Seed Health Management for Better Productivity - Govind Ballabh ...

(Seed Health Management for Better Productivity)Agronomic Management of Seed QualityR.S. VermaDepartment of Agronomy, G.B.P.U.A.&T., Pantnagar-263145 (Uttarakhand)The quality of the produce has become more important at present in view of consumerawareness and competition in the world market. The quality of the crop produced depends mainlyon the quality of the seed sown. The seed quality encompasses several parameters includingpurity (both genetic and physical purity), germinability and health. Use of assured quality seedensures the product to be true to the type and of good quality. Presence of seeds of othervariety/species and diseased seeds reduces the quality of the product and also its productivity.The product of seed purity and germination percentage determines “pure live seed” content of thelot which is the basis for determining seed rate for a crop. The seed produced should meet aminimum level of seed quality as prescribed in Indian Minimum Seed Certification Standards.There are several factors which determine seed quality.Influence of locationThe location influences seed quality and its productivity by determining micro-climateavailable to the crop which is determined by the soil and atmospheric conditions prevailing atdifferent locations of seed production. Therefore, it is important to know the influence of soil andatmospheric conditions on the quality of seed produced.A. Soil: The soil physical and chemical composition determines suitability for a crop. Only thosecrops which can be successfully grown on a particular soil for grain production will also be suitablefor seed production. The soils incapable of realizing potential of genotype will certainly producelow quality seed. Careful selection of the land can prevent many problems and minimize work ofrouging. The field selected should be free from prohibited noxious weeds, relatively free of otherweeds and volunteer plants. The land to be used for seed production should be free from soilborne diseases and insects infesting the crop.B. Atmosphere: The atmospheric changes associated with site of seed production influenceboth productivity and quality of seed. These include temperature and rainfall/humidity whichinfluence insect, pest and disease of the crop. Light available at a particular location also influenceseed quality.a. Temperature: Temperature plays an important role in quality seed production. Temperatureprevailing during vegetative growth of crop would mainly influence the productivity but temperatureexperienced by the crop during seed filling will greatly influence seed quality. The temperatureshould be moderate at the time of seed development. Too high temperature or frost during seedmaturation is detrimental to seed quality. Tripathi (2003) observed significant reduction in seedindex due to one month delay in wheat sowing due mainly to rise in temperature duringreproductive phase. This resulted in significant reduction of seedling vigour parameters viz. rootlength, root dry weight, shoot dry weight and seedling vigour index. Contrary to this in Kharif- 66 -