The external glutamic acid application results in significant effects on some characteristics of sunflower (Helianthus annuus L.)

Abstract

The present study was conducted to determine the effects of glutamic acid treatments at different doses on determined characteristics of some sunflower varieties. Glutamic acid treatments were practiced as foliar sprays at four different concentrations (0, 100, 200 and 300 mg l-1) to three different sunflower varieties (Sakha, Amar and Ishaqi-1). Field experiments were conducted in randomized blocks in a split-plot experimental design with three replications under Anbar-Iraq conditions in 2021. The highest average leaf area index was 5.82 cm2. The 100 mg l-1 glutamic acid treatments of the variety Aqmar yielded the highest chlorophyll content (40.51%). For the variety Ishaqi-1, the 100 mg l-1 glutamic acid treatment resulted in the highest protein content (15.51%). However, the 200 mg l-1 glutamic acid treatments of the variety Ishaqi-1 resulted in an increase in empty seeds rate (75.29%) and oil content (44.09%). In general, medium external glutamic acid doses (100 mg l-1 and 200 mg l-1) increase the chlorophyll content and protein content, and oil content, respectively. But, the empty seed rate also increased with 200 mg l-1 application.