DOI: 10.36347/sjavs.2015.v02i03.015

Pages: 243-252

The most important prerequisite for good crop production is the availability of good quality seeds of high yielding v--arieties, disease free, adapted to the growing area, and preferred by the farmer. Seed-borne disease refers to the particular plant diseases that are transmitted by seed. Seeds are the most important and cheapest input in crop production as 50 % gain in productivity is attributable to use of improved seeds. The quality of seeds alone is known to account for an increase in productivity of at least 10–15 %. To achieve this high quality, all the factors in production that will affect seed viability, disease free and genetic purity should be taken into account. "Seed quality" can have different meanings, depending on whether the seed is being characterized for sale into the marketplace for feed/food use, or for use as seed to plant. For example, marketplace quality characteristics include colour, shape, size, uniformity, and freedom from debris while planting seed quality include all the above and pest/disease free. Planting seed that is free of seed-borne pathogens is the primary means of limiting the intro¬duction of pathogens, especially new pathogens, into a field. Planting infected seed may also result in widespread distribution of disease within the crop, and allows for an increased number of initial infection sites early from which the disease can spread. Most farmers in Nigeria plant uncertified seed saved from the previous harvest, borrowed from neighbors or purchased from local markets, factors that encourage spread and introduction of new diseases. The success of modern agriculture depends on pathogen free seed with high yielding character and in turn disease management. Infested seeds are responsible for the re-emergence of diseases of the past, movement of pathogens across international borders, or the introduction of diseases into new areas. Considerable attention has been paid to improving the sensitivity and selectivity of seed health