Ammonium thiosulfate as blossom thinner in 'Maxi Gala' apple trees

Abstract

The objective of this work was to evaluate the feasibility of using ammonium thiosulfate as a chemical blossom thinner in 'Maxi Gala' apple (Malus domestica) trees and its effects on fruit quality. The experiment was carried out in an experimental orchard in the Southern Brazil, in a randomized complete block design, with five replicates. Ammonium thiosulfate was sprayed on the apple trees at the full bloom stage, at 0, 1.5, 2.5, and 3.5%. Evaluations were performed for the effects on crop load, fruit set, yield efficiency, and fruit quality parameters such as weight, shape, total soluble solids, seed number, flesh firmness, color, and russeting occurrence. Ammonium thiosulfate at 2.5% is effective to reduce crop load and to improve fruit quality. The thinning effect of ammonium thiosulfate is not dependent on the weather conditions during the crop season. The rate of 3.5% of ammonium thiosulfate causes overthinning and does not result in the improvement of fruit quality.

Improving of Cherry Fruit Quality and Bearing Regularity by Chemical Thinning with Fertilizer

“…ATS is one of the substances still in use because it is safe for the environment and fruit [84]. This environmental friendly compound is a cheap and easily available foliar fertilizer [85] and shows very good results in the thinning of pome species [86][87][88]. It burns the sensitive parts of flowers and destroys the stigma thus preventing pollen germination and flower pollination [37,85].…”

Princípios Ativos Inibidores Da Germinação in Vitro De Pólen De Macieira Como Potenciais Raleantes De Floração

“…Nesse experimento, o tiossulfato de amônio teve efeito inibitório menor, em relação à calda sulfocálcica, na germinação de pólen de 'Fuji Suprema'; mas para efeitos práticos utilizando-o como raleante de flores à campo, o composto se mostrou efetivo, na mesma dose testada nesse experimento, para diminuir a frutificação efetiva e melhorar a qualidade de frutos de 'Maxi Gala' (MARCHIORETTO et al, 2018).…”

“…Experimentos têm demostrado que nas condições climáticas do Sul do Brasil, os raleantes de floração são efetivos quando aplicados no momento correto, para diversas espécies frutíferas de clima temperado (MARCHIORETTO et al, 2018;CARMINATTI et al, 2018;MARCHIORETTO et al, 2019). Entretanto, ainda não há informações disponíveis a respeito da eficiência de compostos cáusticos, oleosos ou hormonais na inibição da germinação de pólen de macieira 'Fuji'.…”