No abstract

The effect of two rhizobacteria, Pantoea agglomerans and Bacillus subtilis on parasitism of the rootknot nematodes, Meloidogyne javanica on eggplants was evaluated in laboratory and greenhouse experiments. The impacts of the bacteria application as seed treatment, root dipping, and soil drench on early nematode penetration into plant roots, as well as, on eggplant growth were tested. The number of penetrated second stage juveniles of M. javanica was significantly reduced after P. agglomerans and B. subtilis application at concentration of 10 8 CFU ml-1. P. agglomerans increased the eggplant fresh shoot and root weight following seed treatment. In the greenhouse experiment the bacteria were applied alone and in combination with a carbamate nematicide, Oxamyl (Vydate®). P. agglomerans was able to suppress M. javanica development into plant roots through a first half of eggplant cropping season. At the end of cropping season B. subtilis significantly reduced root gall index and number of nematode juveniles in soil and roots. This bacterium applied in combination with Oxamyl was the most efficient against M. javanica reproduction. Thereby, B. subtilis might be considered as a good candidate for biological or integrated control of the root knot nematodes.

Abstract. Due to the intensive soil exploitation and increased mineral fertilization, the degradation of plant residues in the soil is becoming more difficult and slower over the years. This disturbs the structure of the soil and the nutritional balance and leads to a reduction in soil fertility. To solve the problem, microorganisms capable of degrading plant residues in the soil can be used. The purpose of this study was to investigate the effect of fungi of genus Trichoderma on the biodegradation of wheat straw in the soil by observation of the change in cellulase enzyme activity in the soil and the increase in soil biological activity. The highest basal soil respiration was noted at T2TUR (65.76 µgCO2) and T6 (53.69 µgCO2). During the entire straw degradation period, the highest endoglucanase activity was observed at T4 (285.0 μgGlu) and T6 (275.56 μgGlu), whereas the highest β-glucosidase was noted at T6 (5220.3 μgPNP/g/h) and T1UKR (5020.0 μgPNP/g/h). The presence of cellulose-degrading fungi positively affected the increase in the total amount of microbial biomass at the end of the study period, whereas the amount of Corg was increased in all straw amended variants. At the beginning of the process, CMCase correlated with the microbial carbon (r=0.896 for Cmic) and β-glucosidase activity was closely connected with both soil organic carbon and microbial carbon (r=0.819 for Corg and r=0.866 for Cmic). At the end of the investigated period a stronger correlation with Corg was observed.

Abstract. Cellulases and hemicellulases are amount the main hydrolytic enzymes, involved in the bioconversion