Fusarium verticillioides is an insidious fungal pathogen of maize associated with diseases such as ear rot and kernel rot. It attacks the phyllosphere region of the maize plant especially on inflorescence and cobs. Thus, this study was conducted to isolate potential phyllosphere colonizing antagonistic microbes for the management of Fusarium ear rot. Four phyllosphere colonizing antagonistic bacteria were found to be effective in suppression of the growth of Fusarium verticillioides. Based on 16S rDNA analysis, these bacterial isolates were identified as Pseudomonas aeruginosa isolate 1, P. aeruginosa isolate 2, Bacillus subtilis isolate and B. amyloliquefaciens. Among these four phyllosphere bacteria tested against F. verticillioides, the maximum inhibition of mycelial growth of F. verticillioides and production of volatile compounds was exhibited by P. aeruginosa isolate 1. Application of P. aeruginosa isolate -1, as seed treatment @ 10 g/kg of seeds, soil application @ 5 g/pot and foliar spray @ 0.2 per cent, recorded the minimum PDI with the maximum disease reduction over control. Thus, the present study showed that P. aeruginosa isolated from agricultural ecosystem could be a potential phyllosphere antagonistic bacterium for the management of maize ear rot disease.
Experiments were conducted to study integrated approach in the management of potato blight. The result showed that T1 treatment (soil application of FYM @ 125gm/pot + waste of mushroom cultivation with Trichoderma harzianum @ 5gm/kg + tuber treatment with Azotobacter @ 5% + foliar spray with Ridomil @ 0.25%) was the best to show minimum disease severity, representing 9.16% as against 76.40% in case of control at 21 days of observation. The treatment also exhibited increased tuber germination and plant height of potato showing the value 100 per cent and 44.5 cm at 30 days age of plant. The maximum number of large size tuber and total yield with 668.6g was also recorded from treatment T1. Thus, integration of FYM + mushroom waste as soil application + bio formulation as tuber treatment + fungicides as foliar spray can be efficiently applied for management of late blight and also get enhanced yield of potato.
The Efficacy of the aqueous crude extract from Calotropis procera Linn. on the growth and production of tomatoes Lycopersicum esculentus Mill. infested by Meloidogyne javanica was investigated. An aqueous crude extract of Calotropis procera Linn. was prepared by soaking 2kg of dried powdered leaf in the ratio of 1:5mg/ml for 24 hours; this was sieved and concentrated with water bath at a controlled temperature of not above 60°C also freeze dried to obtain 487g of the dried crude extract. The plant pot of tomatoes infested with Meloidogyne javanica was treated with different concentration of the extracts. Treatment with 50% concentration of the stock solution of C. Procera showed significant growth and yield of tomato. Plant height was 83.3cm whereas in control it was 68.3cm. Significant differences in all other parameters were also obtained. Plant height at final harvest was 89.6cm as compared to control (74.3cm). A positive effect was seen in reducing the number of nematodes both in the soil and in the root. The treatment showed a root gall index of 2.3 which was lowest as compared to control (7.3). Hence at adequate concentration of C. procera extract it is possible to inhibit the nematode attack in tomato.