Trichoderma has gained attention as a promising bio-control agent owing to its effectiveness against a wide array of soil-borne plant pathogens. Successful introduction of bio-control agents to farmers is hindered mostly by unavailability of commercial preparation of Trichoderma bio-inoculate with a considerably higher shelf-life. The objectives of this investigation was to study the shelf-life of T. asperellum in selected liquid-and solid-based formulations and to find the suitability of cattle manure as a multiplication medium. Different carrier material including liquids and solids were tested for preparation of a commercial biological formulation of T. asperellum. The liquid carrier media tested in the present study were 1% sucrose, 1% peptone water, 1% tryptone broth, 1% tryptone soy broth and sterilized distilled water. Talc powder was tested as the solid carrier material. Cattle manure was incorporated with talc-Trichoderma formulation to check the suitability of cattle manure as a multiplying substrate. The initial spore count of each liquid formulation was maintained at 1.0x10 6 cfu/ml. At the end of 4 th week, the mean viable spore counts of the tryptone broth, peptone water and tryptone soy broth used were 7.15x10 6 cfu/ml, 7.26x10 5 cfu/ml and 7.30x10 5 cfu/ml, respectively. From the 4 th week onwards, the viable spore count of those three formulations could not be calculated due to heavy contaminations. In the 1% sugar solution and sterilized distilled water, spores were countable only till the end of 8 th week of preparation and the counts were 2.5x10 4 cfu/ml and 2.6x10 3 cfu/ml, respectively. A talc-based formulation was prepared by mixing T. asperellum spore suspension (1.0x10 8 CFU/ml) with talc powder at three different levels (v/w); 30ml/100 g (T1), 40 ml/100 g (T2) and 50 ml/100 g (T3). Three months after storage, all the three treatments (T1, T2 and T3) yielded mean spore counts of 0.92x10 8 cfu/g, 1.11x10 8 cfu/g and 1.21x10 8 cfu/g, respectively. Talc powder inoculation with cattle manure was done at four different rates, i.e. 10 g/kg cattle manure (C1), 15 g/kg cattle manure (C2), 20 g/kg cattle manure (C3) and 25 g/kg cattle manure (C4). Cattle manure was identified as a potential multiplying substrate of the talc-based formulation of T. asperellum.

An experiment was conducted to evaluate different combinations of biofertilizer and biocontrol agents on the vegetative growth of nursery plants of black pepper (Piper nigrum L.). Treated plants showed a significantly higher (p<0.05) leaf area, shoot height, root volume, shoot dry weight and root dry weight compared to the untreated control. The highest leaf area of 244.47 cm 2 was recorded in black pepper plants treated with Trichoderma sp. and Pseudomonas fluorescens while the lowest (118.82 cm 2 ) was recorded in the untreated control. The highest root volume was recorded in plants treated with Trichoderma spp. The highest shoot height, shoot dry weight and root dry weight were found in plants treated with P. fluorescens. Results showed that the combination of above three organisms has not shown a significant impact on growth (p>0.05) than that of the respective individuals. As certain biological control agents may mechanistically be incompatible, one strain may interfere with the mechanism of the other. Hence, only the mixtures composed of mechanistically compatible strains can give better results in biocontrol and bio-fertilizer activities. The results of the experiment confirmed that black pepper plants treated with different biocontrol agents and bio-fertilizer showed a higher vegetative growth in the plant nursery.

No abstract

No abstract