​Antagonistic Activity of Panchagavya and Trichoderma spp. against Wilt Complex causing Pathogens of Chickpea (Cicer arietinum L.)

Background: Chickpea wilt complex caused by several soil-borne pathogens is the major yield-reducing malady worldwide. Biological control is one of the best, low-cost and ecologically sustainable method for managing plant diseases caused by soil-borne pathogens. Methods: In this present investigation Panchagavya and Trichoderma spp. were evaluated by following poisoned food technique and dual culture technique against wilt complex causing pathogens i.e. Fusarium oxysporum f. sp. ciceri, Fusarium solani and Macrophomina phaseolina. Result: Among the different isolates of Trichoderma spp. evaluated, Trichoderma viride (AAU isolate) was highly antagonistic to F. oxysporum f. sp. ciceri (52.78%) and F. solani (65.37%) whereas, Trichoderma asperellum (AAU isolate) was highly antagonistic to M. phaseolina (65.93%). Panchagavya at the highest concentration (50%) showed significantly higher efficacy (80.74, 66.62 and 49.67%) in inhibiting the mycelial growth of all three pathogens and at the lowest concentration it was moderately effective.

Integration of salicylic acid, vermicompost and bioagent for effective management of chickpea wilt disease

Aim: The aim of the present study was to evaluate the ability of integration of salicylic acid, vermicompost and bioagent for effective management of chickpea wilt disease. Methodology: The effectiveness of salicylic acid and ZnSO4 unaided and in combination with Plant growth-promoting rhizobacteria (PGPR) and vermicompost were evaluated against Fusarium wilt of chickpea under natural condition. Three sets of experiment with nine treatments were conducted in earthen pots in completely randomized design. Ten seeds of wilt susceptible chickpea variety JG 62 were sown. Twenty-days-old plants were sprayed with salicylic acid (Set I), ZnSO4 (Set II) and distilled H2O (Set III). After 24 hr of foliar spray, the whole set of treatment was inoculated with Fusarium oxysporum f. sp. ciceri inoculums, except uninoculated control. The number of wilted seedlings in each pot for each treatment were recorded at 10, 20 and 30 days post-inoculation (dpi) and compared with uninoculated pots. Results: The combined effect of vermicompost amendment @15% and pre-inoculation treatment of salicylic acid showed 0.00, 6.67 and 6.67% wilt incidence whereas treatments having ZnSO4 as pre-inoculation foliar spray resulted in 0.00, 13.33 and 13.33% wilt incidence at 10, 20 and 30 dpi, respectively. Further, the combined treatment of 15% vermicompost along with seed bacterization and pre-inoculation foliar spray of salicylic acid showed complete protection against F. oxysporum f. sp. ciceri. The beneficial effect of vermicompost and PGPR isolate on root and shoot length, and fresh and dry weight of chickpea plants were also observed. Interpretation: High potential for integrating vermicompost, bioagent and foliar application of salicylic acid to surrogate chemical fungicides for eco-friendly and sustainable management of wilt disease in chickpea.

Construing the Role of Plant Extracts, Fungicides and Bio-agents in Ameliorating Fusarium Wilt Management in Chickpea

Background: Chickpea (Cicer arietinum L.) is the most important leguminous crop around the world. Fusarium wilt incited by Fusarium oxysporum f. sp. ciceris is a major biotic constraint in chickpea production. The present investigation was undertaken to evaluate the efficacy of plant extracts, fungicides and bio-agents against Fusarium oxysporum f. sp. ciceris under in vitro and field conditions. Methods: Plant extracts and fungicides were evaluated using poison food technique while antagonistic activity of bio-agents was studied using dual culture technique under in vitro conditions. Field trials were conducted to evaluate the efficacy of different plant extracts, fungicides and bio-agents against Fusarium wilt at Experimental Area of Plant Pathology, CCS HAU, Hisar.Result: Among thirteen plant extracts evaluated in vitro, neem leaves extract was found to be the most effective in inhibiting mycelial growth of F. oxysporum f. sp. ciceris followed by datura leaves’ and garlic cloves’ extract which were statistically at par. Out of six plant extracts tested against Fusarium wilt under field conditions, seed treatment with extracts of neem and datura leaves at 10% concentration were most effective and curtailed the wilt incidence by 39.02 and 34.14% along with 7.55 and 6.83% enhanced seed yield. Among fungicides, carbendazim 50 WP was the most toxic fungicide in restricting colony diameter of the pathogen with the least EC50 and EC90 values of 1.28 and 15.24 ppm a.i. followed by azoxystrobin 23 SC with corresponding values of 1.57 and 49.16 ppm a.i., respectively. Seed treatment with carbendazim 50 WP and azoxystrobin 23 SC were superior over other treatments and provided 88.41 and 85.98% reduction in disease incidence along with 12.85 and 10.99% higher seed yield over control. Among the bio-agents tested, T. viride and T. harzianum gave the best results in suppressing the pathogen growth in vitro and in minimizing the disease incidence coupled with improvement in seed yield under field conditions. The present study has provided chemical and non-chemical measures for integrated management of chickpea wilt.

Management of Wilt Complex of Chickpea with Seed Biopriming and Soil Application of Trichoderma spp.

Background: Chickpea wilt complex caused by several soil-borne pathogens is a serious biotic constraint for chickpea production.Methods: To find out the effective management of the disease through seed biopriming and soil application of biocontrol agents under in vivo and in vitro conditions experiments were carried out during rabi 2018-19 and 2019-20 at Anand Agricultural University, Anand, Gujarat.Result: Seed biopriming showed a positive impact producing vigorous plant shoot and root system, besides disease control during in vitro conditions. While under in vivo conditions, the pooled results of two years revealed that seed biopriming for 10 h with the suspension of talc-based formulation (2 x 108 CFU/g) of Trichoderma viride or T. asperellum @ 50 g in 250 ml of water/kg of seed followed by soil application of T. viride or T. asperellum enriched FYM (10g/kg FYM) @ 100 g/m2 of soil found significant for the disease management as well as higher yield. The seed biopriming alone control the disease in the range of 23-34% and increased the yield of chickpea by 23-29%. However, combined applications of seed biopriming as well as soil application significantly control the disease in the range of 51-70% and increased the grain yield by 41-51% over untreated control.

Inhibitory Potential of Selected Fungicides and Plant Extracts Against Mycelial Growth of Fusarium oxysporum f. sp. ciceri Causal Agent of Chickpea Wilt

Chickpea wilt is one of the major limiting factors, for low yield of chickpea. In Pakistan chickpea wilt causes 10-50% losses every year. At all concentrations, Carbendazim and Benomyl proved most effective while Acrobat was least effective in suppressing the mycilial growth of the Fusarium oxysporum f. sp. ciceri. However, higher concentration of Acrobat was also slightly effective. Among the plant extracts, higher concentrations of Sufaida and Neem proved to be effective while onion failed to control the colony growth of Fusarium oxysporum f.sp. ciceri at all concentrations.