Abstract
The need to decrease production costs along with the lack of man power in the countryside has asked for cultural practices which lead to these factors, such as thinning. Thus, chemical thinning has been studied as an alternative to fruit manual thinning. Therefore, this study aimed at evaluating the quality of peach tree fruits after chemical thinning with metamitron at different time periods in the south of Brazil. The experiment was carried out in a commercial peach tree orchard with cultivars ‘Maciel’ in Morro Redondo, Rio Grande do Sul state, Brazil, from 2015 to 2016. Treatments consisted in the application of metamitron (doses of 200 mg L-1) on the 20th, 30th, 40th, 50th and 60th day after full bloom (DAFB) and manual thinning on the 40th DAFB. Epidermis color, pulp firmness, ripeness index, soluble solids, titratable acidity, juice pH, total phenolic compounds and antioxidant activity were evaluated. The application of metamitron in peach tree thinning did not affect peach color. Changes in the other variables related to the quality of fruits depended on the application period of metamitron in the thinning process and between crops.
Highlights
In the main regions where peach trees are grown, thinning has been carried out manually between the 40th and the 50th day after full bloom (DAFB) (Oliveira et al, 2017)
The color of peach epidermis was not affected by the period in which metamitron was applied to peach tree thinning in both years under evaluation (Table 1)
There was no difference between the epidermis color of fruits thinned by metamitron and the one of fruits which were manually thinned
Summary
In the main regions where peach trees are grown, thinning has been carried out manually between the 40th and the 50th day after full bloom (DAFB) (Oliveira et al, 2017). E., damaged, small and badly located fruits are eliminated. This practice brings many benefits to peach cultures, it requires much man power, must be carried out in a short period and has high production costs (McArtney et al, 2012; Simões et al, 2013). Peach tree cultivars exhibit high bloom, a fact that results in an excessive number of fruits which is incompatible with the production capacity of the plant (Giovanaz et al, 2016; Barreto et al, 2018). The excessive number of fruits leads to small fruits that have low commercial value (Giovanaz et al, 2016). In order to improve the quality of fruits and increase their commercial value, thinning must be carried out in the orchard (Greene & Costa, 2013; Turk et al, 2014)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
