Growth, Yield and Biochemical Responses in Barley to DAP and Chitosan Application Under Water Stress

The present investigation was aimed at enhancing the quality and productivity of barley by the fertilizer and chitosan application. The field experiments were conducted in the northern region of Jordan, under the rain fed conditions in the main growing seasons of 2014/2015 and 2015/2016. The experiment was conducted in a well-designed split-plot having three replications and two fertilizer levels (0 and 100 kg•ha-1 DAP (Diammonium phosphate 46% P2O5). Chitosan, in three different concentrations (0, 5, and 10 g•L-1), was randomly applied to all fertilized plots as subplot treatments. The results revealed the highest seed dry weight (5.8 g per plant) in the plants treated with 100 kg•ha-1 of DAP, while the lowest (5.2 g per plant) was recorded in the control which exhibited an increase of about 10%. However, other parameters, namely the number of grains, number of spikes, and number of grains were also found to be influenced by the chitosan treatment. Significant variation (P < 0.01) were also high between the lines in the presence and absence of chitosan application. The highest number of grain yield, number of spikes, and grains/spike were found by the foliar treatment of 10 g•L-1 chitosan to barley plants at the tillering stage. Similarly, the grain quality, particularly with respect to protein and starch, was found to be enhanced significantly over control. The highest protein (12.6%) and starch (62.3%) were obtained with 100 kg•ha-1 DAP fertilizer level mixed with 10 g•L-1 chitosan. Hence, based on results, it can be concluded that the fertilizer level 100 kg•ha-1 DAP combined with 10 g•L-1 chitosan is economically best and recommendable for improving the quality and productivity of barley in the northern region of Jordan.