Abstract
The influence offol iar applications of chloroxuron, chloroxuron plus surfactant, and 2, 4-DB on the response of soybeans and the control of cocklebur was studied underfield conditions in 1965 and 1 966 at two locations in South Carolina . Concurrent applications of each herbicide were made to soybeans with a natural cocklebur infestation to determine effective weed control and to determine response of soybeans when free of weeds. Early season control of cocklebur, within the limits of crop injury tolerance, was achieved using 4. 0 lb. / A chloroxuron or chloroxur on plus surfactant at 0. 5 to 1. 0 lb. / A applied when weeds were 2 to 3 inches tall. When weeds were growing under conditions of low soil moisture, more chloroxur on was required to achieve effective weed control. Chloroxur on and chloroxuron plus surfactant did not reduce soybean yields when applied to soybeans growing free of weeds. A 0. 2 lb . I A r ate of 2 , 4-DB applie d at mid-bloom stage of soybean development effectively controlled cocklebur; however , weed competition had by then prevailed throughout most of the growing season. Where the higher rates of 2 , 4-DB were applied on soybeans free of weeds , there was a trend toward lower yields, but the reduction in yield was not always significant. Prolonged weed competition and the risk of crop injury renders 2, 4-DB useful primarily as a salvage treatment to control cocklebur if early season control methods are ineffective . The effects of temperature and sunlight on the dissipation of soil surface-applied and soil-incorporated diuron, fluometuron, chloroxuron, and prometryne were studied in a series of field-growth chamber experiments conducted in 1966 and 1967. Bioassay responses relative to a standard bioassay were utilized to evaluate the amount of herbicidal dissipation. The loss of herbicidal effectiveness from the soil surface applied and sunlight-exposed treatments can be attributed in part to direct photodecomposition and to vaporization induced by soil surface temperatures of 120 to 130 F. Such losses would be of particular significance with chemicals applied during periods of prolonged hot, dry weather. Shallow incorporation generally proved effective in reducing herbicide dissipation, thus lengthening the period of effectiveness. To more fully evaluate the significance of high temperatures on dissipation of the four herbicides, a study was conducted exposing soil surface-applied and soil-incorporated treatments to temperatures of 40F, lOOF, 130F, and l60 F. Bioassay responses showed no significant differences be tween soil-incorporated and surface-applied chemicals as to level of dissipation . A progressive loss in herbicidal effectiveness with increasing temperature was shown for diuron, fluomturon , and prometryne, with prometryne being the most susceptible to vaporization. Diuron required a temperature of 160 F before showing significant losses, while fluometuron failed to show a significant reduction in effectiveness with increasing temperature. Conversely, chloroxuron showed a significant increase in effectiveness with an increase in temperature. Dissipation of the four herbicides over time from a glass surface after exposure to sunlight and temperatures of 40 F and 130 F was determined using the ultraviolet range of a Beckman DU spectrophotometer. Prometryne again proved to be the most unstable. In fact, prometryne losses from the 130 F treatment were greater than the progressive loss of chemical observed for the sunlight-exposed treatments. Conversely , the sunlight-exposed treatments for fluometuron, chloroxuron, and diuron showed a progressive loss of chemical in excess of that demonstrated by their respective treatments exposed to 130 F. The greater losses observed for these three herbicides suggest the importance of photodecomposition whenever they are applied to the soil surface.
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Claims 17
Claim · model-written summary
Chloroxuron at 4.0 lb/A controlled early cocklebur.
- Taxon
- soybeans
Glycine maxe1 - Treatment
- 4. 0 lb. / A chloroxurone0
- Interactor
- cocklebur
Xanthium strumariume0weed - Outcome
- control of cocklebure0
- Direction
- controle0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Early season control of cocklebur, within the limits of crop injury tolerance, was achieved using 4. 0 lb. / A chloroxuron”
e1“response of soybeans and the control of cocklebur”
Claim · model-written summary
Chloroxuron plus surfactant at 0.5 to 1.0 lb/A controlled early cocklebur.
- Taxon
- soybeansGlycine maxe2
- Treatment
- chloroxur on plus surfactant at 0. 5 to 1. 0 lb. / Ae0
- Interactor
- cockleburXanthium strumariume1weed
- Outcome
- control of cocklebure1
- Direction
- controle1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“chloroxur on plus surfactant at 0. 5 to 1. 0 lb. / A applied when weeds were 2 to 3 inches tall”
e1“Early season control of cocklebur, within the limits of crop injury tolerance, was achieved”
e2“response of soybeans and the control of cocklebur”
Claim · model-written summary
Low soil moisture required more chloroxuron for effective weed control.
- Taxon
- soybeansGlycine maxe1
- Interactor
- weedse0weed
- Outcome
- chloroxur on was required to achieve effective weed controle0
- Direction
- moree0
- Setting
- low soil moisturee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“When weeds were growing under conditions of low soil moisture, more chloroxur on was required to achieve effective weed control.”
e1“response of soybeans and the control of cocklebur”
Claim · model-written summary
Chloroxuron did not reduce soybean yield in weed-free plants.
- Taxon
- soybeansGlycine maxe0
- Treatment
- Chloroxur one0
- Outcome
- soybean yieldse0
- Direction
- did not reducee0
- Qualifier
- free of weedse0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Chloroxur on and chloroxuron plus surfactant did not reduce soybean yields when applied to soybeans growing free of weeds.”
Claim · model-written summary
Chloroxuron plus surfactant did not reduce soybean yield in weed-free plants.
- Taxon
- soybeansGlycine maxe0
- Treatment
- chloroxuron plus surfactante0
- Outcome
- soybean yieldse0
- Direction
- did not reducee0
- Qualifier
- free of weedse0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Chloroxur on and chloroxuron plus surfactant did not reduce soybean yields when applied to soybeans growing free of weeds.”
Claim · model-written summary
Mid-bloom application of 0.2 lb/A 2,4-DB controlled cocklebur.
- Taxon
- soybeanGlycine maxe0
- Organ / stage
- mid-bloom stagee0
- Treatment
- 0. 2 lb . I A r ate of 2 , 4-DBe0
- Interactor
- cockleburXanthium strumariume0weed
- Outcome
- controlled cocklebure0
- Direction
- controllede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“A 0. 2 lb . I A r ate of 2 , 4-DB applie d at mid-bloom stage of soybean development effectively controlled cocklebur”
Claim · model-written summary
Higher 2,4-DB rates tended to lower yields of weed-free soybeans.
- Taxon
- soybeansGlycine maxe0
- Treatment
- higher rates of 2 , 4-DBe0
- Outcome
- yieldse0
- Direction
- lowere0
- Qualifier
- not always significante0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Where the higher rates of 2 , 4-DB were applied on soybeans free of weeds , there was a trend toward lower yields, but the reduction in yield was not always significant.”
Claim · model-written summary
The authors recommend 2,4-DB mainly as a salvage treatment after early control fails.
- Taxon
- soybeansGlycine maxe1
- Interactor
- cockleburXanthium strumariume0weed
- Outcome
- salvage treatment to control cocklebure0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“2, 4-DB useful primarily as a salvage treatment to control cocklebur if early season control methods are ineffective”
e1“soybeans free of weeds”
Claim · model-written summary
Shallow soil incorporation reduced herbicide dissipation.
- Taxon
- soybeansGlycine maxe1
- Outcome
- herbicide dissipatione0
- Direction
- reducinge0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Shallow incorporation generally proved effective in reducing herbicide dissipation, thus lengthening the period of effectiveness.”
e1“response of soybeans and the control of cocklebur”
Claim · model-written summary
Increasing temperature progressively reduced diuron, fluometuron, and prometryne effectiveness.
- Taxon
- soybeansGlycine maxe1
- Outcome
- herbicidal effectivenesse0
- Direction
- losse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“A progressive loss in herbicidal effectiveness with increasing temperature was shown for diuron, fluomturon , and prometryne”
e1“response of soybeans and the control of cocklebur”
Claim · model-written summary
Prometryne was most susceptible to vaporization.
- Taxon
- soybeansGlycine maxe1
- Outcome
- susceptible to vaporizatione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“prometryne being the most susceptible to vaporization”
e1“response of soybeans and the control of cocklebur”
Claim · model-written summary
Diuron showed significant loss only at 160 F.
- Taxon
- soybeansGlycine maxe1
- Outcome
- significant lossese0
- Value
- 160 Fe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Diuron required a temperature of 160 F before showing significant losses”
e1“response of soybeans and the control of cocklebur”
Claim · model-written summary
Fluometuron showed no significant reduction with increasing temperature.
- Taxon
- soybeansGlycine maxe1
- Outcome
- effectivenesse0
- Direction
- failed to show a significant reductione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“fluometuron failed to show a significant reduction in effectiveness with increasing temperature”
e1“response of soybeans and the control of cocklebur”
Claim · model-written summary
Chloroxuron effectiveness significantly increased with temperature.
- Taxon
- soybeansGlycine maxe1
- Outcome
- effectivenesse0
- Direction
- increasee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“chloroxuron showed a significant increase in effectiveness with an increase in temperature”
e1“response of soybeans and the control of cocklebur”
Claim · model-written summary
Prometryne was the most unstable herbicide on glass after sunlight and heat exposure.
- Taxon
- soybeansGlycine maxe1
- Outcome
- most unstablee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Prometryne again proved to be the most unstable.”
e1“response of soybeans and the control of cocklebur”
Claim · model-written summary
Prometryne losses at 130 F exceeded progressive losses under sunlight.
- Taxon
- soybeansGlycine maxe1
- Outcome
- prometryne lossese0
- Direction
- greatere0
- Comparator
- sunlight-exposed treatmentse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“prometryne losses from the 130 F treatment were greater than the progressive loss of chemical observed for the sunlight-exposed treatments”
e1“response of soybeans and the control of cocklebur”
Claim · model-written summary
Sunlight caused greater fluometuron, chloroxuron, and diuron loss than 130 F exposure.
- Taxon
- soybeansGlycine maxe1
- Outcome
- loss of chemicale0
- Direction
- in excess ofe0
- Comparator
- treatments exposed to 130 Fe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“sunlight-exposed treatments for fluometuron, chloroxuron, and diuron showed a progressive loss of chemical in excess of that demonstrated by their respective treatments exposed to 130 F”
e1“response of soybeans and the control of cocklebur”
The same questions in other papers
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- negative
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- no effect
surfactant · Xanthium strumarium · Glycine max (soybean)Positive and negative results
1 in the opposite direction
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surfactant · yield · Glycine max (soybean)Positive and negative results
2 papers in the same direction as this paper · 4 in the opposite direction
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See all 7 papers →Claims are grouped by organism, treatment and what was measured or targeted. A paper counts as positive when any of its claims in the group is positive.