EFFECT OF COTTON SEED DELINTING ON SEED-BORNE FUNGI, EMERGENCE AND SEEDLING DISEASE INCIDENCE

Recently, delinted cotton seeds are being widely used. Different insecticides and fungicides were screened-out with delinted and unde‌linted cotton seeds against Rhizoctonia solani under greenhouse .condi‌tions. In the laboratory, undelinted, undressed seeds had all the isolated fungi with the highest frequency while acid delinted seeds dressed with Monceren 47% + Gaucho gave the lowest frequency of isolated fungi. The most prevalent isolated fungi was Aspergillus spp. and the least frequently isolated fungi was Mucor sp. Mechanically delinted seeds, dressed with Monceren 25% gave the highest seedling emergence frequency and the highest percentage of surviving seedling (in infested soil). While acid delinted seeds untreat‌ed with fungicide gave the lowest seedling emergence frequency and the lowest percentage of surviving seedling (in infested soil). Acid delinted seeds dressed with Monceren 25% exhibited the highest speed of germination in non-infested soil, while the lowest speed of germination was obtained from acid delinted without seed dressing in infested soil. Seeds dressed with Monceren 25% gave the largest plant heights when it was mechanically delinted and grown in non-infested soil, while it gave the lowest plant heights when acid delinted and grown in infested soil. Undressed mechanically delinted seeds grown in non-infested soil exhibited the highest dry weight. Acid delinted, untreated seeds grown in infested soil gave the lowest dry weight. A positive significant correlation coefficient was found between frequency of Penicillium spp. and percentage of infection.