the Symposium on Wheats for More Tropical Environments - cimmyt

206Results from this field experiment alsoindicate that <strong>the</strong> weight of seeds withblack point per 50 grams of seed wasless with Tilt 250 EC. which gave 3.63grams of seeds with black point. ascompared with 16.44 grams for <strong>the</strong>control (Table 3).The preliminary experiment on <strong>the</strong>effect of rate and frequency of chemicalapplications showed a smaller numberof lesions after spraying with DithaneM-45. as compared with Fungitoxsprayedplants and <strong>the</strong> control.Fur<strong>the</strong>rmore. <strong>the</strong>re was no difference indisease development with one or twospray applications. or at any rate ofapplication; an interaction between rateand frequency was only observed whenDithane M-45 was applied three times.Fungitox seemed to have no effect onhelminthosporium leaf spotdevelopment (Table 4).Homai and Vitavax-thiram. when usedas slurry at 2 glkg of seed, and Vitavaxcaptanand Arasan at 4 glkg. all seempromIsing for protecting seeds againstSclerotium rolfsii. Rhizoctonia solaniand Fusarium moniliforme. ascompared wIth <strong>the</strong> control (Table 5).Tests on <strong>the</strong> eradication of <strong>the</strong> morecommon seed-borne fungI. such asF. moniliforme. Curvularia spp.,Aspergillus spp., Helminthosporiumspp.• Penicillium spp.. Rhizophus spp.and Alternaria spp., using <strong>the</strong> samechemicals. rates and method ofapplication as above. showed that all of<strong>the</strong> chemicals tested were effective ineradIcating <strong>the</strong>se seed-borne pathogenson wheat seeds (Table 6).Table 3. Presence of black point on seeds of wheat variety UPLW2according to fungicide treatR'ent, Los Ballos, Philippines, 1984FungicideTilt 250 ECVinicurOrthocide 50 WPCaltan FManzate 200Manzate DControlAPplicatio~ate(FP/ha}!!0.6 It1.0 It1.5 kg2.0 It2.0 kg2.0 kgSeeds withblack point(g/50g seed)3.64.55.36.16.111.516.4~/ FP = formulated product