Application of Herbicides in Foam

Weed Science ◽  
1970 ◽  
Vol 18 (4) ◽  
pp. 500-505 ◽  
Author(s):  
C. G. McWhorter ◽  
W. L. Barrentine
Keyword(s):  
Glycine Max ◽  
Gossypium Hirsutum ◽  
Weed Control ◽  
Field Conditions ◽  
Laboratory Studies ◽  
Water Sprays ◽  
Foam Production

We constructed a foam applicator capable of creating 300 to 400 gal of foam from 1 gal of water. The equipment was successful for applying herbicides in cotton (Gossypium hirsutum L., var. Stoneville 213) and soybeans (Glycine max Merr., var. Lee) after emergence. Weed control was equal with applications in foam as compared to conventional applications in water sprays. Foam production was highly dependent on the type and concentration of surfactant used. Various additives increased foam persistence in laboratory studies. However, for maximum effectiveness under field conditions, additives are needed that are more effective in increasing foam persistence than the ones evaluated.

Influence of Placement of Charcoal on Protection of Cotton(Gossypium hirsutum)from Diuron

Weed Science ◽  
1978 ◽  
Vol 26 (3) ◽  
pp. 239-244 ◽  
Author(s):  
J. M. Chandler ◽  
O. B. Wooten ◽  
F. E. Fulgham
Keyword(s):  
Gossypium Hirsutum ◽  
Weed Control ◽  
Activated Charcoal ◽  
Optimum Combination ◽  
Field Conditions ◽  
Degree Of Protection ◽  
Crop Injury

The effectiveness of activated charcoal in protecting seedling cotton(Gossypium hirsutumL. ‘Stoneville 213’) from diuron [3-(3,4-dichlorophenyl)-1,1-dimethylurea] at 1.78 and 3.55 kg/ha was investigated under field conditions over a 5-yr period. Charcoal did not provide adequate protection when applied through the seed hopper box or sprayed in the seed furrow over each hill. Charcoal at 83 and 167 kg/ha applied as a spot over each hill of cotton gave adequate protection. Shallow incorporation of the charcoal significantly reduced the degree of protection. The optimum combination, providing maximum weed control and minimum crop injury, was diuron at 3.55 kg/ha applied over non-incorporated charcoal at 83 kg/ha.

Biological Control of Northern Jointvetch in Rice by An Endemic Fungal Disease

Weed Science ◽  
1973 ◽  
Vol 21 (4) ◽  
pp. 303-307 ◽  
Author(s):  
J. T. Daniel ◽  
G. E. Templeton ◽  
R. J. Smith ◽  
W. T. Fox
Keyword(s):  
Biological Control ◽  
Oryza Sativa ◽  
Glycine Max ◽  
Gossypium Hirsutum ◽  
Incubation Period ◽  
Colletotrichum Gloeosporioides ◽  
Vegetable Crops ◽  
Liquid Media ◽  
Water Sprays ◽  
Common Field

An endemic anthrocnose disease of northern jointvetch [Aeschynomene virginica(L.) B.S.P.] incited by the fungusColletotrichum gloeosporioides(Penz.) Sacc. f. sp.aeschynomenewas discovered in 1969 at Stuttgart, Arkansas. When grown on solid or in liquid media, the organism grew rapidly and sporulated abundantly. From 1970 through 1972 water sprays of the fungus spores at 2 to 15 million spores per milliliter in 94 to 374 L/ha controlled northern jointvetch grown in the growth chamber, greenhouse, and field. The fungus controlled plants ranging from 5 to 66 cm tall. The disease developed on northern jointvetch most rapidly at temperatures of 23 to 32 C and at relative humidities above 80%. An incubation period of 4 to 7 days and up to 5 weeks was usually required to kill the weeds. The fungus was specific forAeschynomenespecies since it was very virulent onA. virginicaand only slightly virulent on Indian jointvetch (A. indicaL.). It did not affect rice (Oryza sativaL.), soybeans [Glycine max(L.) Merr.], cotton (Gossypium hirsutumL.), or 12 other common field, forage, and vegetable crops or 15 common weeds.

Rotation and Continuous use of Dietholate, Fonofos, and SC-0058 on EPTC Persistence in Soil

Weed Science ◽  
1990 ◽  
Vol 38 (2) ◽  
pp. 179-185
Author(s):  
Brent W. Bean ◽  
Fred W. Roeth ◽  
Alex R. Martin ◽  
Robert G. Wilson
Keyword(s):  
Weed Control ◽  
Inhibitory Influence ◽  
Laboratory Studies ◽  
Initial Development ◽  
Enhanced Biodegradation ◽  
Previously Treated ◽  
Repeated Use ◽  
Continuous Use ◽  
Biodegradation In Soil

Field and laboratory studies were conducted to examine the influence of continuous use and rotation of extenders on EPTC persistence in soils from Clay Center and Scottsbluff, NE. Rotation of EPTC + dietholate and EPTC + fonofos in soils with three prior annual treatments of each combination did not improve weed control compared to continuous use. SC-0058 was generally effective in slowing EPTC biodegradation in soils previously treated with EPTC, EPTC + dietholate, EPTC + fonofos, or EPTC + SC-0058. Dietholate was effective in slowing EPTC biodegradation in soil previously treated with EPTC or EPTC + SC-0058. SC-0058 appeared to have an inhibitory influence on the initial development of soil-enhanced EPTC biodegradation. Any enhanced biodegradation of dietholate or SC-0058 that may occur after repeated use was not a factor in enhanced EPTC degradation in EPTC + extender history soils.

Weed Control with Reduced Rates of Chlorimuron Plus Metribuzin and Imazethapyr in No-Till Narrow-Row Soybean (Glycine max)

1998 ◽  
Vol 12 (1) ◽  
pp. 32-36 ◽  
Author(s):  
William G. Johnson ◽  
Jeffrey S. Dilbeck ◽  
Michael S. Defelice ◽  
J. Andrew Kendig
Keyword(s):  
Glycine Max ◽  
Weed Control ◽  
Field Studies ◽  
Weed Suppression ◽  
Crop Response ◽  
Soybean Production ◽  
No Till ◽  
Giant Foxtail ◽  
The Difference ◽  
Narrow Row

Field studies were conducted at three locations in 1993 and 1994 to evaluate weed control and crop response to combinations of glyphosate, metolachlor, 0.5 X and 1 X label rates of chlorimuron plus metribuzin applied prior to planting (PP), and 0.5 X and 1 X label rates of imazethapyr applied early postemergence (EPOST) or postemergence (POST) in no-till narrow-row soybean production. Giant foxtail densities were reduced with sequential PP followed by (fb) EPOST or POST treatments. Large crabgrass was reduced equivalently with all herbicide combinations involving chlorimuron plus metribuzin PP fb imazethapyr. Common cocklebur control was variable but was usually greater with treatments that included imazethapyr. Ivyleaf morningglory densities were not reduced with any herbicide combinations. Sequential PP fb EPOST or POST treatments tended to provide slightly better weed suppression than PP-only treatments, but the difference was rarely significant. Soybean yields with treatments utilizing 0.5 X rates were usually equal to 1 X rates.

scholarly journals Influence of Flower Thrips on Fusarium Hardlock Severity

Plant Disease ◽  
2007 ◽  
Vol 91 (11) ◽  
pp. 1423-1429 ◽  
Author(s):  
D. J. Mailhot ◽  
J. J. Marois ◽  
D. L. Wright
Keyword(s):  
Gossypium Hirsutum ◽  
Untreated Control ◽  
Yield Loss ◽  
Fusarium Verticillioides ◽  
Field Conditions ◽  
Control Group ◽  
Flower Thrips ◽  
The Impact ◽  
Field Plots

Cotton (Gossypium hirsutum) fiber is sometimes affected by hardlock, which is characterized by a failure of the fiber to expand outward from the boll at maturity. Because affected fiber is inaccessible to mechanical harvesters, yield loss can be considerable. Hardlock has been linked to infection by Fusarium verticillioides. The involvement of flower thrips (Frankliniella spp.), which are commonly found in cotton flowers, was explored. At 1100 h, approximately 10% of cotton flowers contained thrips that were carrying F. verticillioides. The effect of thrips and/or Fusarium in flowers and bolls was explored under greenhouse conditions. Exposing flowers to Fusarium and thrips resulted in bolls with the most severe symptoms. Exposure to either Fusarium or thrips alone resulted in more hardlock than was noted in the control group. The impact of thrips was also evaluated under field conditions. Field plots were treated with insecticides, a fungicide, both, or left untreated. Insecticides reduced thrips numbers and reduced hardlock severity. The fungicide had no impact on thrips numbers and was less effective at reducing hardlock. Combining insecticide and fungicide applications was no more effective than using insecticides alone, although it more frequently increased yield. The untreated control plots generally had the most severe hardlock and lowest yields. Reducing hardlock severity resulted in higher yields, although not consistently. These studies suggest that thrips increase the severity of hardlock, and reducing their numbers may diminish hardlock severity.

Evaluation of Imazethapyr for Weed Control in Leafy Vegetable Crops

1996 ◽  
Vol 10 (2) ◽  
pp. 253-257 ◽  
Author(s):  
Joan A. Dusky ◽  
William M. Stall
Keyword(s):  
Regression Analysis ◽  
Weed Control ◽  
Crop Yield ◽  
Relative Sensitivity ◽  
Leafy Vegetable ◽  
Field Conditions ◽  
Vegetable Crops ◽  
Weed Species ◽  
Common Lambsquarters ◽  
Common Purslane

Imazethapyr was evaluated PRE and POST in five lettuce types and chicory under Florida field conditions. The relative sensitivity of leafy crop vigor (most sensitive to most tolerant) to imazethapyr PRE, based on 20% inhibition determined using regression analysis, was as follows: Boston > bibb > crisphead > romaine > leaf > escarole > endive. Leafy crop injury increased as the rate of imazethapyr applied POST increased, with all leafy crops responding in a similar manner. Surfactant addition increased imazethapyr phytotoxicity. Imazethapyr PRE treatments at 0.067 kg ai/ha provided greater than 80% control of livid amaranth, common purslane, flatsedge, and common lambsquarters. Imazethapyr POST at 0.067 kg/ha, with surfactant provided control greater than 85% of all weed species. Greater than 85% spiny amaranth control was provided by imazethapyr POST at 0.017 kg/ha. Use of surfactant with imazethapyr did not improve spiny amaranth control over imazethapyr with no surfactant. POST treatments did not decrease leafy crop yield compared with the hand-weeded check. Imazethapyr applied PRE reduced crop yield compared to the POST treatments and the hand-weeded control.

Effect of herbicides on the weed infestation and grain yield of soybean (Glycine max)

2004 ◽  
Vol 52 (2) ◽  
pp. 199-203 ◽  
Author(s):  
G. Singh ◽  
R. S. Jolly
Keyword(s):  
Glycine Max ◽  
Grain Yield ◽  
Weed Control ◽  
Negative Correlation ◽  
Rainy Season ◽  
Dry Matter ◽  
Field Experiments ◽  
Sand Soil ◽  
Loamy Sand Soil ◽  
Weed Infestation

Two field experiments were conducted during the kharif (rainy) season of 1999 and 2000 on a loamy sand soil to study the effect of various pre- and post-emergence herbicides on the weed infestation and grain yield of soybean. The presence of weeds in the weedy control plots resulted in 58.8 and 58.1% reduction in the grain yield in the two years compared to two hand weedings (HW) at 30 and 45 days after sowing (DAS), which gave grain yields of 1326 and 2029 kg ha-1. None of the herbicides was significantly superior to the two hand weedings treatment in influencing the grain yield. However, the pre-emergence application of 0.75 kg ha-1 S-metolachlor, and 0.5 kg ha-1 pendimethalin (pre-emergence) + HW 30 DAS were at par or numerically superior to this treatment. There was a good negative correlation between the weed dry matter at harvest and the grain yield of soybean, which showed that effective weed control is necessary for obtaining higher yields of soybean.

Herbicidal Concentrations of Picloram in Cell Culture and Leaf Buds

Weed Science ◽  
1972 ◽  
Vol 20 (2) ◽  
pp. 185-188 ◽  
Author(s):  
F. S. Davis ◽  
A. Villarreal ◽  
J. R. Baur ◽  
I. S. Goldstein
Keyword(s):  
Cell Culture ◽  
Glycine Max ◽  
Gossypium Hirsutum ◽  
Cell Cultures ◽  
Tolerance Limit ◽  
Primary Leaf ◽  
Fresh Weight ◽  
Internal Concentration ◽  
Order Of Magnitude

Cell cultures of soybean(Glycine max(L.) Merrill ‘Acme’) were exposed to media containing 4-amino-3,5,6-trichloropicolinic acid (picloram) for 15 days. Picloram also was supplied once in droplets (water) to cotyledons of 10 to 13-day-old seedlings of cotton(Gossypium hirsutumL. ‘Champion’). The amounts of picloram necessary to reach and exceed the 50% tolerance limit (TL50) of the cell cultures (inhibition) and of the primary leaf buds (toxicity) were established, and internal picloram concentrations then were determined. Internal concentrations at the TL50were 0.17 nM/g fresh weight and 14.7 nM/g fresh weight for cell cultures and leaf buds, respectively. These values are approximately 10−7and 10−5molar. In leaf buds, concentrations increased rapidly for 36 hr after treatment and declined slowly thereafter. Primary leaf buds accumulated up to several times the lethal internal concentration of picloram when the dosage to the cotyledons was increased by one order of magnitude.

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