di= chlorophenoxy)acetic acid (2,4-D) at 2.2 kg/ha or 3-amino-s-triazole (amitrole) at 4.5 kg/ha in an oil-water emulsion carrier or 3,6-dichloro-o-anisic acid (dicamba) at 2.2 kg/ha in a water carrier with 0.5% surfactant. Picloram, at 0.44 kg/ha or more, controlled woollyleaf bursage at any time of application.

Spot-treatments of young cotton with 2,2–dichloropropionic acid, simulating control of clumps of perennial grass, resulting in 10 to 25% reductions in cotton stands, did not cause proportional reductions in yields of seed cotton. Increased growth of cotton plants adjacent to skips compensated for reduced stands. The treatments did not affect boll components or fiber properties of cotton.

Seeds of winged elm (Ulmus alata Michx.) stored under moist conditions lost viability rapidly. Under dry conditions the seeds lived longer. Winged elm seeds would not germinate at 4 C or 42 C but did at temperatures between these points. Salt concentrations above 20,000 ppm killed the seed; concentrations below this inhibited germination; twelve per cent manitol solutions (16 atmospheres osmotic pressure) prevented germination; pressures lower than this decreasingly affected germination. If the soil moisture level was below 2%, winged elm seeds would not germinate. Removal of the outer husk of the seed did not affect germination. Winged elm seedlings did not emerge if planted at depths below ¼ inch.

The effects of temperature and the annual growth cycle on the formation of root suckers were determined by propagating root cuttings of black locust (Robinia pseudoacacia L.). The percentage of cuttings which formed suckers in an air temperature of 60 F was significantly lower than that of cuttings at 70 to 80 F. In the annual growth cycle experiment, cuttings removed in June formed significantly fewer suckers than those removed during January, March, August, or November.

A model of the pharmacokinetics of atrazine [6-chloro-N-ethyl-N′-(1-methylethyl)-1,3,5-triazine-2,4-diamine] in barley (Hordeum vulgare L. ‘Escourgnon’) plants has been described. Uptake of atrazine conforms to a first-order kinetic model. Roots play a small role as a sink for atrazine. Metabolism of the herbicide conforms to a second-order kinetic model. Using this model, the amount of atrazine in leaves can be evaluated at any time if the concentration of herbicide in solution is known.

The effect of PBA, dalapon and amitrole applications on the osmotic pressure, electrical conductivity and pH of quackgrass rhizome sap and the total nitrogen and hygroscopic capacity of dried rhizomes, from May 17 through October 15, are reported. Characteristic seasonal curves were developed for all five specific factors studied. The herbicide treatments accentuated the variation in some of these factors but did not appreciably modify the seasonal curves.

Control of weeds growing around field edges to limit seed production is an important component of preventative weed management. POST herbicide rates that are effective on weeds growing within a dense corn or soybean canopy may not be high enough to control weeds at the edge of a field. A study was conducted from 2004 through 2006 to compare velvetleaf growth and fecundity at the edge of the field as opposed to within the crop in response to a range of glyphosate rates. Treatments included position (plot center or edge), time of emergence (VE or V4 crop growth stage) and glyphosate rate (0 to 900 g ae ha−1). Without herbicide application, velvetleaf plants grown on the edge flowered earlier, had thicker stems, and produced more seed capsules than plants grown in the center of the plots. At glyphosate application rates of 200 to 900 g ha−1, the percentage of plants surviving and reproducing was higher on the edge than within the crop. Edge plants treated with 900 g ha−1 of glyphosate produced more seeds than center plants that received no herbicide. Dose–response curves were used to estimate the glyphosate rate that would reduce seed production of surviving plants to 80% of the untreated plants. Plants emerging at the VE stage were estimated to require 300 g ha−1 within the corn or soybean canopy and 668 g ha−1 on the crop edge, whereas plants emerging at the V4 stage would require 0 g ha−1 within the canopy and 280 g ha−1 on the crop edge.

In a previous study Stadtherr and Widmer reported that several herbicides provided excellent weed control in field plantings of garden chrysanthemums (Chrysanthemum morifolium) The present study was undertaken (a) to compare the best herbicides of the previous study with newer materials, (b) to obtain additional data on herbicides which had been tested for one year only, and (c) to determine the effectiveness of herbicides applied in granular form.

Tank mixtures of herbicides for control of emerged winter weeds and preemergence control of large crabgrass [Digitaria sanguinalis (L.) Scop. # DIGSA] were evaluated on bermudagrass [Cynodon dactylon (L.) Pers. ‘Common’ # CYNDA] fairways over a 2-yr period. Glyphosate [N-(phosphonomethyl)glycine] applied at 0.28 kg ai/ha in tank mixtures with DCPA (dimethyl tetrachloroterephthate) at 11 kg ai/ha controlled a higher percentage of parsley-piert (Alchemilla microcarpa Boiss. Reut. # APHMI) than either herbicide alone. When applied for spur weed (Soliva spp.) control, DCPA was antagonistic in the tank mixture with simazine [2-chloro-4,6-bis(ethylamino)-s-txiazine]. During one yr of the 2-yr study period, control of large crabgrass was less in plots treated with combination of DCPA and glyphosate than in plots treated with DCPA alone. Less large crabgrass control was obtained in plots treated with bensulide [O,O-diisopropyl phosphorodithioate S-ester with N-(2-mercaptoethyl)benzenesulfonamide] at 11 kg ai/ha in combinations with either paraquat (1,1′-dimethyl-4,4′-bipyridinium ion) or 2,4-D [(2,4-dichlorophenoxy)acetic acid] plus mecoprop {2-[(4-chloro-o-tolyl)oxy]propionic acid} plus dicamba (3,6-dichloro-o-anisic acid) than when treated only with bensulide.