Evaluating chemicals for inducing budburst in peach orchard grown in subtropical conditions

Abstract

Chill hour’s availability influence break dormancy, sprouting and production of temperate fruit trees in different regions. Chilling requirements for growing peaches in subtropical regions are limited during winter and some chemicals are necessary for overcoming dormancy and inducing budburst. Therefore, there is a necessity of more information about the use of these chemicals on inducing sprouting in peach trees. This study aimed to assess hydrogen cyanamide, nitrogen fertilizer and calcium nitrate to induce budburst in the ‘Douradão’ peach orchard, located in the subtropical region of São Paulo state, Brazil. Then, tree chemicals were evaluated: 0.6% hydrogen cyanamide; 2.5% nitrogen fertilizer + 4% calcium nitrate; 4% calcium nitrate and control to determine the budburst, flowering and fruit set percentage, flowering period, number of fruits, production per tree and yield. The experimental design was a randomized block, in a split plot arrangement. The plots were represented by inducing sprouting chemicals and subplots for two crop seasons.  The hydrogen cyanamide increased, anticipated and concentrated the flowering of the plants; besides enhancing fruit set and production. Furthermore, nitrogen fertilizer + calcium nitrate also promoted budburst enhancing flowering, production per tree and yield.  The spraying of the peach trees with only calcium nitrate presented a performance like the one observed in the control.  The results allowed indicate the use of hydrogen cyanamide or nitrogen fertilizer + calcium nitrate, as an alternative for inducing budburst in peach trees of Douradão cultivar under subtropical conditions, depending on the adopting orchards system cultivation.