a study on the seed susceptibility of wheat (triticum aestivum l.) cultivars to impact damage

mechanical damage due to harvesting, handling, and other processes is an important factor that affects the seeds quality. seed damage results in lower grain value and more storability problem and reduces seed germination and seedling vigor and subsequent yield of crops. tests were conducted to determine the percentage of physical damage (ppd) and percentage of loss in germination (plg) of wheat seeds due to impact. the effect of wheat seed variety and impact velocity was determined. wheat seed varieties selected for testing included: kohdasht, maron, simereh, sardari and zagros. four impact velocities: 10, 20, 30 and 40 m s-1 were used. results showed that effects of impact velocity and seed variety on seed damages were significant. ppd to seeds was higher than plg in higher impact velocities. it found that the total damage of seeds increased from 4.17% (0.48 ppd and 3.68 plg) to 73.32 % (47.59 ppd and 25.73 plg) as impact velocity increased from 10 to 40 m s-1 for all wheat varieties studied. impact results indicated that sardari wheat variety was more susceptible to ppd (27.39 %), while maron seeds were more susceptible to plg (14.70%). among the varieties studied, sardari wheat seeds showed the highest level of total damage i.e.sum of ppd and plg.