Fifty‐three commercially grown cultivars and germplasm lines of winter triticale (n = 18), wheat (n = 13), and rye (n = 5) and spring triticale (n = 8), wheat (n = 7) and rye (n = 2) were inoculated at mid anthesis with a spore suspension consisting of a mixture of Fusarium culmorum, Fusarium avenaceum and Fusarium graminearum isolates of known toxinogenic activity. Reactions to Fusarium head blight were measured as disease severity, reductions of kernel number/head, kernel weight/head and 1000 kernel weight, number of Fusarium‐damaged kernels and kernel content of deoxynivalenol (DON) and its acetyl‐derivatives 3‐AcDON, 15‐AcDON, and moniliformin. None of the cereal genotypes was completely resistant to Fusarium head blight. Wheat suffered from the largest kernel weight reductions, and accumulated the largest amounts of deoxynivalenol (up to 39.5 mg/kg) and 3AcDON (up to 6.0 mg/kg) in kernels. Deoxynivalenol was not detected in grain samples of winter rye cv. Dańkowskie Z?ote, and spring rye cv. Ludowe. 15‐AcDON was only detected in genotypes of triticale, and 3AcDON only in a few genotypes of winter wheat and rye. Moniliformin was detected at low concentrations (up to 0.092 mg/kg) in kernels of some genotypes selected for the mycotoxin analysis. A moderately strong Pearson correlation was found between head blight severity parameters and the accumulation of deoxynivalenol and its derivatives in grain of the cereal genotypes studied. Fusarium head blight severity parameters were correlated with the percentage of Fusarium‐damaged kernels and reductions of yield components. However, some head blight‐susceptible genotypes realized their potential yields, but accumulated high levels of mycotoxins in kernels. Both Fusarium head blight resistant and susceptible genotypes of the three cereal species accumulated deoxynivalenol in kernels. This finding suggests that the system regulating deoxynivalenol accumulation may be independent of Fusarium head blight reaction.

Five different isolates of R.Solani collected from Coimbatore, Madurai, Aliyar, Ambasamudrum and Gobi in Tamilnadu were assessed for the production of toxic metabolites. The culture filtrate of each isolate was considered as a toxic sample and was assayed for toxicity by bioassay of seed germination and radicle length of toxin treated rice seeds. All the isolates were found to reduce significantly the germination percentage of rice seeds and also the radicle length in germination seeds as compared to control indicating the presence of some toxic metabolites produced by the pathogen.

The rice varieties IR50 and TKM-9 were raised in the second season favourable for blast. Treatments were in the form of seed treatment, nursery treatment or both in seedling stage and followed by two fungicidal spray in the mainfield at tillering and late booting along with a need based application and a control for comparison. All the treatments were found to be better than the need based and untreated control in recording a lower incidence of blast and a higher yield in both the varieties. It is observed from the present experiment that for susceptible varieties, need based application is not sufficient as it is in par with untreated control in all respects. A minimum protection not only reduces blast, but also helps in increansing the yield, even in a susceptible variety