Articles
Different chemical thinning strategies and their effect on apple production in southern Brazil
Article number
1346_59
Pages
463 – 470
Language
English
Abstract
Currently, in Southern Brazil, one of the main obstacles in apple production is the shortage and high cost of labor.
In addition to high cost, hand thinning is slow and, when finished late, it is less effective to increase fruit size and improve return bloom; however, this practice is still widely used in Brazilian orchards.
The objective of the work was to evaluate different chemical thinning strategies and their effect on apple production.
The work was carried out in Santa Catarina State (28°1630S, 49°5609W, altitude 1,400 m). The orchard was implanted in 2006, with Maxi Gala, grafted on M.9, with 1×4 m spacing.
Three chemical thinning strategies were tested: Naphthalene Acetic Acid (7.5 g 100 L‑1, full bloom) + 6-Benzyladenine (Maxcel®, 200 mL 100 L‑1, 5-8 mm) + Ethephon (Ethrel®, 100 mL 100 L‑1, 15 mm) + hand thinning (20 mm); 6-Benzyladenine (Maxcel®, 200 mL 100L‑1, 5-8 mm) + hand thinning (20 mm); Ethephon (Ethrel®, 100 mL 100 L‑1, 15 mm) + hand thinning (20 mm); the control was hand thinning when fruits reached 20 mm.
The number of thinned fruits and time for thinning 1 ha was determined.
At harvest, the number of fruits per tree, production per tree, and hectare were evaluated; the fruits were classified into size classes.
The time spent to perform the hand thinning was on average 44% less in trees submitted to chemical thinning.
Trees that received NAA + BA + Ethephon + hand thinning showed a reduction in productivity of 24% compared to control.
But in compensation, 82.4% of the fruits were classified as large (≥142 g), while in trees subjected to other thinning strategies, only 51.6 to 55.6% of the fruits were classified as large.
Despite the reduction in yield, the highest profit per hectare was obtained when the chemical thinning strategy was adopted.
In addition to high cost, hand thinning is slow and, when finished late, it is less effective to increase fruit size and improve return bloom; however, this practice is still widely used in Brazilian orchards.
The objective of the work was to evaluate different chemical thinning strategies and their effect on apple production.
The work was carried out in Santa Catarina State (28°1630S, 49°5609W, altitude 1,400 m). The orchard was implanted in 2006, with Maxi Gala, grafted on M.9, with 1×4 m spacing.
Three chemical thinning strategies were tested: Naphthalene Acetic Acid (7.5 g 100 L‑1, full bloom) + 6-Benzyladenine (Maxcel®, 200 mL 100 L‑1, 5-8 mm) + Ethephon (Ethrel®, 100 mL 100 L‑1, 15 mm) + hand thinning (20 mm); 6-Benzyladenine (Maxcel®, 200 mL 100L‑1, 5-8 mm) + hand thinning (20 mm); Ethephon (Ethrel®, 100 mL 100 L‑1, 15 mm) + hand thinning (20 mm); the control was hand thinning when fruits reached 20 mm.
The number of thinned fruits and time for thinning 1 ha was determined.
At harvest, the number of fruits per tree, production per tree, and hectare were evaluated; the fruits were classified into size classes.
The time spent to perform the hand thinning was on average 44% less in trees submitted to chemical thinning.
Trees that received NAA + BA + Ethephon + hand thinning showed a reduction in productivity of 24% compared to control.
But in compensation, 82.4% of the fruits were classified as large (≥142 g), while in trees subjected to other thinning strategies, only 51.6 to 55.6% of the fruits were classified as large.
Despite the reduction in yield, the highest profit per hectare was obtained when the chemical thinning strategy was adopted.
Publication
Authors
L. Rufato, A.F. Brighenti, M.S. De Martin, M.S. Pasa, I. Malohlava, F.R. de Freitas, M. Denchinsky, A.R. Luz
Keywords
Malus × domestica Borkh., 6-benzyladenine, ethephon, naphthalene acetic acid (NAA), hand thinning
Online Articles (107)