No abstract

Chitosan and its derivatives have been reported as a promising alternative for control of postharvest fungal pathogens. The objective of this study was to evaluate in vitro and in situ antifungal activity of chitosan against Alternaria alternata and Colletotrichum gloeosporioides isolated from decayed apple fruits. The fungi were tested in vitro using PDA medium with three concentrations of chitosan (1, 2 and 3 mg/ml). Fungal growth of the test pathogens was significantly affected by all chitosan doses (P<0.05) after 7 days of incubation at 25°C. Water solution of 3 mg/ml of chitosan inhibited completely the conidial germination of A. alternata and C. gloeosporioides after 18 h incubation at 25°C. The results obtained from biocontrol assay indicate that the inhibition of postharvest decay of A. alternata and C. gloeosporioides was significantly influenced by chitosan concentrations. Disease incidence in chitosan-treated fruit after 7 days incubation at 25°C was significantly lower than in the positive control for both fungi tested (P<0.05). A. alternata and C. gloeosporioides used in this study were progressively inhibited in vitro and in situ with increasing concentrations of chitosan from 1 to 3 mg/ml.

No abstract

Application of three combinations of lactic acid bacteria (Lactobacillus plantarum, Lactobacillus rhamnosus), phototrophic bacteria (Rhodopseudomonas palustris) and yeast (Saccharomyces cerevisiae) with sugar cane molasses, marked as: EM1, EM5 and EM AGRO, against the phytopathogenic fungi of tomato and pepper: Fusarium oxysporum, Alternaria alternata, Botrytis cinerea, Colletotrichum sp., Verticilium dahliae and Pythium aphanidermatum was evaluated in vitro and in vivo. A combination of bacteria and yeast named EM5 showed the highest mycelium growth inhibition against B. cinerea (38.4%) in a double agar diffusion test. In a microdilution test, the combination EM1 showed the highest inhibitory effect on B. cinerea (MIC 1x10-3 ?l/ml), while EM5 showed a similar inhibitory effect towards F. oxysporum, A. alternata and Colletotrichum sp. (MIC 10 ?l/ml). The use of EM1 (in concentrations 10 and 100 ?l/ml) and EM AGRO (10 ?l/ml) is recommended for tomato seedling protection. ??1 (100 ?l/ml), ??5 and ?? AGRO (10 ?l/ml) are recommended for pepper seedling protection.

We surveyed different aspects of the application of agrochemicals (pesticides and foliar non-standard fertilizers) on the nutritive value and other non-yield characteristics of crop plants. The survey was based on results of our own trials and studies conducted by other researchers. Various parameters of plant and seedling growth, and yield, were analyzed, as well as the chemical composition, and energetic and thermodynamic parameters of plants in order to better assess the impact of these agrochemicals on crops. The application of various agrochemicals has been found to affect the germination of seeds produced by treated plants. The most significant and most diverse results have been obtained by analyzing the yield and yield components of many different crops (field crops, fruits, vegetables), as well as their chemical composition (mineral elements, different sugars, secondary metabolites, etc.) in terms of improving their nutritive quality. It was found that in maize seedlings it occurs by changing the content of various elements, as well as polyphenol profiles and thermodynamic parameters, and the effects did not only depend on the dosage of agrochemicals but also on maize genotype. We also found that agrochemicals affected the energetic and thermodynamic parameters of individual maize plants, as well as the parameters of plant growth and yield. It was noticed that these agrochemicals greatly affected the content of microelements, starch and crude proteins in maize and barley, sugar and polyphenol contents in various fruit trees and soybean. We noted that in certain agroecological situations these agrochemicals have led to spectacular magnification of yields of different crops, but there were also situations when they did not have any positive effect on crop yield, which is discussed also in the context of results of other researchers. [Projects of the Serbian Ministry of Education, Science and Technological Development, Grant no. TR 31018, TR 31043 and Grant no. TR 37021]