Open AccessChemical thinning of apple blossoms in organic production
Author(s) -
D. Stajnko,
Stanislav Tojnko
Publication year - 2020
Publication title -
glasnik zaštite bilja
Language(s) - English
Resource type - Journals
eISSN - 2584-3265
pISSN - 0350-9664
DOI - 10.31727/gzb.43.6.10
Subject(s) - thinning , sprayer , horticulture , randomized block design , fruit set , agronomy , sunflower , chemistry , biology , botany , pollination , pollen , ecology
An experiment on chemical blossom thinning on apple variety 'Summerred'/M9 was performed in an experimental plantation in Brdo pri Lukovici. Different chemical thinners were applied on apple’s fruitlets in organicproduction. The experiment was designed in 7 randomized block with 13 treatments: 1. unthinned trees (as a control), 2. hand thinning in June,3. 1% NaCl, 4. 1,5% NaCl, 5. 1% CH3COOH, 6. 3% CH3COOH, 7. 3% CaSx, 8. 1% rape oil, 9. 3% rape oil, 10. 3% of sunflower oil, 11. 3% soybean oil, 12. 5% dextrin, 13. emulsifier 100 + OCA 30. Chemical thinners wereapplied in a phenological stage at peak blooming with a manual knapsacksprayer. The best thinning of fruitlets (similar to hand thinned trees)was observed with 3% rape oil, however, relatively strong russeting of fruit skin was detected in this treatment. Statistically significant reduction of final fruit set also occurred when 1,5% NaCl and 3% soybeanoil were applied, but with less fruit russeting.