Effect of integrated nutrient management and spacing on seed quality parameters of black gram cv. Lbg-625 (rashmi)

A field experiment was conducted to assess the response of nutrient levels and spacing on seed quality attributes of black gram cv. LBG-625 (Rashmi). Experimental results revealed that fertilizer application of 50:100:100 + Black gram rhizobia (250 g ha-1) + PSB- Bacillus megaterium (250 g ha-1) recorded highest test weight (39.27 g), germination (90.60%), root length (15.77 cm), shoot length (13.43 cm), mean seedling length (29.20 cm), mean seedling dry weight (57.99 mg), seedling vigour index-I (2656), seedling vigour index-II (525), total dehydrogenase activity (0.998), protein content (23.16%), field emergence (86.56 %) lowest electrical conductivity (0.813 dSm-1) were superior over other fertilizer treatments. Among the planting geometry 60 x 10 cm recorded more germination per cent (90.48 %) compared to 45 x 10 cm (87.64 %) and 30 x 10 cm (86.91 %). Interaction of nutrient levels and spacing through the application of 50:100:100 + black gram rhizobia (250 g ha-1) + PSB- B. megaterium (250 g ha-1) with planting geometry 60 x 10 cm recorded more mean seedling length (34.40 cm), mean seedling dry weight (58.30 mg),and field emergence (90.24 %) lowest electrical conductivity (0.776 dSm-1) compared to control. The application of 50:100:100 + Black gram rhizobia (250 g ha-1) + PSB- B. megaterium (250 g ha-1) with planting geometry 60 x 10 cm were considered as seed quality improvement approach in blackgram, therefore conjunctive use of inorganic fertilizers and biofertilizer may be suggested for higher seed quality parameters along with overall betterment of crop

Cultural and morphological studies on Ponnampet leaf and neck blast isolates of Magnaporthe grisea (Herbert) barr on rice (Oryza sativa L.)

The study was carried out to standardize the optimal growth, sporulation and production of perfect stage of pathogen on different media. Among different media used such as Potato dextrose Agar (PDA), Oat meal Agar, Ragi flour agar, yeast extract + 2% soluble starch, Host extract + 2% soluble sucrose agar, Potato dextrose agar + Biotin + Thiamine and Rice flour agar, Oat meal agar and potato dextrose agar was found to be best media for radial growth and sporulation of M. grisea. Maximum conidia length (9.46?m) and breadth (7.36?m) was recorded in Oat meal agar followed by Potato dextrose agar and least conidia length (6.15 ?m) and breadth (5.11 ?m) was recorded in ragi flour media after 20 days of inoculation. Conidial size varied in leaf and neck blast isolates, the maximum mean colony diameter of 88.00mm and 89.16mm in neck and leaf blast was recorded in Oat meal agar respectively. The maximum sporulation mean index was observed in Oat Meal agar of 3.15 ?m in leaf and 3.20 ?m in neck blast was recorded. The best growth of the pathogen was recorded at optimum pH range from 6.0 - 7.0 and temperature of 27oC. Therefore oat meal agar media was found to be best among all the media used for growth, sporulation, conidial size and colony characters of M. grisea

Isolation, identification and molecular characterization of Ralstonia solanacerum isolates collected from Southern Karnataka

Bacterial wilt caused by Ralstonia solanacearum, is the major threat to tomato cultivation in all tomato growing areas of Karnataka.  R. solanacearum was isolated from the infected host plants collected from different locations of southern Karnataka. The identity of the isolates was established using morphological, biochemical, and molecular analysis using species specific PCR primers. The race and biovar specificity of pathogen was determined through pathogenicity test on different host plants and the ability of isolates to use carbohydrates, respectively. Phylotype classification was done by phylotype specific multiplex PCR using phylotype specific primers. All the bacterial isolates showed the characteristic creamy white fluidal growth with pink centre on the Tetrazolium chloride medium. Further, the isolates amplified at 280 bp, which confirmed the identity of pathogen as Ralstonia solanacearum. Our results showed that all isolates belonged to Race 1 of the pathogen. Among different isolates obtained, four isolates each were identified to be Biovar III and Biovar IIIA, repectively, while two isolates were identified as Biovar IIIB. All the ten isolates were affiliated to Phylotype I of Ralstonia solanaceraum species complex. These findings may help in devising the management practices for bacterial wilt of tomato in southern Karnataka