Effect of zinc sulphate fertilizer rate on the breakage susceptibility of three wheat varieties

Mechanical damage of seeds due to harvest, handling and other process is an important factor that affects the quality and quaintly of seeds. Seed damage results in lower grain value, storability problem, and reduces seed germination and seedling vigor and subsequent yield of crops. The objectives were to determine the effect of different levels of zinc sulphate fertilization on the breakage susceptibility of three irrigated wheat varieties (Bahar, Shiraz and Pyshtaz). An experiment was conduct at the Experimental research station of Lorestan University, Iran. A factorial experiment was conducted with three replicates in a completely randomized block design (CRBD). Factors included three levels of zinc sulphate. Zinc sulphate treatments were combinations of three fertilization rates (0 - control, 25 and 50 kg/ha) at three replicates. The harvested seeds were subjected to impact energies of 0.05 and 0.1 J at constant moisture contents of 9.8, 15 and 20% using an impact test apparatus. The analysis of variance showed that wheat variety, fertilization level of zinc sulphate and moisture content significantly influenced breakage susceptibility of wheat seeds at the 1% probability level. Resistance to the breakage of wheat seeds for all varieties increased, as polynomial functions, with increase in the zinc sulphate rate. The average values of percentage breakage of seeds decreased from 37.07 to 27.80% as the fertilization level of zinc sulphate increased from 0 to 50 kg/ha. Bahar variety exhibited the highest resistance to breakage than other varieties. As the moisture content increased from 9.8 to 20% the percentage breakage of seeds decreased from 36.58 to 30.03%. Increasing the impact energy from 0.05 to 0.1 J caused an increase in the percentage breakage of seeds from 16.19 to 50.47%.