scholarly journals Benzyladenine and Other Chemicals for Thinning `Empire' Apple Trees

1993 ◽  
Vol 118 (5) ◽  
pp. 593-598 ◽  
Author(s):  
D.C. Elfving ◽  
R.A. Cline
Keyword(s):  
Fruit Set ◽  
Fruit Weight ◽  
Mineral Nutrient ◽  
Nutrient Concentrations ◽  
Naphthaleneacetic Acid ◽  
Full Bloom ◽  
Apple Trees ◽  
Return Bloom ◽  
Set Up ◽  
Better Than

Postbloom applications of benzyladenine (BA) thinned young fruitlets of mature `Empire' apple trees (Malus domestica Borkh.) as well as or better than NAA or carbaryl (CB). BA increased fruit weight more effectively than either NAA or CB. Promalin (PR) was less effective than BA for both thinning and fruit-weight increase. In 1990, both BA and PR reduced fruit set up to 29 days after full bloom, but PR showed less thinning activity. BA and NAA produced independent and additive thinning responses when tank-mixed. Effects of all thinners on foliar mineral-nutrient concentrations were associated with changes in fruit load. BA increased return bloom as much or more than NAA or CB. PR did not affect return bloom. Chemical names used: N -(phenylmethyl)-1 H -purine-6-amine [benzyladenine (BA)]; BA plus gibberellins A, and A, [Promalin (PR)]; 1-naphthaleneacetic acid (NAA); 1-naphthalenyl methylcarbamate [carbaryl (CB)].

scholarly journals EARLY SPRING APPLICATION OF AMINOETHOXYVINILGLYCINE (AVG) INCREASES FRUIT SET AND YIELD OF ‘ROCHA’ PEARS

2017 ◽  
Vol 39 (4) ◽  
Author(s):  
MATEUS DA SILVEIRA PASA ◽  
BRUNO CARRA ◽  
CARINA PEREIRA DA SILVA ◽  
MARLISE NARA CIOTTA ◽  
ALBERTO FONTANELLA BRIGHENTI ◽  
...  
Keyword(s):  
Fruit Quality ◽  
Fruit Set ◽  
Block Design ◽  
Quality Attributes ◽  
Fruit Weight ◽  
Early Spring ◽  
Full Bloom ◽  
Growing Seasons ◽  
Randomized Block Design ◽  
Return Bloom

ABSTRACT The low fruit set is one of the main factors leading to poor yield of pear orchards in Brazil. Ethylene is associated with abscission of flowers and fruitlets. Then, the application of ethylene synthesis inhibitors, such as AVG, is a potential tool to increase fruit set of pears. The objective of this study was to evaluate the effect of AVG, sprayed at different rates and timings, on fruit set, yield and fruit quality of ‘Rocha’ pear. The study was performed in a commercial orchard located in the municipality of São Joaquim, SC, during the growing seasons of 2014/2015 and 2015/2016. Plant material consisted of ‘Rocha’ pear trees grafted on quince rootstock ‘BA29’. AVG was tested at different rates (60 mg L-1 and 80 mg L-1) and timings [full bloom, one week after full bloom (WAFB), and two WAFB), either alone or in combination. The experiment was arranged in a randomized block design, with at least five single-tree replications. The fruit set, number of fruit per tree, yield, estimated yield, fruit weight, return bloom, and fruit quality attributes were assessed. Fruit set and yield were consistently increased by single applications of AVG at 60 and 80 mg L-1 at both one and two weeks after full bloom, without negatively affecting fruit quality attributes and return bloom.

scholarly journals EFFECT OF THIDIAZURON CONCENTRATION AND APPLICATION PERIOD ON ‘ROYAL GALA’ APPLE FRUITING AND PRODUCTION

2017 ◽  
Vol 39 (4) ◽  
Author(s):  
EVERLAN FAGUNDES ◽  
JOSÉ LUIZ PETRI ◽  
LUIZ CARLOS ARGENTA ◽  
FERNANDO JOSÉ HAWERROTH ◽  
MARCELO COUTO
Keyword(s):  
Fruit Set ◽  
Polynomial Regression ◽  
Fruit Weight ◽  
Climatic Conditions ◽  
Experimental Unit ◽  
Southern Brazil ◽  
Apple Trees ◽  
Test Analysis ◽  
Mild Winter ◽  
Return Bloom

ABSTRACT ‘Gala’ apple trees have low fruit set in restrictive pollination situations, being an obstacle to the achievement of high production rates in orchards in southern Brazil, which can be minimized by the use of growth regulators. The aim of this study was to evaluate the effect of thidiazuron concentrations in ‘Royal Gala’ apple fruiting and production, grown in mild winter conditions. The experiment was conducted during the 2011/2012, 2012/2013 and 2013/2014 crop years in Fraiburgo, SC, on ‘Royal Gala’ apple trees in Marubakaido rootstock M9 with filter. In all evaluation cycles, the experimental design was a randomized block with factorial arrangement (6x2) with six TDZ concentrations and two application forms, with six replicates, and the experimental unit consisting of one plant. The TDZ concentrations of each treatment were applied split into two seasons. The first application was performed on pink bud stage (E2) and the second application was in full bloom stage (F2). The variables evaluated were: fruit set (%), return bloom (%), number and weight of fruits per plant, mean fruit weight (g) and average number of seeds per fruit. Data were submitted to analysis of variance, in which for significant variables by the F test, analysis of contrast and polynomial regression were performed in order to evaluate the response of variables with increasing TDZ concentration. TDZ is effective even at low concentrations, increasing the production and fruit set of ‘Gala’ apples in the climatic conditions of southern Brazil.

scholarly journals 184 Timing of Benzyladenine Application as a Chemical Thinner of `Empire' Apple

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 455d-455 ◽  
Author(s):  
V. E. Emongor ◽  
D. P. Murr
Keyword(s):  
Fruit Quality ◽  
Ethylene Production ◽  
Fruit Set ◽  
Fruit Size ◽  
Fruit Weight ◽  
Seed Number ◽  
Full Bloom ◽  
Apple Trees ◽  
Effective Time ◽  
Fruit Diameter

Benzyladenine (100 or 200 mg.litre-1) was applied to mature Empire/M.26 apple trees as dilute sprays 2, 4, 9, 11, 13, 15, 17, 20, 25, 27, 29 or 31 days after full bloom (DAFB). The most effective time of thinning was 25-29 DAFB (king fruit diameter 8.94-13.91 mm), and the thinning response to BA concentration was linear. Benzyladenine (BA) did not reduce fruit set when king fruit diameter was less than 5.35 mm, but BA significantly increased fruit weight, diameter (D), length (L) and L:D ratio compared to unsprayed controls and later BA treatments. BA - treated fruitlets had higher ethylene production, 24 hours and 7 days after spraying compared to untreated controls. We suggest that the response of apple fruitlets to BA applied as a thinner is mediated by ethylene. High fruit quality was obtained when BA was applied at 17-31 DAFB. Timing of BA sprays had no effect on seed number, though BA significantly increased seed number, fruit size, weight and L:D ratio. These results suggest that BA has the potential to substitute for the use of carbaryl as a thinner of apples in Ontario orchards.

scholarly journals Ethylene Evolution from Detached Apple Spurs in Response to Chemical Thinners

HortScience ◽  
2002 ◽  
Vol 37 (4) ◽  
pp. 662-665 ◽  
Author(s):  
Steven J. McArtney
Keyword(s):  
Phosphonic Acid ◽  
Fruit Set ◽  
Average Diameter ◽  
Naphthaleneacetic Acid ◽  
Similar Amount ◽  
Full Bloom ◽  
Ethylene Evolution ◽  
Apple Trees ◽  
Fruit Abscission ◽  
Initial Drop

Ethylene evolution from detached fruiting apple spurs was measured after application of various bloom and post-bloom thinning agents. Ethylene evolution from fresh detached spurs of `Splendor' apple trees increased one day after application of a bloom thinning spray of ethephon or NAA, and remained higher than rates of ethylene evolution by detached spurs from unsprayed control trees for 6 (NAA) or 10 (ethephon) days. Both ethylene evolution and fruit abscission during the initial drop period were higher on trees treated with ethephon compared to NAA, however final fruit set was similar for these two treatments. Ethylene evolution was significantly higher following NAA application onto `Fuji' trees compared with NAAm, but final fruit set was reduced by a similar amount (≈20%) for both of these materials. Application of BA to `Pacific Rose™' apple trees when the average diameter of spur fruit was either 4 mm (6 days after full bloom) or 7 mm (12 days after full bloom) resulted in a significant increase in the rate of ethylene evolution and also reduced final fruit set. When application of BA was delayed until the average diameter of spur fruit was 14 mm (24 days after full bloom) neither the rate of ethylene evolution or final fruit set was affected. Although an increase in the rate of ethylene evolution was a prerequisite for thinning in the present experiments, the magnitude of this increase was not related to the final thinning efficacy. Chemical names used: benzyladenine (BA); 2-chloroethyl phosphonic acid (ethephon); naphthaleneacetic acid (NAA); naphthalene acetamide (NAAm).

scholarly journals Thidiazuron Effects on Fruit Set, Fruit Quality, and Return Bloom of Apples

HortScience ◽  
1995 ◽  
Vol 30 (6) ◽  
pp. 1238-1240 ◽  
Author(s):  
Duane W. Greene
Keyword(s):  
Fruit Set ◽  
Fruit Weight ◽  
Soluble Solids ◽  
Refrigerated Storage ◽  
Full Bloom ◽  
Crop Load ◽  
Flesh Firmness ◽  
Solids Concentration ◽  
Return Bloom ◽  
Soluble Solids Concentration

Thidiazuron (THI) applied at full bloom (FB) at 10 or 50 mg·liter–1 thinned `McIntosh' apples (Malus domestica Borkh.) and reduced return bloom. The same concentrations applied at 22 days after FB (DAFB) thinned excessively and inhibited return bloom even more. THI at 1, 5, or 15 mg·liter–1 did not thin `Empire' at FB, but when applied 18 DAFB, these concentrations achieved thinning, with 5 mg·liter–1 reducing crop load to near ideal commercial levels. Return bloom of `Empire' was not influenced by THI at these concentrations. THI increased fruit weight, flesh firmness, soluble solids concentration, and fruit asymmetry on `McIntosh' and `Empire' and reduced red pigmentation and seed count on `McIntosh', especially when applied 22 DAFB. A FB application of CPPU and THI, each at 5 or 10 mg·liter–1, on `Delicious' increased the fruit length: diameter (L: D) ratio and flesh firmness (at harvest and following 26 weeks of refrigerated storage and reduced return bloom). CPPU at either 5 or 10 mg·liter–1 increased the fruit L: D ratio more than 25 mg Promalin/liter. Chemical names used: N-phenyl-N′-1,2,3-thiadiazol-5-ylurea (thidiazuron); N-(2-chloro-4-pyridyl)-N′-phenylurea (CPPU); N-(phenylmethyl)-1H-purine-6-amine plus gibberellins A4+7 (Promalin).

scholarly journals Almond Fruit Drop Patterns under Mediterranean Conditions

Agriculture ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 544
Author(s):  
Jaume Lordan ◽  
Lourdes Zazurca ◽  
Mercè Rovira ◽  
Laura Torguet ◽  
Ignasi Batlle ◽  
...  
Keyword(s):  
Fruit Set ◽  
Growing Season ◽  
Fruit Weight ◽  
Key Factors ◽  
Full Bloom ◽  
Tree Management ◽  
Fruit Drop ◽  
Mediterranean Conditions ◽  
New Cultivars ◽  
Scion Cultivar

Almond is an important tree nut crop worldwide, and planted areas have been increasing year after year. While self-fertility is one of the key factors when it comes to improved almond productivity of new cultivars, yield is also affected by the number of flowers produced, pollination, fruit set, fruit drop, and fruit weight. Almond fruit drop patterns of 20 Mediterranean almond cultivars were studied over three years. In addition, fruit drop patterns of two scion cultivars ‘Marinada’ and ‘Vairo’ budded onto eight to 10 different rootstocks managed with three different pruning strategies were studied for two years. Cumulative flower and fruit drop ranged from 50% to 90% among cultivars and treatments, and there were up to four fruit drop events during the growing season, the main one occurring from 20–60 days from full bloom (DFFB). Subsequent drops were at 100 DFFB, 120–140 DFFB, and the last one at 160–180 DFFB. The later drops were less apparent. In general, about half of the cumulative drop was comprised of buds and flowers, and the remaining percentage was fruit that dropped 20 or more days after full bloom. Furthermore, different fruit drop patterns were observed depending on the cultivar. For late- and extra-late flowering cultivars, cumulative fruit drop began to decrease earlier, with most of the drops occurred already at full bloom, whereas the opposite was observed for the early flowering cultivars. Rootstocks also had an important effect on the fruit drop pattern, with different effects depending on the scion cultivar. Tree management, such as type of pruning, also had an important effect on the rate of fruit drop and cumulative drop. Therefore, each combination of cultivar × rootstock × pruning type will require different strategies in order to reduce the fruit drop and optimize crop loads.

scholarly journals Combinations of Ethephon and Accel for Thinning `Delicious' Apple Trees

2004 ◽  
Vol 129 (2) ◽  
pp. 175-181 ◽  
Author(s):  
Richard P. Marini
Keyword(s):  
Phosphonic Acid ◽  
Fruit Set ◽  
Fruit Weight ◽  
Analysis Of Covariance ◽  
Apple Trees ◽  
Fruit Diameter

For 4 years, `Redchief Delicious' apple [Malus ×sylvestris (L.) Mill. var. domestica (Borkh.) Mansf.] trees were treated with ethephon and/or Accel (6-BA + Gibberellins 4+7) when average fruit diameter was 5.0 to 11.4 mm. Effective thinning was obtained with ethephon at concentrations >500 mg·L-1 and with Accel at concentrations of 100 to 125 mg·L-1. In only 1 year out of 4 did combinations of Accel plus ethephon reduce fruit set more than either material applied alone. Repeat applications of either material alone or in combination reduced fruit set no more than single applications. Fruit weight was negatively related to the number of fruit per tree. After adjusting fruit weight for number of fruit per tree at harvest with analysis of covariance, ethephon did not improve fruit weight at harvest, but Accel improved fruit weight in two of three experiments. The effect of combinations of Accel and ethephon on fruit weight was inconsistent. Chemical names used: 2-chloroethyl phosphonic acid (ethephon); polyothyethylleneploypropanol dihydroxy-propane 2, butoxyethanol (Regulaid); N-(phenylmethyl)-1H-purine-6-amine plus giberrellins A4 + A7 (Accel).

scholarly journals Optimal Nutrient Concentration Ranges of ‘Hass’ Avocado Cauliflower Stage Inflorescences—Potential Diagnostic Tool to Optimize Tree Nutrient Status and Increase Yield

HortScience ◽  
2017 ◽  
Vol 52 (12) ◽  
pp. 1707-1715 ◽  
Author(s):  
Salvatore Campisi-Pinto ◽  
Yusheng Zheng ◽  
Philippe E. Rolshausen ◽  
David E. Crowley ◽  
Ben Faber ◽  
...  
Keyword(s):  
Nutrient Concentration ◽  
Fruit Set ◽  
Fruit Size ◽  
Nutrient Status ◽  
Persea Americana ◽  
Nutrient Concentrations ◽  
Full Bloom ◽  
Nutrient Analysis ◽  
Tree Phenology ◽  
Hass Avocado

Optimizing ‘Hass’ avocado (Persea americana Mill.) tree nutrient status is essential for maximizing productivity. Leaf nutrient analysis is used to guide avocado fertilization to maintain tree nutrition. The goal of this research was to identify a ‘Hass’ avocado tissue with nutrient concentrations predictive of yields greater than 40 kg of fruit per tree. This threshold was specified to assist the California avocado industry to increase yields to ≈11,200 kg·ha−1. Nutrient concentrations of cauliflower stage inflorescences (CSI) collected in March proved better predictors of yield than inflorescences collected at full bloom (FBI) in April, fruit pedicels (FP) collected at five different stages of avocado tree phenology from the end of fruit set in June through April the following spring when mature fruit enter a second period of exponential growth, or 6-month-old spring flush leaves (LF) from nonbearing vegetative shoots collected in September (California avocado industry standard). For CSI tissue, concentrations of seven nutrients, nitrogen (N), phosphorus (P), potassium (K), magnesium (Mg), sulfur (S), zinc (Zn), and copper (Cu) were predictive of trees producing greater than 40 kg of fruit annually. Conditional quantile sampling and frequency analysis were used to identify optimum nutrient concentration ranges (ONCR) for each nutrient. Optimum ratios between nutrient concentrations and yields greater than 40 kg per tree were also derived. The high nutrient concentrations characterizing CSI tissue suggest current fertilization practices (timing or amounts) might be causing nutrient imbalances at this stage of avocado tree phenology that are limiting productivity, a possibility that warrants further investigation. Because CSI samples can be collected 4–6 weeks before full bloom, nutritional problems can be addressed before they affect flower retention and fruit set to increase current crop yield, fruit size, and quality. Thus, CSI nutrient analysis warrants further research as a potential supplemental or alternative tool for diagnosing ‘Hass’ avocado tree nutrient status and increasing yield.

Control of pudding spot in Crofton apple

1992 ◽  
Vol 32 (4) ◽  
pp. 503
Author(s):  
KM Jones ◽  
SA Bound ◽  
MJ Oakford ◽  
TB Koen
Keyword(s):  
Acetic Acid ◽  
Fruit Size ◽  
Fruit Weight ◽  
The Other ◽  
Naphthalene Acetic Acid ◽  
Full Bloom ◽  
Apple Trees ◽  
Low Incidence ◽  
Thinning Effect

Regularly cropped Crofton apple trees in southern Tasmania were thinned using sprays of naphthalene acetic acid (NAA) at 10 mg/L or ethephon at 200 mg/L at balloon blossom (BB), full bloom (FB), 10 days after full bloom (DAFB) or 20 DAFB. These treatments were compared with hand thinning and an unthinned control. Ethephon had a uniformly mild thinning effect (about 30% compared to control), except at 10 DAFB, where no thinning occurred. NAA was inconsistent, thinning well at BB (50%), overthinning at both FB (85%) and 10 DAFB (88%), and underthinning at 20 DAFB (similar to the control). Ethephon applied at BB and FB increased both mean fruit weight (12 and 22%) and fruit size (28 and 79%), but later applications did not. NAA applications generally resulted in increased mean fruit weight and size, except for the 20 DAFB treatment, which was similar to the control. All ethephon treatments had a low incidence (43%) of pudding spot similar to the controls and hand-thinned treatments. Most NAA treatments showed significantly higher levels of pudding spot than the other treatments. It is concluded that ethephon is a more predictable thinner for Crofton than NAA, and its use to control pudding spot is recommended.

scholarly journals EFFECTS OF HYDROGEN CYANAMIDE ON APPLE AND PLUM FRUIT THINNING

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 690a-690
Author(s):  
Esmaeil Fallahi ◽  
Brenda R. Simons ◽  
John K. Fellman ◽  
W. Michael Colt
Keyword(s):  
Malus Domestica ◽  
Fruit Set ◽  
Fruit Size ◽  
Apple Fruit ◽  
Fruit Weight ◽  
Full Bloom ◽  
Hydrogen Cyanamide ◽  
Fruit Thinning ◽  
Prunus Salicina

Influence of various concentrations of hydrogen cyanamide (HC) on fruit thinning of `Rome Beauty' apple (Malus domestica Borkh.), `Friar,' and `Simka' plums (Prunus salicina Lindley) were studied. A full bloom application of HC at all tested concentrations decreased `Rome Beauty' apple fruit set and yield, and increased fruit weight. Hydrogen cyanamide at 0.25% (V/V) resulted in adequate apple thinning, indicated by the production of an ideal fruit weight. Prebloom and full bloom applications of HC at greater than 0.75% reduced plum fruit set and yield in `Friar.' Full bloom application of HC at 0.25% to 0.50% showed a satisfactory fruit set, yield, and fruit size in `Friar' plum. Full bloom application decreased fruit set and yield in `Simka' plum. Hand thinning, as well as chemical thinning, is recommended for plums.

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