Thumbnail Image

Theses

Browse

2017 - 201912020 - 20211
Reset filters
Subject: Plant Pathology × Author: Khanna, Annie × Start date: 2001 × Type: Thesis ×
Reset filters

Search Results

Now showing 1 - 2 of 2
  • Thumbnail Image
    ThesisItemOpen Access
    Studies on phytobiome, epidemiology and management of chickpea wilt caused by Fusarium oxysporum f. sp. ciceris
    (CCSHAU, Hisar, 2021-04) Khanna, Annie; Kushal Raj
    Present investigation entitled “Studies on phytobiome, epidemiology and management of chickpea wilt caused by Fusarium oxysporum f. sp. ciceris” indicated that early sowing of chickpea in the month of October ameliorate the disease severity in susceptible variety (JG 62 and C 235). Amongst weather variables Tmax, Tmin, and RHM were positively correlated with enhancing disease severity while relative humidity evening, wind, rainfall and rainy days were negatively correlated. On the basis of sequencing of 16S rRNA gene, the chickpea root bacterial endophytes belonged to genera Bacillus sp., Ochrobactrum sp., Luteimonas sp., Pseudomonas sp., Advenella sp., Paenibacillus sp., Cellulosimicrobium sp. and Microbacterium sp. Out of 20 chickpea root bacterial endophytes, CRBE1, CRBE3 and CRBE7 showed maximum antagonistic activity against Fusarium oxysporum f. sp. ciceris under in vitro conditions. The bacterial endophytes viz. CRBE2, CRBE3, CRBE4, CRBE7, CRBE8, CRBE10 and CRBE 17 showed positive reaction for siderophore production while CRBE1, CRBE7 and CRBE9 exhibited positive reaction for HCN production and CRBE1 showed highest growth on ACC supplemented medium. Minimum disease incidence and maximum phenol content (412.70μg/g) was observed in plants of chickpea variety HC 3 raised from seeds treated with CRBE3. Amongst plant extracts neem and datura while among fungicides, carbendazim 50 WP and azoxystrobin 23 SC were found to be best under in vitro and field conditions. Among bio-agents evaluated T. viride and T. harzianum were found to be superior to other bioagents in inhibiting mycelial growth, minimizing disease incidence and increasing seed yield of chickpea variety JG 62. The soil amended with G. mosseae reduced disease incidence and enhanced seed yield and yield attributes viz. number of pods per plant, number of seeds per pod and seed weight in chickpea varieties JG 62 and C 235.
  • Thumbnail Image
    ThesisItemOpen Access
    Studies on variability and management of pearl millet smut caused by Moesziomyces penicillariae (Bref.) Vanky
    (CCSHAU, 2017) Khanna, Annie; Kushal Raj
    Smut of pearl millet incited by Moesziomyces penicillariae (Bref.) Vanky is the most wide spread and destructive disease in India and other pearl millet growing areas of the world. This disease is a major limiting factor in full exploitation of high yielding potential hybrids in India. In the present investigation, during survey the smut severity to the extent of 10 per cent was observed in villages of Hisar, Mohindergarh, Rewari and Bhiwani. Among four isolates of M. penicillariae collected from Hisar, Jaipur, Mandore and Gwalior, there was not much variation in size and shape of sporeball but little variation was observed in size of sporidia and germination per cent. The Hisar isolate of M. penicillariae was found to be most virulent on the four cultivars of pearl millet. The growth of M. penicillariae was maximum at 35˚C on potato dextrose agar (PDA) medium enriched with pearl millet grains and sucrose. Amongst 239 entries of pearl millet screened, 52 entries were free of smut, 93 entries showed smut severity upto 10% and in remaining 94 entries smut severity was 10 per cent and above. Among different fungicides evaluated against M. penicillariae the causal agent of pearl millet smut, carbendazim and copper oxychloride performed better under in vitro and in vivo conditions. Carbendazim was better as prophylactic spray whereas copper oxychloride was better to be used as curative. Among different plant extracts evaluated, aloe vera performed better to manage smut of pearl millet followed by jamun extract as pre inoculation spray.