Abstract
From 1947 to 1950, 34 field experiments were conducted to study the effects of applications of 2,4-D and related substances on fruit-drop, yield, size, and quality of grapefruit in California. It was found that water sprays of 8 ppm 2,4-D reduced mature fruit-drop an average of 44 per cent, as compared with nonsprayed trees, and that this response to 2,4-D occurred under a wide range of climatic and environmental conditions. This spray was more effective in reducing fruit-drop when applied in May than when applied in July, and annual applications of 2,4-D for three years have shown no accumulative detrimental effects. The differences in fruit-drop resulting from the use of various forms of 2,4-D were not great. Thus far, 2,4-D has not proved incompatible with any agricultural spray chemicals, and has been effective in reducing mature fruit-drop when applied in conjunction with other spray treatments. The 2,4-D sprays had no undesirable effects on the quality of fruit which was mature, or nearly mature, at the time of spraying. Trees sprayed with 2,400 ppm 2,4-D as a kerosene “aeromist” at less than 10 gallons per acre showed a reduction in mature fruit-drop, as compared with nonsprayed trees, but this method cannot yet be recommended for commercial use. A water spray of 8 ppm 2,4,5-T was as effective as an 8 ppm 2,4-D spray in reducing mature fruit-drop. A spray of 25 ppm naphthalene-acetic acid was not effective, and a spray of 25 ppm naphthoxyacetic acid was only slightly effective. Application of 8 ppm 2,4-D to trees with young, expanding leaves induced a curling and deformation of the leaves. Subsequent leaf growth was normal. Application of the spray between leaf growth flushes minimized the distortion. No influence on yield or fruit quality was noted as a result of the leaf curl. There was an increase in fruit size of commercial value if the correct concentration of 2,4-D was sprayed on trees bearing fruit less than 16 weeks old. However, the fruit quality was lowered when trees bearing young fruit (less than 16 weeks) were sprayed with 2,4-D at too high a concentration in relation to the stage of fruit growth. A lowering in quality as a result of an 8 ppm 2,4-D spray was observed in only one experiment, where the application was made on trees in full bloom.
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Claims 17
Claim · model-written summary
An 8 ppm 2,4-D water spray reduced mature fruit drop by 44 per cent versus unsprayed trees.
- Taxon
- grapefruit
_Pompelino_Grapefruit_002.jpg?width=60)
Citrus ×paradisit0 - Treatment
- water sprays of 8 ppm 2,4-De0
- Outcome
- mature fruit-drope0
- Direction
- reducede0
- Value
- 44 per cente0
- Comparator
- nonsprayed treese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
_Pompelino_Grapefruit_002.jpg?width=500)
Verbatim
e0“water sprays of 8 ppm 2,4-D reduced mature fruit-drop an average of 44 per cent, as compared with nonsprayed trees”
t0“Effects of 2,4-D and related substances on fruit-drop, yield, size, and quality of grapefruit”
Claim · model-written summary
A May application reduced fruit drop more than a July application.
- Taxon
- grapefruitCitrus ×paradisit0
- Treatment
- applied in Maye0
- Outcome
- fruit-drope0
- Direction
- more effective in reducinge0
- Comparator
- applied in Julye0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“This spray was more effective in reducing fruit-drop when applied in May than when applied in July”
t0“Effects of 2,4-D and related substances on fruit-drop, yield, size, and quality of grapefruit”
Claim · model-written summary
Three years of annual 2,4-D application showed no cumulative detrimental effects.
- Taxon
- grapefruitCitrus ×paradisit0
- Treatment
- annual applications of 2,4-D for three yearse0
- Outcome
- no accumulative detrimental effectse0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“annual applications of 2,4-D for three years have shown no accumulative detrimental effects”
t0“Effects of 2,4-D and related substances on fruit-drop, yield, size, and quality of grapefruit”
Claim · model-written summary
Different forms of 2,4-D yielded little difference in fruit drop.
- Taxon
- grapefruitCitrus ×paradisit0
- Treatment
- various forms of 2,4-De0
- Outcome
- fruit-drope0
- Direction
- not greate0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The differences in fruit-drop resulting from the use of various forms of 2,4-D were not great”
t0“Effects of 2,4-D and related substances on fruit-drop, yield, size, and quality of grapefruit”
Claim · model-written summary
2,4-D remained effective against fruit drop in combination with other spray treatments.
- Taxon
- grapefruitCitrus ×paradisit0
- Treatment
- 2,4-Dt0
- Outcome
- mature fruit-drope0
- Direction
- reducinge0
- Qualifier
- in conjunction with other spray treatmentse0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“has been effective in reducing mature fruit-drop when applied in conjunction with other spray treatments”
t0“Effects of 2,4-D and related substances on fruit-drop, yield, size, and quality of grapefruit”
Claim · model-written summary
2,4-D sprays had no undesirable effects on quality of fruit mature or nearly mature at spraying.
- Taxon
- grapefruitCitrus ×paradisit0
- Treatment
- 2,4-D sprayse0
- Outcome
- quality of fruite0
- Direction
- no undesirable effectse0
- Qualifier
- mature, or nearly maturee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The 2,4-D sprays had no undesirable effects on the quality of fruit which was mature, or nearly mature, at the time of spraying”
t0“Effects of 2,4-D and related substances on fruit-drop, yield, size, and quality of grapefruit”
Claim · model-written summary
A 2,400 ppm 2,4-D kerosene aeromist reduced mature fruit drop versus unsprayed trees.
- Taxon
- grapefruitCitrus ×paradisit0
- Treatment
- 2,400 ppm 2,4-D as a kerosene “aeromist” at less than 10 gallons per acree0
- Outcome
- mature fruit-drope0
- Direction
- reductione0
- Comparator
- nonsprayed treese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Trees sprayed with 2,400 ppm 2,4-D as a kerosene “aeromist” at less than 10 gallons per acre showed a reduction in mature fruit-drop, as compared with nonsprayed trees”
t0“Effects of 2,4-D and related substances on fruit-drop, yield, size, and quality of grapefruit”
Claim · model-written summary
An 8 ppm 2,4,5-T water spray was as effective as 8 ppm 2,4-D for fruit drop.
- Taxon
- grapefruitCitrus ×paradisit0
- Treatment
- water spray of 8 ppm 2,4,5-Te0
- Outcome
- mature fruit-drope0
- Direction
- as effectivee0
- Comparator
- 8 ppm 2,4-D spraye0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“A water spray of 8 ppm 2,4,5-T was as effective as an 8 ppm 2,4-D spray in reducing mature fruit-drop”
t0“Effects of 2,4-D and related substances on fruit-drop, yield, size, and quality of grapefruit”
Claim · model-written summary
A 25 ppm naphthalene-acetic acid spray was ineffective.
- Taxon
- grapefruitCitrus ×paradisit0
- Treatment
- spray of 25 ppm naphthalene-acetic acide0
- Outcome
- not effectivee0
- Direction
- not effectivee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“A spray of 25 ppm naphthalene-acetic acid was not effective”
t0“Effects of 2,4-D and related substances on fruit-drop, yield, size, and quality of grapefruit”
Claim · model-written summary
A 25 ppm naphthoxyacetic acid spray was only slightly effective.
- Taxon
- grapefruitCitrus ×paradisit0
- Treatment
- spray of 25 ppm naphthoxyacetic acide0
- Outcome
- only slightly effectivee0
- Direction
- only slightly effectivee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“a spray of 25 ppm naphthoxyacetic acid was only slightly effective”
t0“Effects of 2,4-D and related substances on fruit-drop, yield, size, and quality of grapefruit”
Claim · model-written summary
Applying 8 ppm 2,4-D to trees with expanding young leaves induced leaf curl and deformation.
- Taxon
- grapefruitCitrus ×paradisit0
- Organ / stage
- young, expanding leavese0
- Treatment
- 8 ppm 2,4-De0
- Outcome
- curling and deformation of the leavese0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Application of 8 ppm 2,4-D to trees with young, expanding leaves induced a curling and deformation of the leaves”
t0“Effects of 2,4-D and related substances on fruit-drop, yield, size, and quality of grapefruit”
Claim · model-written summary
Leaf growth after the spray was normal.
- Taxon
- grapefruitCitrus ×paradisit0
- Outcome
- leaf growth was normale0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Subsequent leaf growth was normal”
t0“Effects of 2,4-D and related substances on fruit-drop, yield, size, and quality of grapefruit”
Claim · model-written summary
Spraying between leaf growth flushes minimized leaf distortion.
- Taxon
- grapefruitCitrus ×paradisit0
- Treatment
- spray between leaf growth flushese0
- Outcome
- distortione0
- Direction
- minimizede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Application of the spray between leaf growth flushes minimized the distortion”
t0“Effects of 2,4-D and related substances on fruit-drop, yield, size, and quality of grapefruit”
Claim · model-written summary
Leaf curl did not influence yield or fruit quality.
- Taxon
- grapefruitCitrus ×paradisit0
- Organ / stage
- leafe0
- Outcome
- yield or fruit qualitye0
- Direction
- No influencee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“No influence on yield or fruit quality was noted as a result of the leaf curl”
t0“Effects of 2,4-D and related substances on fruit-drop, yield, size, and quality of grapefruit”
Claim · model-written summary
Appropriate 2,4-D concentration increased commercially valuable fruit size when fruit was under 16 weeks old.
- Taxon
- grapefruitCitrus ×paradisit0
- Treatment
- correct concentration of 2,4-De0
- Outcome
- fruit size of commercial valuee0
- Direction
- increasee0
- Qualifier
- fruit less than 16 weeks olde0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“There was an increase in fruit size of commercial value if the correct concentration of 2,4-D was sprayed on trees bearing fruit less than 16 weeks old”
t0“Effects of 2,4-D and related substances on fruit-drop, yield, size, and quality of grapefruit”
Claim · model-written summary
Excessive 2,4-D concentration lowered quality of young fruit.
- Taxon
- grapefruitCitrus ×paradisit0
- Treatment
- 2,4-D at too high a concentratione0
- Outcome
- fruit qualitye0
- Direction
- lowerede0
- Qualifier
- young fruit (less than 16 weeks)e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the fruit quality was lowered when trees bearing young fruit (less than 16 weeks) were sprayed with 2,4-D at too high a concentration in relation to the stage of fruit growth”
t0“Effects of 2,4-D and related substances on fruit-drop, yield, size, and quality of grapefruit”
Claim · model-written summary
An 8 ppm 2,4-D spray lowered fruit quality in one full-bloom experiment.
- Taxon
- grapefruitCitrus ×paradisit0
- Organ / stage
- full bloome0
- Treatment
- 8 ppm 2,4-D spraye0
- Outcome
- qualitye0
- Direction
- loweringe0
- Qualifier
- only one experimente0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“A lowering in quality as a result of an 8 ppm 2,4-D spray was observed in only one experiment, where the application was made on trees in full bloom”
t0“Effects of 2,4-D and related substances on fruit-drop, yield, size, and quality of grapefruit”
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See all 9 papers →application · quality: general · Citrus x paradisi (grapefruit)Results agree
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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.