ABSTRACT
Nontransmissible seed disorders are nonpathogenic, noninfectious, and may or may not lead to deleterious effects on seeds or seedlings. Nontransmissible disorders are due to a number of factors. Humidity and temperature are environmental factors which have the greatest effect on nonparasitic disorders. The genetic background of a host genotype can give rise to seed abnormalities. Operations such as harvesting, threshing, processing, and postharvest handling may result in mechanical injury to seeds. Wet seeds suffer from impact damage on embryos. Baldhead or snakehead in lima bean seedlings is caused by mechanical impact damage on the embryo during threshing. Mineral deficiencies in soil may result in the poor plant growth and thus poor quality seed in the form of reduced seed size, abnormal seed shape, and low viability. Insects cause distinctive damage to seeds and can be easily detected either by the presence of the insects or damage to the seeds.
