The evaluation of seed osmopriming and irrigation levels on growth, yield and yield component of wheat (Triticum aestivum L.)

Since water deficit during plant growth period is one of the main important limiting crop yield. An easy and inexpensive way to reduce the impact of water deficiency is essential. Therefore, the aim of this study was to investigate the effect of seeds osmo-priming on growth, yield and yield components of wheat cultivar Anfarm 4 under field conditions, a factorial experiment based on a completely randomized block design with three replications was conducted at Research Field of Agriculture College, University of Birjand in 2017-2018. The treatments consisted of three levels of irrigation (include 100, 75 and 50% of the plant water requirement) and four levels of seed priming (include 0 (control), -0.3, -0.6 and -0.9 MPa induced by PEG 6000). The results of this experiment showed that irrigation levels had a significant effect on measured traits including plant height, tiller number, spike number, spike length, grain number per spike, 1000 seed weight, biological yield, grain yield (P <0.01). However, no significant effect was observed on harvest index. Seed priming had significant effect on plant height and spike length (P <0.01), number of tillers, number of seeds per spike, biological yield, grain yield (P <0.05). Interaction effects showed a significant effect on all of the traits except harvest index. The results of this study showed that the application of osmotic priming seeds -0.3, -0.6, -0.9 MPa resulted in 2.13, 2.62 and 2.15 times of seed yield at 50% water requirement treatment compared to without seed priming treatment. The results of means comparison showed that osmotic seed priming by polyethylene glycol, resulting in a pressure of -0.6 MPa, under 50% of the water requirement treatment showed the highest grain yield compensate ability. However, in 75% of water requirement treatment, pre-treatment had no significant and positive effect on grain yield, even in -0.9 MPa treatment, had a negative and significant effect on seed yield. Therefore, the application of osmotic seed priming somewhat compensated the damage caused by water shortage on grain yield under stress conditions of 50% of water requirement. While in non-stress conditions, osmotic seed priming had no positive effect on grain yield.