Abstract
The experiments described in this paper were designed. (1) to investigate the mechanism whereby α-naphthalene acetic acid (NAA), applied as a spray to apple trees between full bloom and two to four weeks after petal-fall, reduces the crop ; and (2) to assess the possible value of this substance as a blossom- and fruit-thinning agent.Spraying open flowers with NAA before pollination was found to induce incompatibility between the pollen tubes and the stylar tissue, and it is considered that this may account for the reduction in set which results from spraying trees at full bloom with NAA. Applied after petal- fall, the spray caused the abortion of a large proportion of the developing seeds and this, in turn, led to an abnormally large drop of young fruitlets. The seeds appeared to be susceptible to damage by NAA only as long as the endosperm was in the free nuclear stage, a condition which, in most varieties of apple, persists until about the third week after petal-fall. As a thinning agent, NAA has the disadvantage that it tends to retard fruit growth. This effect is particularly marked when the spray is applied later than two weeks after petal-fall, and frequently offsets any increase in fruit size which might have resulted from thinning. Earlier application of the spray may, in certain varieties, cause a permanent stunting of the foliage. In the strongly biennial Miller’s Seedling, none of the thinning treatments, using NAA on individual branches, resulted in the differentiation of fruit buds in the " on ” year.
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Claims 8
Claim · model-written summary
NAA spraying of trees at full bloom reduced fruit set in apple.
- Taxon
- Apples
Malus domesticat0 - Treatment
- spraying trees at full bloom with NAAe1
- Outcome
- sete1
- Direction
- reductione1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Fruit Set and Fruit Development in Apples”
e1“the reduction in set which results from spraying trees at full bloom with NAA”
Claim · model-written summary
Spraying open flowers with NAA before pollination induced incompatibility between pollen tubes and stylar tissue.
- Taxon
- ApplesMalus domesticat0
- Treatment
- Spraying open flowers with NAA before pollinatione1
- Outcome
- incompatibility between the pollen tubes and the stylar tissuee1
- Direction
- inducee1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Fruit Set and Fruit Development in Apples”
e1“Spraying open flowers with NAA before pollination was found to induce incompatibility between the pollen tubes and the stylar tissue”
Claim · model-written summary
Spraying after petal fall caused abortion of a large proportion of developing seeds.
- Taxon
- ApplesMalus domesticat0
- Treatment
- Applied after petal- fall, the spraye2
- Outcome
- abortion of a large proportion of the developing seedse2
- Direction
- causede2
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Fruit Set and Fruit Development in Apples”
e2“Applied after petal- fall, the spray caused the abortion of a large proportion of the developing seeds and this, in turn, led to an abnormally large drop of young fruitlets”
Claim · model-written summary
Spraying after petal fall led to an abnormally large drop of young fruitlets.
- Taxon
- ApplesMalus domesticat0
- Treatment
- Applied after petal- fall, the spraye2
- Outcome
- drop of young fruitletse2
- Direction
- abnormally largee2
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Fruit Set and Fruit Development in Apples”
e2“Applied after petal- fall, the spray caused the abortion of a large proportion of the developing seeds and this, in turn, led to an abnormally large drop of young fruitlets”
Claim · model-written summary
Seeds were susceptible to NAA damage only while the endosperm was in the free nuclear stage.
- Taxon
- ApplesMalus domesticat0
- Organ / stage
- endosperme3
- Outcome
- susceptible to damage by NAAe3
- Qualifier
- only as long as the endosperm was in the free nuclear stagee3
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Fruit Set and Fruit Development in Apples”
e3“The seeds appeared to be susceptible to damage by NAA only as long as the endosperm was in the free nuclear stage”
Claim · model-written summary
NAA retarded apple fruit growth, most markedly when applied later than two weeks after petal fall.
- Taxon
- ApplesMalus domesticat0
- Treatment
- NAAe4
- Outcome
- fruit growthe4
- Direction
- retarde4
- Qualifier
- particularly marked when the spray is applied later than two weeks after petal-falle5
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Fruit Set and Fruit Development in Apples”
e4“As a thinning agent, NAA has the disadvantage that it tends to retard fruit growth”
e5“This effect is particularly marked when the spray is applied later than two weeks after petal-fall”
Claim · model-written summary
Early NAA application may permanently stunt apple foliage in certain varieties.
- Taxon
- ApplesMalus domesticat0
- Treatment
- Earlier application of the spraye6
- Outcome
- foliagee6
- Direction
- permanent stuntinge6
- Qualifier
- in certain varietiese6
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Fruit Set and Fruit Development in Apples”
e6“Earlier application of the spray may, in certain varieties, cause a permanent stunting of the foliage”
Claim · model-written summary
No NAA thinning treatment on individual branches of Miller’s Seedling induced fruit bud differentiation in the on year.
- Taxon
- Miller’s Seedlinge1
- Treatment
- thinning treatments, using NAA on individual branchese2
- Outcome
- differentiation of fruit budse2
Not reportedComparatorDirection
Verbatim
e1“In the strongly biennial Miller’s Seedling”
e2“none of the thinning treatments, using NAA on individual branches, resulted in the differentiation of fruit buds”
The same questions in other papers
1-naphthaleneacetic acid · growth · Malus domestica (apple)Results differ
11 papers in the same direction as this paper · 31 in the opposite direction
- positive
- positive
- positive
39 papers more in this group
See all 43 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.