Growth and yield of barley plants in relation to gibberelic acid under calcareous soils conditions

Abstract

A greenhouse study on the effect of GA on barley cv. 121 indicated that spraying plants with 50 ppm GA increased grain yield and its components. In contrast, spraying with 100 ppm GA vigorously increased plant height (lodging), number of total tillers, dry weight of the shoots and the yield of straw, while grain yield and the weight of 1000 grains significantly decreased. Therefore, the 100 ppm GA treatment was considered excessive. It also seems that the proper time for spraying barley plants with 50 ppm GA is at the second leaf stage, whereas after wards GA prolonged the vegetative phase of the plant.