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 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 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.

scholarly journals Regulating Budbreak, Flowering, and Fruit Maturity in Sweet Cherry (Prunus avium L.) cv. `Bing' by Surfactant and Nitrate Applications

HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 603e-603
Author(s):  
K.G. Weis ◽  
S.M. Southwick ◽  
J.T. Yeager ◽  
W.W. Coates ◽  
Michael E. Rupert
Keyword(s):  
Sweet Cherry ◽  
Prunus Avium ◽  
Fruit Set ◽  
Fruit Size ◽  
Calcium Nitrate ◽  
Potassium Nitrate ◽  
Fruit Weight ◽  
Full Bloom ◽  
Fruit Maturity ◽  
Flower And Fruit Development

The years 1995 and 1996 were low chill years in California with respect to stone fruit dormancy. Advancing reproductive budbreak and flowering was accomplished in `Bing' cherry (Prunus avium) by single-spray treatments of a surfactant {a polymeric alkoxylated fatty amine [N,N-bis 2-(omega-hydroxypolyoxyethylene/polyoxypropylene) ethyl alkylamine]} and potassium nitrate in combination when applied at “tightbud,” ≈ 42 days (1 Feb. 1995) before full bloom and with surfactant and potassium nitrate in combination when 10% green calyx was apparent, 33 days before full bloom. Applying 2% surfactant (v/v) + 6% potassium nitrate (w/v) was most effective in advancing bloom, speeding progression through bloom, and advancing fruit maturity when applied at tightbud stage. Surfactant (2% or 4%) applied with 25% or 35% calcium nitrate (w/v) on 2 Feb. 1996 significantly advanced full bloom compared to nontreated controls. Fruit maturity (1995) was somewhat advanced by surfactant–nitrate treatments, but fruit set and final fruit weight were equivalent among treatments. No phytotoxicity was noted in foliage or fruit. In California, marginal and insufficient winter chilling often causes irregular, extended, or delayed bloom periods, resulting in poor bloom-overlap with pollenizers. As a result, flower and fruit development may be so variable as to have small, green and ripe fruit on the same tree, making harvest more time consuming and costly. Data indicate that this surfactant, in combination with a nitrogenous compound, has potential to advance reproductive budbreak and advance maturity in sweet cherry without reducing fruit set or fruit size. Advancing the ripening time of sweet cherry even 2 to 3 days can increase the price received per 8.2-kg box by $10 to $20.

scholarly journals EFFECT OF ROOT PRUNING AND CHEMICAL THINNING ON GROWTH AND FRUITING OF `McINTOSH' APPLE TREES.

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1153b-1153
Author(s):  
James R. Schupp ◽  
Highmoor Farm
Keyword(s):  
Fruit Set ◽  
Fruit Size ◽  
Shoot Length ◽  
Root Pruning ◽  
Full Bloom ◽  
Apple Trees ◽  
Cross Sectional ◽  
Fruit Drop ◽  
Napthaleneacetic Acid ◽  
Fruit Diameter

Mature `McIntosh'/MM.111 apple (Malus domestica, Borkh.) trees were treated to evaluate the response of root pruned trees to chemical thinning and to determine if reducing the crop load increased fruit size on root pruned trees. The trees were root pruned at full bloom in 1988 and 1989, by cutting on both sides of the row 1m from the trunk and 30cm deep. Water, 600mg/liter carbaryl, 5mg/liter napthaleneacetic acid (NAA), or NAA plus carbaryl were applied when fruit diameter was approximately 10mm. Trunk cross-sectional area (TCSA) was increased by thinning treatments in 1988, but root pruning had no effect. In 1989, root pruning reduced TCSA increment by 35%. Shoot length was reduced by root pruning both years. All treatments reduced percent fruit set in 1989, however root pruned trees and trees treated with NAA had the highest fruit numbers at harvest. Preharvest fruit drop was reduced by root pruning in both 1988 and 1989. Root pruning had no influence on the response of apple trees to chemical thinning. Removing a portion of the crop with chemical thinners was partially successful in counteracting the reduction in fruit size caused by root pruning.

scholarly journals BLOOM THINNING OF FUJI, ROYAL GALA, AND BRAEBURN APPLE WITH MONOCARBAMIDE DIHYDROGENSULFATE

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 591f-591 ◽  
Author(s):  
Stephen C. Myers ◽  
Steven McArtney ◽  
Stuart Tustin ◽  
Wendy Cashmore ◽  
Richard Mangin
Keyword(s):  
Fruit Set ◽  
Fruit Weight ◽  
Soluble Solids ◽  
Linear Effect ◽  
Fruit Drop ◽  
Solids Concentration ◽  
Root Stock ◽  
Drying Conditions ◽  
Mature Apple ◽  
Soluble Solids Concentration

Foliar applications of monocarbamide dihydrogensulfate (D-88, Unocal Chemicals Division) at rates of 0, 2.5 ml/1, 3.75 ml/1 or 5.0 ml/1 were made to mature apple trees of “Fuji”, “Royal Gala” or “Braeburn” on MM106 root-stock. Treatments were applied dilute when spurs were at 95% full bloom. D-88 was applied at 5.0 ml/1 to “Fuji” at three different times during the day (0730, 1400 or 1810) with and without surfactant in an attempt to evaluate the effect of different atmospheric and drying conditions. Fruit set (number of fruit per 100 flower clusters) was determined after natural fruit drop. D-88 had no effect on fruit set of “Royal Gala” or “Braeburn”. There was a linear effect between D-88 rate and fruit set on “Fuji”, with the 5.0 ml/1 rate reducing set by 30%. D-88 affected the number of fruit at individual fruiting sites, most significantly the percentage of flower clusters setting 3 fruits decreasing with increasing rate. Timing and surfactant had no effect. Fruit finish, mean fruit weight, seed number and soluble solids concentration were measured at harvest.

scholarly journals GA3—INDUCED FRUIT SET OF RABBITEYE BLUEBERRY

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 689c-689
Author(s):  
Raguel Cano—M ◽  
Rebecca L. Darnell
Keyword(s):  
Fruit Quality ◽  
Fruit Development ◽  
Fruit Set ◽  
Total Yield ◽  
Titratable Acidity ◽  
Fruit Weight ◽  
Soluble Solids ◽  
Full Bloom ◽  
Development Period

The effects of different GA3 concentrations and application times on fruit set, fruit development period, and fruit quality in rabbiteye blueberry (Vaccinium ashei Reade) were studied. Flower clusters were sprayed with 100 or 250 ppm GA3 at 90% full bloom and again 7 days later, or with 125 ppm GA3 at 90% full bloom and again 7, 21, and 42 days later, under greenhouse conditions. Fruit set was monitored every 10 days and fruit weight, fruit development period, soluble solids, and titratable acidity were measured at harvest. Fruit set in GA3 treatments averaged 69 to 76% compared to an average of 43% for the pollinated control. Weight of GA3 treated berries averaged 1.2, g while that of pollinated berries averaged 2.0 g. However, calculated total yield was greater for the GA3 treatments compared to the pollinated control, averaging 244 and 206 g/treatment, respectively. GA3 increased the fruit development period by 2 to 11 days, depending on the treatment. Soluble solids and titratable acidity were not affected by any treatment.

Re-evaluation of a Desiccating Surfactant for Thinning Peach Blossoms

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 496c-496
Author(s):  
R.C. Ebel ◽  
D.G. Himelrick ◽  
A. Caylor ◽  
J. Pitts
Keyword(s):  
Polyethylene Glycol ◽  
Prunus Persica ◽  
Fruit Set ◽  
Fruit Weight ◽  
Negative Effects ◽  
Full Bloom ◽  
Peach Trees ◽  
Linear Correlations ◽  
Dodecyl Ether

The surfactant “Surfactant WK” (dodecyl ether of polyethylene glycol) was applied to peach trees [Prunus persica (L.) Batsch] at full bloom over 3 years. Blossoms died rapidly, so that within 2 days dead blossoms could be distinguished easily from live blossoms or set fruit. There were strong (R2 > 0.87), linear correlations between concentration of “Surfactant WK” applied and percent blossoms removed and fruit set, which were similar over the 3 years. Trees were hand-thinned according to commercial practices after treatment. There was similar cropload, fruit weight and yield across treatments at harvest indicating no negative effects by the chemical on productivity. There was only slight limb damage at the highest concentrations of “Surfactant WK”, which over thinned blossoms. We recommend that based on the effectiveness, consistency, and lack of significant phytotoxicity, “Surfactant WK” be re-evaluated as a thinning chemical for peach trees.

scholarly journals Tergitol as a possible thinning agent for peach cv. Redhaven

2014 ◽  
Vol 41 (No. 2) ◽  
pp. 49-54 ◽  
Author(s):  
B. Ambrožič Turk ◽  
N. Fajt ◽  
M. Stopar
Keyword(s):  
Fruit Set ◽  
Fruit Weight ◽  
Size Class ◽  
Full Bloom ◽  
Ammonium Thiosulfate ◽  
South West ◽  
Peach Trees ◽  
Thinning Effect ◽  
Fruit Diameter

The effect of different blossom thinners ammonium thiosulfate (ATS) (1%, 2%), Armothin (1.5%), Tergitol-TMN-6 (0.5%, 1%), applied on peach cv. Redhaven at 50–60% full bloom was evaluated in thinning experiments in south-west Slovenia. The photosynthesis inhibitor metamitron (0.05%) applied at 8 mm fruit diameter was evaluated as fruitlet thinner as well. Application of 2% ATS resulted in excessive thinning. The thinning effect of 1% ATS was also too strong in two out of three thinning experiments. The use of 0.05% metamitron did not cause any thinning effect on peach trees and gave similar results as the non-treated control. The effective fruit set reduction and increase of average fruit weight was achieved with 0.5% and 1% Tergitol application. In three-year experiment both Tergitol applications reduced fruit set toward hand thinned level, but the share of fruit from bigger size class was only once enhanced to the level of hand thinned trees. No sign of phytotoxicity was noticed on fruits in all thinner application treatments.  

scholarly journals FACTORS INFLUENCING PREHARVEST FRUIT SPLITTING IN ELLENDALE (C. reticulata).

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1135f-1135 ◽  
Author(s):  
Etienne Rabe ◽  
Piet van Rensburg ◽  
Hennie van der Walt ◽  
John Bower
Keyword(s):  
Gibberellic Acid ◽  
Fruit Set ◽  
Significant Shift ◽  
Full Bloom ◽  
Fruit Drop ◽  
Factors Influencing ◽  
Seed Content ◽  
Final Yield ◽  
Flower Thinning ◽  
Stimulation Of

Preharvest fruit splitting (PFS) is a serious problem in Ellendales, especially in hot, humid climactical areas. In control unsprayed treatments PFS can vary from 14 to 30% of the final yield. Any treatment during the fullbloom (FE) period aimed at increasing fruit set (gibberellic acid (GA) sprays, girdling), increases PFS levels, ranging from 40 to 60% of the final yield. This relates to a significant shift (delay) in the normal fruit drop pattern as compared to untreated trees.We have evaluated various approaches aimed at reducing PFS in Ellendales: potassium treatments, from 10 weeks pre-blossom to six weeks after full-bloom, however, increased PFS levels, possibly due to increasing the initial fruit set levels; flower thinning, both chemical and mechanical, marginally reduced PFS, without adversely affecting yield; post-November drop GA application, 2,4-D and girdling treatments, aimed at stimulation of rind growth (not quantified) increased yields significantly (P<0.05) without concurrent increases in PFS.Cross pollinated trees, and resultant high seed content in the fruit, yielded fruit with thicker rinds, with little or no PFS. GA application at FE reduced fruit seed content and peel thickness and increased PFS.Any treatment causing high initial fruit set increases PFS. Flower: flower and fruit: fruit competition should be reduced early during the fruit growth phase, without adversely affecting final yields.

Thinning response of ‘Redhaven’ peaches to 1-aminocyclopropane carboxylic acid (ACC)

2020 ◽  
pp. 1-13
Author(s):  
John A. Cline ◽  
Catherine J. Bakker ◽  
Amanda Beneff
Keyword(s):  
Carboxylic Acid ◽  
Fruit Set ◽  
Total Yield ◽  
Fruit Size ◽  
Fruit Weight ◽  
Full Bloom ◽  
Fruit Thinning ◽  
Leaf Yellowing ◽  
Peach Trees ◽  
Fruit Load

Peach trees bear an abundance of flowers which produce a surplus of fruit that the tree is unable to support. A self-regulatory mechanism enhances the abscission of immature fruitlets leading to a reduced fruit load, but this is often insufficient to achieve fruit of marketable size. Supplementary manual fruit thinning is typically required to optimize economic fruit load. This 2-yr study investigated the response of ‘Redhaven’ peach trees to sprays of 300 and 600 mg L−1 1-aminocyclopropane carboxylic acid (ACC) during the phenological stages of full bloom, shuck split, and ∼20 mm fruitlet diameter. The objective was to determine the efficacy of ACC on fruit set, fruit size, and yield at harvest and the amount of hand-thinning required at “June drop”. Although the response to ACC varied between the 2 yr, 600 mg L−1 ACC spray at full bloom (2018) and at ∼20 mm fruit size (2019) reduced fruit set, the need for hand-thinning by 59%–66%, and crop load. Treatments also had varying but significant effects on leaf yellowing and leaf drop when measured shortly after application. ACC reduced total yield and number of fruit per tree in both study years and increased fruit weight in 2019. Overall, peaches were responsive to ACC at a range of timings from bloom to ∼20 mm fruit size. This study enhances our understanding of ACC on fruitlet abscission of peaches and is one of few studies to demonstrate the effectiveness of a chemical fruitlet thinner for peaches.

Sign in / Sign up

Export Citation Format

Share Document