Sanjeev Kumar ¹, J. P. Upadhyay ², Archana Rani ³

Affiliations
1 College of Agriculture, Jawaharlal Nehru Krishi Vishwavidalaya, Ganj Basoda, Vidisha 464221, Madhya Pradesh, IN
2 Department of Plant Pathology, Trihut College of Agriculture, Rajendra Agricultural University, Dholi 843121, Muzaffarpur, Bihar, IN
3 Department of Genetics and Molecular Biology, Rajendra Agricultural University, Pusa 848125, Bihar, IN

Abstract

One isolate each of Trichoderma viride, Trichoderma harzianum and Trichoderma virens were evaluated against twelve isolates of Fusarium udum collected from different districts of Bihar, Jharkhand and West Bengal by dual culture technique. All the bioagents inhibited the growth of F. udum in vitro. Dholi isolate of T. harzianum inhibited the growth of F. udum isolates Fu-5, Fu-12, Fu-14, Fu-21, Fu-24, Fu-27 and Fu-43 by 40.8, 74.5 , 49.4, 59.1, 60.5, 40.8 and 57.8 per cent, respectively and proved superior to other antagonists. T. viride was found to have potential in inhibiting the radial growth of F. udum isolates Fu-29, Fu-37, Fu-49 and Fu-57 while T. virens was more effective in inhibiting the growth of Fu-61. Combined application of T. harzianum and T. viride as seed treatment and soil application gave minimum disease incidence (26.4%) and maximum disease control (56%) followed by 54% disease control in T. harzainum seed treatment and soil application. However, these two treatments were on par with each others. The results also revealed that soil application of bioagents was more effective than seed treatment.

Keywords

Fusarium udum, Pigeonpea, Trichoderma Spp, Wilt.

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H. C. Lal ¹, J. P. Upadhyay ¹

Affiliations
1 Department of Plant Pathology, Tirhut College of Agriculture, Dholi, Muzaffarpur 843 121, Bihar, IN

Abstract

Three blocontroi agents, Trichoderma viride Kifai, Trichoderma harzlanum Rifal and Gliocladium virens Miller, Gidden and Foster were evaluated against Alternaria tenuissima (Kunze ex. Pers.) Wiltshire, the cause of leaf blight in pre-rabi pigeonpea [Cajanus cajan (L.) Milisp.] in vitro and under field conditions. In dual culture, T. viride overgrew the colony of A. tenuissima within 72 hours of incubation followed by G. virens and T. harzianum, which took more than 96 hours to completely overgrow the colony of test fungus. The radial growth of T. viride was more in mono and dual culture than G. virens and T. harzianum. Microscopic examination revealed that T. viride caused lysis and protoplasmic disintegration of the mycella of A. tenuissima. Under field conditions, two sprays of T. viride @ 4g/l water gave 35.59 per cent control of leaf blight of pigeonpea followed by G. virens which showed 31.32 percent disease control.

Keywords

Alternaria tenuissima, Biocontrol, Gliocladium virens, Pigeonpea, Trichoderma viride.

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A. K. Patibanda ¹, J. P. Upadhyay ², A. N. Mukhopadhya ³

Affiliations
1 Agricultural Research Station, Tandur 501 141, Ranga Reddy District, Andhra Pradesh, IN
2 Department of Plant Pathology, Tirhut College of Agriculture, Dholi, Rajendra Agricultural University, Muzaffarpur 843 121, Bihar, IN
3 151, Akansha, Udyan-II, Raibarcilly Road, Lucknow 226025, U. P., IN

Abstract

Trichoderma harzianum Rifai application either to soil as wheat bran saw dust (WBSD) preparation or on the groundnut seeds as spore coat proved effective against selerotium wilt caused by Sclerotium rolfsii Sacc. Synergistic and positive effects on disease control were registered when T. harzianum-WBSD preparation was applied to soil in integration with Vitavax or Vitavax-200. Integration of Thiram (seed coating) and soil application of antagonist was found compatible and synergistic. However, seed treatment with both antagonist and Thiram was found incompatible and hence may not be practically feasible for disease reduction.

Keywords

Biocontrol, Fungicides, Groundnut, Integration, Sclerotium rolfsii, Trichoderma harzianum.

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P. K. Mukherjee ¹, J. P. Upadhyay ², A. N. Mukhopadhyay ¹

Affiliations
1 Department of Plant Pathology, G. B. Pant Universtiy of Agriculture and Technology, Pantnagar - 263 145, IN
2 Department of Plant Pathology, Tirhot College of Agriculture, Rajendra Agri.Univ. Dholi, Bihar, IN

Abstract

Out of eight antagonists, one isolate of Trichoderma harzianum exhibited fastest growth rate and strong antagonism against Pythium apanidermaium in vitro. The prinicpal mechanism of antagonism was direct parasitization of Trichoderma by coiling around the hyphae of Pythium leading to digestion of protoplasmic contents and lysis. Occasional presence of Trichoderma in the lumen of Pythium hyphae was also recorded. Soil application of wheat bran saw dust (WBSD) preparation of Trichoderma gave 32.4 to 77.0 percent control of damping-off under glass house conditions. Seed coating with Trichoderma (1.6 × 10¹⁰ spores/ml) resulted in 31% control of the disease. WBSD preparation of T. harzianum; either live or killed, promoted the growth and vigour of cauliflower seedlings. Apron at 5 and Thiram at 100 μg/ml proved better and completely inhibited the radial growth of P. ahpanidermatum in vitro. None of the fungicides was found inhibitory to T. harzian am except Thiram. Seed treatement with Apron, Fytolan, SAN 506 F and Thiram gave 15.7 to 85.8% disease control. Integration of fungicidal seed treatment with soil application of T. harzianum resulted in 66.4% to 90% control of damping-off. Colony forming units of Trichoderma and Pythium monitored on selective media revealed that the population of Trichoderma remained almost stable where it was applied at higher rates but declined with time in lower rates of application. On the other hand, the population of Pythium declined in Trichoderma amended soil.

Keywords

Biocontrol, Damping-Off, Cauliflower, Pythium, Trichoderma.

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