EFFECTS OF INSECTICIDE SEED TREATMENTS ON SEED VIABILITY AND VIGOR INWHEAT CULTIVARS

The present study was conducted to determine the effects of seed treat ment with different insecticides and period of storage of treated seed s on standard germination, abnormal seedlings, ungerminated seed, vigo ur index and speed of germination in eight wheat cultivars. Significan t (P less than or equal to 0.05) differences were observed among diffe rent cultivars, insecticides, period of storage of treated seed for al l the parameters of germinability/viability and vigour. Cultivar Sonal ika was most sensitive while HD 2329 was least sensitive to insecticid al seed treatments. Among the four insecticites, Formothion 20EC affec ted all the parameters of viability and vigour in most of the cultivar s, especially in cv. Sonalika. Endosulfan treatment gave results compa rable to the control. Storing the treated seeds for 7 days or more res ulted in adverse effects. The majority of the treated ungerminated see ds at the time of final count (8th day), were found to be viable (TZ t est) which suggests that this test may not be as optimal for heated se eds as it is for untreated ones. Procedures for germination testing of insecticide treated seeds should be studied in more detail. Also, the consequences of delayed germination due to insecticide seed treatment have been discussed.