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Effect of the growth retardant cycocel and high doses of nitrogen fertilizer in wheat

 

Abstract

The use of higher levels of nitrogen fertilizer in wheat can maximize grain yield potential. However, in general this practice tend to increase crop risks due to the lack of resistance to lodging in most wheat cultivars available. In this way, the use of growth retardants may improve wheat resistance to lodging and consequently maximize grain yield potential. Also, the effect of growth retardants in wheat grain yield gain has been related to the increase in the number of spikes per unit of area and number of grains per spike. To address that the objective of this study was to evaluate the main causes of the effect of the growth retardant cycocel in arrangements with rates of nitrogen in grain yield. For such purpose, lodging index, plant height, number of spikes per unit of area, number of grains per spike, and grain yield were evaluated in nine wheat cultivars. The data did not show that the use of the growth retardant associated with high rates of nitrogen fertilizer can maximize grain yield. Also, the use of cycocel did not increase the yield components number of spikes per unit of area and number of grains per spike in all studied cultivars. On the other hand, cycocel reduced significantly plant height for all cultivars and lodging for CEP 7672, CEP 14, CNT 8, Minuano 82, RS 4, and BR 4, independently of the nitrogen rates.

 

Index terms: growth retardant; wheat and nitrogen