Influence of seed processing methods and seed treatments on seed mycoflora of guinea (Panicum maximum) and para (Brachiaria mutica) grasses

Abstract

A study was undertaken to standardize suitable management strategy of seed borne mycoflora, maintaining the quality of seeds in guinea (Panicum maximum) and para (Brachiaria mutica) grasses. The experiment consisted of two seed processing methods (P1 : sweating method and P2 : non-sweating method) and nine seed treatments (S1 : seed treatment with captan (0.2%), S2 : seed treatment with vitavax power 0.2 % (carboxin + thiram), S3 : seed treatment with tebuconazole (0.2%), S4 : seed treatment with carbendazim (0.2%), S5 : seed treatment with carbendazim + mancozeb (sprint 0.2%), S6 : seed treatment with bioagent- Pseudomonas fluorescens (0.4%), S7 : seed treatment with bioagentTrichoderma harzianum (0.4%), S8 : chemical control (dormancy treated but not with fungicide) and S9 : absolute control (without any treatment). The present study revealed para and guinea grass seeds were associated with different seed mycoflora viz., Aspergillus flavus, Alternaria sp. Curvularia lunata, Bipolaris sp. and Rhizopus sp. Seeds processed by non-sweating method found effective with highest field emergence (25.36% and 14.39%), seed germination (27.78% and 15.01%), seedling dry weight (16.69 mg and 39.50 mg), seedling vigor (395 and 218), thousand seed weight (0.96 g and 3.25 g) and lowest mycoflora incidence (19.45% and 37.64%) in both guinea and para grasses, respectively. Seed treatment with Pseudomonas fluorescens recorded lowest seed mycoflora incidence (13.73%) and highest field emergence (30.18%) in guinea grass and seed treatment with S2 recorded lowest seed mycoflora incidence (25.86%) and highest field emergence (17.26%) in para grass. Seed quality parameters such as thousand seed weight, seed germination, seedling vigor and seedling dry weight were also found highest in the same treatments. Further results indicated that treatment combination of P1 with S2 and S6 in guinea and para grass had positive effect.