EFFECT OF MICROWAVE TREATMENT ON QUALITY OF WHEAT SEEDS INFECTED WITHFUSARIUM-GRAMINEARUM

The object of this study was to investigate relationships between micr owave operating conditions, degree of inactivation of Fusarium gramine arum in wheat, and resulting seed quality in terms of germination and seeding vigour (% germination times plumule-radicle length in cm). The experiment was a full factorial involving initial seed moisture conte nt (SMC = 8, 14 or 20%), absorbed microwave power (AMP = 0.3, 0.4, 0.5 or 0.6 W/g), and the time microwave power was on in a duty cycle of 1 min (TMP = 20, 30, 40 or 50 s/min), and was replicated twice in time. The results showed that eradication of the pathogen increased with th e total microwave energy imparted, but that seed viability and seedlin g vigour decreased accordingly. The percentage of infected seeds in th e control sets (no microwave treatment) was 36%. Germination of these seeds was 100% and seedling vigour was 838.5. The results indicate tha t the percentage of infected seeds may be reduced to between 4 and 7%, while maintaining a seed germination rate of 85% and a seedling vigou r of 670 (i.e. 80% of control). A greater rang of operating conditions can satisfy these conditions when SMC is 14% rather than 8 or 20%. (C ) 1998 Silsoe Research Institute.