Effect of foliar application of some amino acids on growth and yield of chickpea (Cicer arientinum L.) under different irrigation regimes

The objective of this study was to investigate the effects of foliar application of amino acids of proline, valine and alanine on some morphological traits, yield and yield components of chickpea (Mansouri cultivar) under different irrigation regimes. Therefore, an experiment was conducted in a randomised completely block design with a split-plot arrangement of treatments in a research farm of the Faculty of Agriculture, Tarbiat Modares University, Iran, during the 2018-2019 and 2019-2020 growing seasons. The experimental treatments included three different irrigation regimes (namely regular irrigation, moderate water stress, and severe water stress) as main plots and different foliar applications of amino acids (including 0.5 g.l-1 of proline+valine, proline+alanine and alanine+valine, 1 g.l-1 of a commercial amino acid from Agrares and two treatments with distilled water and no foliar application) as subplots in three replicates. The results showed that plant height, leaf area, 1000-seed weight, grain yield, chlorophyll a and b content, and total chlorophyll were significantly affected by irrigation regimes, foliar application of the amino acid, and their interaction. The highest grain yield (3924.05 kg.ha-1) was obtained under regular irrigation×foliar application of proline+alanine and the lowest grain yield (687.27 kg.ha-1) was obtained under severe water stress×no foliar application. Moreover, a significant increase of 69% in plant height was observed in the interaction regular irrigation×foliar application of proline+alanine compared to the control treatment. Accordingly, regular irrigation and combined application of the above amino acids (under water stress conditions) are recommended to reduce the adverse effects of drought stress on chickpea (Mansouri cultivar).