Sain S.K.,National Institute of Plant Health Management |
Sain S.K.,ICAR Central Institute for Cotton Research |
Pandey A.K.,National Institute of Plant Health Management
Archives of Phytopathology and Plant Protection | Year: 2016
Three Trichoderma harzianum isolates viz., Th-Sks, Th-Ke and Th-Ar collected from respective states of India viz., Rajasthan, Kerala and Andhra Pradesh were evaluated for the management of six fungal diseases namely damping off, Fusarium wilt, Rhizoctonia wilt, early leaf spot, late blight and Septoria leaf spot in tomato. During in vitro analysis, T. harzianum isolates inhibited the pathogens’ growth. Isolate Th-Sks was the most virulent antagonist against all the test pathogens and exhibited maximum of 79.47% growth inhibition of Phytophthora infestans. Isolate Th-Sks proved most effective at suppression efficacy in the range of 95–100% and 91–100% against all diseases under glasshouse and in the field conditions, respectively. Tomato seeds treatment with isolate Th-Sks also promoted plant height (78.23 cm) and fruits yield (290 g/plant) during field trial and data were found to be not-significantly different from other isolates. Thus, it is concluded that isolate Th-Sks can be utilised as a biocontrol agent for management of fungal diseases in tomato. © 2016 Informa UK Limited, trading as Taylor & Francis Group
Babu S.,Indian Agricultural Research Institute |
Babu S.,ICAR Central Institute for Cotton Research |
Bidyarani N.,Indian Agricultural Research Institute |
Bidyarani N.,ICAR Central Institute for Cotton Research |
And 12 more authors.
European Journal of Plant Pathology | Year: 2015
The performance of cyanobacteria and Trichoderma based biocontrol formulations was evaluated in two cotton varieties (Gossypium hirsutum F1861 and Gossypium arboreum CISA 310). Evaluation of mortality after 4 weeks revealed a significant reduction, particularly in G. hirsutum F1861, with values of 13 % (lower by 2 % over the Trichoderma commercial biocontrol agent). The percent mortality after drenching with the compost tea prepared using respective formulations, ranged from 28 to 75 % in G. arboreum CISA 310, with significantly lower values of 6–37.3 % in G. hirsutum. The Anabaena laxa RPAN8 formulation showed the lowest mortality. The activity of hydrolytic enzymes—β-1, 3 glucanase (EGase EC 188.8.131.52), β-1, 4 glucanase (EGase EC, 184.108.40.206) and chitosanase (EC 220.127.116.11) showed a significant enhancement in the inoculated treatments (T1–T6), with Calothrix sp. being among the top ranked treatments in both varieties. Comparison of DNA fingerprints (HIP-TG profiles) of rhizospheric soil DNA with those of corresponding pure cultures revealed a high degree of similarity, confirming the colonization of inoculated organisms. An amplicon of 1000 bp was observed in the soil metagenomic PCR-DNA profiles from both varieties, which confirmed the presence of an endoglucanase gene. Comparative analyses of responses of the two varieties revealed that Gossypium hirsutum F1861 showed higher values of hydrolytic enzymes and available N in soil. On the other hand, microbial inoculation elicited higher levels of chitosanase and defense enzyme activity in Gossypium arboreum CISA 310. This represents a first report illustrating the significance of varietal responses in cotton in relation to the efficacy of microbial biocontrol formulations and their establishment in the rhizosphere. © 2015, Koninklijke Nederlandse Planteziektenkundige Vereniging.
Blaise D.,ICAR Central Institute for Cotton Research
Indian Journal of Agronomy | Year: 2015
An experiment was conducted at Central Institute for Cotton Research, Nagpur, Maharashtra, to monitor flower and boll production in Bt transgenic cotton (Gossypium hirsutum L.) hybrid (‘RCH 2 Bt. hybrid’) as influenced by climatic factors and conservation tillage practices in selected treatments. Two reduced tillage (RT) systems, with limited soil disturbance in the form of inter-culture operations (RT1) and no soil disturbance (RT2), were compared with the conventional tillage treatment (CT). The tillage treatments comprised subplots with and without green manure. Conservation-tillage treatments had 12–15% more bolls retained on a plant than the conventional tillage. Irrespective of the tillage systems, flower and boll production varied among years. Flower production correlated negatively with the maximum and minimum temperature (P<0.0001) and maximum and minimum relative humidity (P<0.001) during both the seasons. In general, sunshine hours and evaporation rate showed a non-significant positive correlation with flower production. In both the seasons, negative correlation was observed for boll production with maximum and minimum temperature (P<0.0001) and minimum humidity (P<0.40). Boll production correlated positively with evaporation rate, but the relationship was significant in the second season (P<0.01). Boll retention was 54.3% higher in the first season compared to 43.6% in the second season due to lower mean maximum and minimum temperature. In general, temperature, relative humidity and evaporation rate were positively correlated with the number of bolls shed. These results indicate that seasonal variability has a greater impact on flower and boll production, irrespective of tillage treatments. Conservation-tillage systems may modulate and modify the adverse climatic effects such as high temperature and increasing moisture stress. © 2015, Indian Society of Agronomy. All rights reserved.