Two chitinolytic bacterial strains, Paenibacillus sp. 300 and Streptomyces sp. 385, suppressed Fusarium wilt of cucumber (Cucumis sativus) caused by Fusarium oxysporum f. sp. cucumerinum in nonsterile, soilless potting medium. A mixture of the two strains in a ratio of 1:1 or 4:1 gave significantly (P < 0.05) better control of the disease than each of the strains used individually or than mixtures in other ratios. Several formulations were tested, and a zeolite-based, chitosan-amended formulation (ZAC) provided the best protection against the disease. Dose-response studies indicated that the threshold dose of 6 g of formulation per kilogram of potting medium was required for significant (P < 0.001) suppression of the disease. This dose was optimum for maintaining high rhizosphere population densities of chitinolytic bacteria (log 8.1 to log 9.3 CFU/g dry weight of potting medium), which were required for the control of Fusarium wilt. The ZAC formulation was suppressive when added to pathogen-infested medium 15 days before planting cucumber seeds. The formulation also provided good control when stored for 6 months at room temperature or at 4 degrees C. Chitinase and beta-1,3-glucanase enzymes were produced when the strains were grown in the presence of colloidal chitin as the sole carbon source. Partial purification of the chitinases, followed by sodium dodecyl sulfate polyacrylamide gel electrophoresis and activity staining, revealed the presence of five bands with molecular masses of 65, 62, 59, 55, and 52 kDa in the case of Paenibacillus sp. 300; and three bands with molecular masses of 52, 38, and 33 kDa in the case of Streptomyces sp. 385. Incubation of cell walls of F. oxysporum f. sp. cucumerinum with partially purified enzyme fractions led to the release of N-acetyl-D-glucosamine (NAGA). NAGA content was considerably greater when pooled enzyme fractions (64 to 67) from Paenibacillus sp. were used, because they contained high beta-1,3-glucanase activity in addition to chitinase activity. Suppression of Fusarium wilt of cucumber by a combination of these two bacteria may involve the action of these hydrolytic enzymes.

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Bacterial stalk rot of maize caused by Dickeya zeae previously known as E. chrysanthemi pv. zeae have economic importance of reduced crop yield up to 98.8%. The disease is more prevalent in rainy season in India. The bacterium prefers high temperature and moisture for their growth result is plant toppled down within week. The pathogen has wide host range (maize, rice, tomato, chilli and brinjal etc.) which help to pathogen for long survival in soil. The bacterium characterized by biochemical and molecular tactics. In present, Pel gene and rDNA specific primers are frequently used for D. zeae characterization. The pathogen significantly controls under in vitro and in vivo condition via bleaching powder (drenching of 100 ppm) and antibiotics. The present studies generated data on pathogen nomenclature, etiology, epidemiology, host range, pathogen survival, biochemical, physiological and molecular characterization, germplasm evaluation and disease management.

Delayed sowing of wheat tends to reduce germination count and number of tillers/unit area because of sharp rise in temperature during tillering phase of the crop and ultimately decrease in yield (Soomro and Oad 2002). Hence, an attempt was made to cultivate weed free late sown wheat by use of fenoxaprop-p-ethyl at different doses in lieu of higher productivity and profitability from rice fallow areas. Field experiment was conducted during Rabi season of 2010-11 at Agronomy Research Farm of N.D. University of Agriculture and Technology, Kumarganj, Faizabad (UP). Ten weed control treatments were consisted in randomized block design with three replications. Soil was slightly alkaline in reaction (7.9 pH), low in organic carbon (0.32%) and low in available nitrogen, phosphorus and medium in potassium. Wheat cultivar 'HUW 234' was sown on 23 rd December with 125 kg/ha of seed at row 20 cm apart at 4-5 cm deep by seed drill. The crop was fertilized with NPK 120-60-40 kg/ha through urea, single super phosphate and murate of potash, respectively. Out of ten weed control treatments, fenoxaprop-p-ethyl 10 EC was applied at different doses viz. 75, 100, 120, 150, 200, 240 g/ha. While market sample of fenoxaprop-p-ethyl 120 g/ha and clodinofop (Topic) were used as standard check Each experiment unit of 5.4 x 5.0 m gross plot size was repeated three times. Treatments were applied as post-emergence at 35 days after sowing (DAS) with the help of knapsack sprayer fitted with flat fan nozzle using 600 liters volume of water. Data on weeds was subjected to square root transformation to normalize their distribution.

Bacterial stalk rot (BSR) of maize caused by Dickeya zeae is an important disease in northwest region of India. In the current study, eighty maize lines were evaluated for resistance against this disease. Of these, 20 were moderately resistant, 25 were moderately susceptible and the rest were highly susceptible to BSR. Six lines from each set were randomly selected. Activities of three antioxidant enzymes, viz. phenylalanine ammonia lyase (PAL), peroxidase (POX) and polyphenol oxidase (PPO) were analysed from these three sets of maize lines representing different levels of resistance. A trend of elevated activity of PAL, POX and PPO was observed in all the three sets of maize lines. The results showed significantly more activity of these three enzymes in moderately resistant than highly susceptible maize lines. The activity of PAL and PPO peaked after 48 hr and of POX after 72 hr of challenge inoculation by D. zeae in all the maize lines. The activity of these enzymes further correlated negatively with disease development. Our results show that PAL, POX and PPO play an important role in contributing towards resistance in maize against BSR. K E Y W O R D Santioxidant enzymes, bacterial stalk rot, Dickeya zeae, maize, resistance