MORPHO-PHYSIOLOGICAL RESPONSES OF WINTER WHEAT (TRITICUM AESTIVUM L.) TO PLANT GROWTH REGULATORS AND NITROGEN APPLICATIONS

Abstract

Wheat lodging is a serious problem in cereal production in many areas. Grain yield reductions almost always accompany lodging, with the magnitude of loss dependent on the cultivar, growth stage and severity of lodging. The synthetic plant growth regulators (PGRs) such as chlormequat chloride (CC), trinexepac-ethyl (TE) can prevent lodging by reducing stem elongation and improving mechanical strength of the stem. A field experiment was conducted during the 2018-2019 growing season at the experimental field of the Agricultural Research and Development Station, located at Turda, to evaluate the effect of TE and CC on winter wheat morpho-physiological traits such as plant height, LAI, numbers of spikes m-2, lodging and grain yield of three winter wheat genotypes that are tall and with a high lodging susceptibility Arieşan, Apullum and Bezostaia, tested at different rates of applied nitrogen fertilizer in combination with foliar treatment with trinexapac-ethyl and chlorocholine chloride sprayed over the foliage. The influence of the TE treatment and CC treatment on the morpho-physiological traits studied in this experience was not the same for all the genotypes. Both PGR decreased plant height, more TE treatment than CC treatment. CC treatment influenced more than TE the increase of LAI and number of spikes m-2, witch leaded to the increase of grain yield where CC treatment was applied.