Articles
The efficiency of ACC in the fruit thinning of MaxiGala apple applied in four stages and five concentrations
Article number
1366_30
Pages
261 – 268
Language
English
Abstract
This study aimed to evaluate the agronomic efficiency and practicality of different doses of ACC (1-aminocyclopropane-1-carboxylic acid) in the chemical thinning of apples (Malus domestica), and its effect on phytotoxicity when applied at petal fall, 8-10 mm, 18-20 mm and more than 25 mm fruitlet diameter.
The experiment was located in an orchard in the city of Caçador, SC, Brazil.
A randomized complete block design was used, with seven treatments and six replications, using MaxiGala. The treatments were: 1) Control (manual thinning); 2) ACC 0.25 kg ha‑1; 3) ACC 0.5 kg ha‑1; 4) ACC 0.75 kg ha‑1; 5) ACC 1.0 kg ha‑1; 6) ACC 1.25 kg ha‑1 and 7) Ethephon 0.5 mL ha‑1. Application time were: end of flowering, 8-10 mm, 18-20 mm and more than 25 mm fruit.
The doses of ACC 1.00 and 1.25 kg ha‑1 applied to the end of flowering provided excessive thinning in the apple tree.
The doses of 0.25, 0.5 and 0.75 kg ha‑1 presented results similar to manual thinning (Control). For applications of ACC to 8-10 mm fruitlets, the dose of 1.25 kg ha‑1 was excessive, but doses of 0.5 to 1.0 kg ha‑1 were effective and superior to the Ethephon treatment.
For 18-20 mm fruits, dosages of 1.0 and 1.25 kg ha‑1 of ACC showed greater efficiency than lower dosages.
Fruits greater than 25 mm in diameter had reduced the percentage of fruit drop compared to previous stages.
As a result, we can conclude that doses of 0.5 and 0.75, 1.0, and 1.25 kg ha‑1 of ACC have agronomic efficacy and recommended for thinning apple cultivar MaxiGala. The dosages depend on the application stage, and doses of 1.0 and 1.25 kg ha‑1 should only be applied in the stages of fruits above 18 mm in diameter.
The experiment was located in an orchard in the city of Caçador, SC, Brazil.
A randomized complete block design was used, with seven treatments and six replications, using MaxiGala. The treatments were: 1) Control (manual thinning); 2) ACC 0.25 kg ha‑1; 3) ACC 0.5 kg ha‑1; 4) ACC 0.75 kg ha‑1; 5) ACC 1.0 kg ha‑1; 6) ACC 1.25 kg ha‑1 and 7) Ethephon 0.5 mL ha‑1. Application time were: end of flowering, 8-10 mm, 18-20 mm and more than 25 mm fruit.
The doses of ACC 1.00 and 1.25 kg ha‑1 applied to the end of flowering provided excessive thinning in the apple tree.
The doses of 0.25, 0.5 and 0.75 kg ha‑1 presented results similar to manual thinning (Control). For applications of ACC to 8-10 mm fruitlets, the dose of 1.25 kg ha‑1 was excessive, but doses of 0.5 to 1.0 kg ha‑1 were effective and superior to the Ethephon treatment.
For 18-20 mm fruits, dosages of 1.0 and 1.25 kg ha‑1 of ACC showed greater efficiency than lower dosages.
Fruits greater than 25 mm in diameter had reduced the percentage of fruit drop compared to previous stages.
As a result, we can conclude that doses of 0.5 and 0.75, 1.0, and 1.25 kg ha‑1 of ACC have agronomic efficacy and recommended for thinning apple cultivar MaxiGala. The dosages depend on the application stage, and doses of 1.0 and 1.25 kg ha‑1 should only be applied in the stages of fruits above 18 mm in diameter.
Authors
J.L. Petri, A.A. Sezerino, M. Couto
Keywords
fruit load adjustment, fruit set reduction, increase fruit size
Groups involved
- Division Plant-Environment Interactions in Field Systems
- Division Temperate Tree Fruits
- Division Temperate Tree Nuts
- Division Tropical and Subtropical Fruit and Nuts
- Division Horticulture for Development
- Division Vine and Berry Fruits
- Division Precision Horticulture and Engineering
- Commission Agroecology and Organic Farming Systems
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