scholarly journals Carbohydrate content in branches and abscission of fruit of peach trees subjected to chemical thinning

Author(s):  
Caroline Farias Barreto ◽  
Roseli de Mello Farias ◽  
Renata Diane Menegatti ◽  
Renan Ricardo Zandoná ◽  
Carlos Roberto Martins ◽  
...  

Abstract The objective of this work was to evaluate the effect of chemical thinning with metamitron on fruit of the Maciel and Sensação peach (Prunus persica) tree cultivars, as well as to identify its relation to the carbohydrate content in their branches. The experimental design was randomized complete blocks, and the treatments were trees with no thinning, manual fruit thinning, and chemical thinning with 200 mg L-1 metamitron applied at 20, 40, and 60 days after full blooming. The evaluated variables were: abscission percentage, yield per plant, number of fruit, presence of lignin in fruit, and carbohydrate content in the branches. The carbohydrate content was evaluated in trees with and without chemical thinning seven days after the application of the product. The use of metamitron promotes fruit thinning in the ‘Maciel’ and ‘Sensação’ peach trees, with a decrease in the carbohydrate content in their branches. Metamitron application 20 and 40 days after full blooming favors fruit abscission in both studied cultivars.

2017 ◽  
Vol 52 (11) ◽  
pp. 1006-1016 ◽  
Author(s):  
Paula Duarte de Oliveira ◽  
Gilmar Arduino Bettio Marodin ◽  
Gustavo Klamer de Almeida ◽  
Mateus Pereira Gonzatto ◽  
Daniel Chamorro Darde

Abstract: The objective of this work was to evaluate the effect of shoot heading and of hand thinning in different development stages of flowers and fruits on the fruit production and quality of 'BRS Kampai' peach (Prunus persica) trees. The experiment was performed during three crop years, under the conditions of the “Depressão Central” region in the state of Rio Grande do Sul, Brazil, and the treatments were: T1, heading of half of the mixed shoot; T2, heading of one third of the mixed shoot; T3, flower thinning in the pink bud stage; T4, thinning at full bloom; T5, thinning of fruit with 5 mm; T6, thinning of fruit with 20 mm; and T7, no thinning or heading (control). Fruit production and quality were evaluated. Plants with no thinning were more productive, but showed high frequency of fruits with a diameter smaller than 60 mm. Shoot heading reduced production per tree and resulted in small-sized fruit. Thinning time did not affect production, and fruit size was greater when thinning was performed at the bloom stage. 'BRS Kampai' peach trees can be thinned starting at bloom, which provides greater fruit size, with no production loss.


2000 ◽  
Vol 80 (1) ◽  
pp. 129-136 ◽  
Author(s):  
Françoise Lescourret ◽  
O. Inizan ◽  
M. Génard

This study attempted to explain peach abscission and early growth variabilities. We assumed that flower anthesis variability was indicative of early competition for carbohydrates, presumedly determinant for fruit set and early growth. From this viewpoint, the fruits resulting from early flowers should be advantaged. In a first step, we described and analysed the pattern of flowering dates within peach trees. In a second step, we studied the relationship between this pattern and the variability of fruit abscission and growth. At the tree level, the flowers started opening from the base towards the top, but at the shoot level the flowers opened from the apex down to the base. Single flowers opened 1 d earlier than associated flowers, which opened independently. However, the relationships between either fruit set or growth and date of flowering did not fit our hypothesis. For example, fruits from the late flowers had the best set. Thus, the initial hypothesis should be rejected while the influence of other factors should be considered. Our observations suggest that post-bloom temperatures could affect fruit set and early growth. Key words: Peach, Prunus persica, flowering, fruit abscission, fruit growth, early stage of development


HortScience ◽  
1990 ◽  
Vol 25 (2) ◽  
pp. 172-173 ◽  
Author(s):  
Edward F. Durner

`Redhaven' peach trees [Prunus persica (L.) Batsch.] on their own roots or budded to seven rootstock [`Bailey', `Siberian C', `Lovell', `Halford' (seedlings), GF 655.2, GF 677 (`Amandier'), or `Damas' (GF 1869) (clonal)] were evaluated for rootstock influence on flower bud hardiness, live pistils at bloom, thinning requirements, marketable yield, and production efficiency after exposure to temperatures lower than – 23C in 1987 and to - 26C in 1988. In 1987, flower bud hardiness was as great on `Siberian C' as on own-rooted `Redhaven' and greater than on the other rootstock. Fewer live pistils were observed during bloom on GF 677 than on `Siberian C', `Lovell', `Damas', or self-rooted trees in 1987. In 1988, flower bud hardiness was greater on `Siberian C' and `Bailey' than on GF 677. At bloom, `Lovell' and `Siberian C' rootstock carried more flowers with live pistils than `Damas'.`Siberian C' and `Lovell' required significantly greater fruit thinning than all other rootstock and self-rooted trees. GF 677 produced a larger marketable crop than GF 655.2 or `Damas'. In addition, `Bailey', `Lovell', and self-rooted trees produced a significantly larger crop than `Damas'. No significant rootstock effect on production efficiency was detected in either year. Tree vigor during the growing season preceding each freeze did not significantly influence flower bud survival or productivity.


Author(s):  
Roseli de Mello Farias ◽  
Caroline Farias Barreto ◽  
Renan Ricardo Zandoná ◽  
Carlos Roberto Martins ◽  
Paulo Mello-Farias ◽  
...  

Abstract: The objective of this work was to evaluate the effect of thinning with metamitron on the fruit yield and quality of 'BRS Kampai' peach (Prunus persica) trees. The experiment was carried out in the municipality of Eldorado do Sul, in the state of Rio Grande do Sul, Brazil, in the 2016 and 2017 crop years. Treatments consisted of the application of 100, 200, 300, and 400 mg L-1 metamitron and of hand thinning 40 days after full bloom, besides control plants. Fruit abscission, effective fructification, number of fruits, and fruit yield per plant were evaluated. Regarding fruit quality, fresh fruit biomass, epidermis color, pulp firmness, soluble solids, total phenolic compounds, and antioxidant activity were assessed; fruits were also classified into diameter classes. For fruit abscission, the effect of the application of 100 mg L-1 metamitron is similar to that of hand thinning. Fruit yield and mean mass in all treatments with metamitron are similar to those obtained by hand thinning. The application of metamitron does not affect the fruit quality of peach trees. Chemical thinning with metamitron may be an alternative to hand thinning in peach trees used for the production of fruits for fresh consumption.


2010 ◽  
Vol 20 (6) ◽  
pp. 983-990 ◽  
Author(s):  
Gerardo Lopez ◽  
Romeo R. Favreau ◽  
Colin Smith ◽  
Theodore M. DeJong

L-PEACH is a computer-based model that simulates the growth of peach [Prunus persica (L.) Batsch] trees. The model integrates important concepts related to carbon assimilation, distribution, and use in peach trees. It also includes modeling of the responses to horticultural practices such as tree pruning and fruit thinning. While running L-PEACH, three-dimensional (3D) depictions of simulated growing trees can be displayed on the computer screen and the user can easily interact with the model. Quantitative data generated during a simulation can be saved to a file or printed for visualization and analysis. L-PEACH is a powerful tool for understanding how peach trees function in the field environment, and it can be used as an innovative method for dissemination of knowledge related with carbohydrate assimilation and partitioning. In this study, we describe the version of L-PEACH that runs on a daily time-step (L-PEACH-d) and how users can run the model and interact with it. To demonstrate how L-PEACH-d works, different pruning and fruit thinning strategies were analyzed. Regarding pruning, model outputs showed 3D depictions of unpruned trees and pruned trees trained to a perpendicular V system. For the fruit thinning studies, we simulated different intensities and dates of fruit thinning in mature peach trees. Total simulated yield increased with crop load but the opposite was observed for average fruit weight. An optimal balance between simulated total yield and average fruit weight was obtained by leaving 150 fruit per tree. Simulating different dates of fruit thinning indicated that fruit weight at harvest was higher on earlier compared with later-thinned trees. The model indicates that fruit thinning should be therefore carried out early in the season to maximize fruit size. The simulation results demonstrate that L-PEACH-d can be used as an educational tool and facilitate the adoption of suitable cultural practices for efficient production.


2020 ◽  
Vol 36 (6) ◽  
Author(s):  
Roseli de Mello Farias ◽  
Caroline Farias Barreto ◽  
Renan Ricardo Zandoná ◽  
Carlos Roberto Martins ◽  
Paulo Celso de Mello Farias ◽  
...  

Peach tree thinning, which aims at reducing plant load so as to ensure productivity and fruit quality, has been manually carried out within a short period of time in the stage of fruit development. Due to the need and shortage of qualified man power, chemical thinning is one of the alternatives that can solve these difficulties found in manual thinning. This study aimed at evaluating the effect of different products which have been applied – either alone or in combination – to fruit thinning of peach tree cultivars ‘Sensação’ and ‘Maciel’ in Pelotas, Rio Grande do Sul (RS) state, Brazil. The experiment was conducted in the 2015/2016 crop in a commercial peach orchard located in Morro Redondo, RS, Brazil. The following seven treatments were carried out 40 days after full bloom (DAFB): plants with no thinning, manual thinning, metamitron, benzyladenine, benzyladenine + metamitron, ethephon, ethephon + metamitron. Fruit abscission, effective fructification, number of fruits and production per plant, mean mass and fruit classification into caliber classes, epidermis color, pulp firmness and soluble solids were evaluated. Production and number of fruits per plant decreased excessively, whereas fruits placed in categories of higher caliber increased when ethephon was either used alone or in combination with metamitron. When both metamitron and benzyladenine were applied, either alone or in combination, they led to fruit abscission and resulted in mean fruit size and weight, at harvest time, similar to those found in manual thinning. Application of chemical products – either alone or in combination – may be an alternative of peach tree thinning in orchard management.           


HortScience ◽  
1994 ◽  
Vol 29 (8) ◽  
pp. 850-853 ◽  
Author(s):  
D. Michael Glenn ◽  
Donald L. Peterson ◽  
Daniela Giovannini ◽  
Miklos Faust

Hand-thinning (Prunus persica L. Batsch) “Y”-trained peach trees at bloom and 51 days after full bloom (DAFB) was compared to mechanical fruit thinning 51 DAFB using a spiked-drum and an impact shaker. The spiked-drum shaker removed more fruit from horizontal branches than from vertical branches, yet did not selectively remove either large or small fruit. Bloom thinning by hand increased fruit size compared to postbloom thinning 51 DAFB, and both postbloom mechanical thinning techniques were as effective as postbloom hand thinning. The spiked-drum shaker may be a better thinning technique than the impact shaker because it transfers less shaking energy to the fruit, can be used in high-density plantings, and does not contact the trunk, lessening the potential for tree damage.


1994 ◽  
Vol 8 (4) ◽  
pp. 840-848 ◽  
Author(s):  
Chester L. Foy ◽  
Susan B. Harrison ◽  
Harold L. Witt

Field experiments were conducted at two locations in Virginia to evaluate the following herbicides: alachlor, diphenamid, diuron, metolachlor, napropamide, norflurazon, oryzalin, oxyfluorfen, paraquat, pendimethalin, and simazine. One experiment involved newly-transplanted apple trees; the others, three in apple and one in peach trees, involved one-year-old trees. Treatments were applied in the spring (mid-April to early-May). Control of annual weed species was excellent with several treatments. A broader spectrum of weeds was controlled in several instances when the preemergence herbicides were used in combinations. Perennial species, particularly broadleaf species and johnsongrass, were released when annual species were suppressed by the herbicides. A rye cover crop in nontreated plots suppressed the growth of weeds. New shoot growth of newly-transplanted apple trees was increased with 3 of 20 herbicide treatments and scion circumference was increased with 11 of 20 herbicide treatments compared to the nontreated control. Growth of one-year-old apple trees was not affected. Scion circumference of one-year-old peach trees was increased with 25 of 33 herbicide treatments.


1993 ◽  
Vol 73 (3) ◽  
pp. 847-855 ◽  
Author(s):  
H. A. Quamme ◽  
R. T. Brownlee

Early performance (6–8 yr) of Macspur McIntosh, Golden Delicious, and Spartan apple (Malus domestica Borkh.); Fairhaven peach [Prunus persica (L.) Batsch.]; Montmorency sour cherry (P. cerasus L.); and Lambert sweet cherry (P. avium L.) trees, tissue cultured (TC) on their own roots, was compared with that of the same cultivars budded on commercially used rootstocks. TC trees of all apple cultivars were similar in size to trees budded on Antonovka seedling or M.4 and exceeded the size of trees budded on M.26. They were delayed in flowering and in cropping compared with trees budded on M.26 and M.4. No difference in titratable acidity, soluble solids, flesh firmness, weight, flavor, and color between fruit from TC trees and from trees on M.4 and Antonovka seedlings was detected in 1 yr of measurement. However, fruit from TC Golden Delicious was more russeted and fruit from TC Spartan had more soluble solids. The difference in fruit appearance between TC and budded trees may result from a root-stock effect or a difference in budwood source, because Spartan fruit from trees on M.4 was more russeted than Spartan fruit from TC trees, but was not different from Spartan fruit from trees on Antonovka seedling. Trees of Macspur McIntosh on TC M.26 and on stool-layered M.26 were similar in size and yield efficiency. TC Fairhaven was larger in size than Fairhaven on Siberian C seedling, but was less yield efficient. No difference in fruit size, flesh firmness, or color was detected between fruit harvested from peach trees on the different roots. Montmorency and Lambert TC and on F12/1 were similar in tree size, respectively, but Montmorency and Lambert TC were more yield efficient than on F12/1. Fruit of TC Lambert was lighter in color and had higher titratable acidity than that of Lambert on F12/1, perhaps a result of earlier fruit maturity. Key words: Apple, peach, sweet cherry, sour cherry, self-rooted, rootstocks


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