Omari Dangelo Forlin Dildey

Fungitoxicity activity of Phosphorus and Calcarea carbonica against Sclerotinia sclerotiorum and control of white mold in common bean (Phaseolus vulgaris) with extremely diluted aqueous solutions

Common bean (Phaseolus vulgaris L.) is one of the main Brazilian agricultural crops. Numerous diseases have affected such a crop during its life cycle, such as white mold, caused by Sclerotinia sclerotiorum. This fungus is quite aggressive and requires an intensive use of pesticides. This study aimed at evaluating white mold control and antimicrobial activity against S. sclerotiorum using extremely diluted aqueous solutions of Phosphorus and Calcarea carbonica, at 6CH, 12CH, 24CH, 36CH and 48CH dynamizations (centesimal Hahnemannian). The tests were carried out in a completely randomized design, with 10 treatments and 5 replicates each, considering water as control. Variables including disease progression, the number of dead plants, the number of sclerotia, and mycelial growth were evaluated by in vivo and in vitro tests. The treatments Phosphorus 12CH, Phosphorus 48CH, Calcarea carbonica 12CH, and Calcarea carbonica 48CH presented resistance-inducing action by slowing down the disease progression up to 83% and decreasing the number of dead plants up to 90%. In vitro tests showed that the treatments Phosphorus 12CH, Phosphorus 48CH and Calcarea carbonica 48CH slowed down the mycelial growth. The latter also completely inhibited the production of sclerotia. These results indicate the potential of Phosphorus 12CH, Phosphorus 48CH, Calcarea carbonica 12CH, and Calcarea carbonica 48CH for controlling S. sclerotiorum in common beans.

Atividade antioxidante e enzimática em morangos (Fragaria vesca L.) tratados termicamente combinados com ácido salicílico

Postharvest strawberry treatments are needed to induce resistance and increase the shelf life without loss of quality. Therefore, this study aimed to evaluate the effect of postharvest heat treatment in combination with salicylic acid in the antioxidant activity, enzymatic and incidence of fungi in the strawberry during storage. The experimental design was completely randomized in a 4x4 factorial design with four replications. Strawberries grow Dover were subjected to the following treatments: heat treatment (45 ° C for 3 h in an oven), application of salicylic acid (immersion for five minutes in 2.0 mM aqueous solution), combination of heat treatment with salicylic acid and control (untreated). Were stored for 1, 7, 14 and 21 days under refrigeration at 5 ° C with 90-95% relative humidity. The enzymatic activity of peroxidase (POD) occurred in the initial period of 1 to 7 days of storage strawberries treatment heat and with salicylic acid. Regarding the combination of salicylic acid and heat treatment occurred enzymatic activity in the presence of fungi. For polyphenol oxidase (PPO) activity, heat treatment showed an oscillation of activity, while salicylic acid and the combination of and salicylic acid with treatment heat showed no significant differences, and showed constant activity of PFO. For the treatment with salicylic acid the strawberries showed only 5% fungal incidence. The antioxidant activity of strawberries treated with salicylic acid was high in all periods except at 21 days.

Identificação de Alil Isotiocianato em crambe por HPLC

The identification of molecules present in plants by chromatographic techniques such as HPLC, can bring promising alternative to the control of plant diseases, since brassicas have glucosinolates, which act in plant defense. The objective of this work was to verify the presence of allyl isothiocyanate by HPLC (High Performance Liquid Chromatography Reverse Phase), using different methods of extraction. The plant material was leaves of Crambe abyssinica , dried at 45 °C for 48 h. The extraction methods used consisted of 200 mg L -1 of plant material for each method: infusion, aqueous solution, and cetonic, hydroalcoholic, methanol, hexane and chloroform solutions. The identification and quantification were by HPLC on C18 column UV at 244 nm. The experiment consisted of seven treatments with three replicates using the Tukey p <0.05 test. The solvents methanol and hydroalcoholic presented high affinity to molecules of allyl isothiocyanate, and methanol was the best solvent for the extraction, with a concentration of 133.88 mAU. The allyl isothiocyanate was identified at the time of 4.29 min and 4.35 min for methanol and hydroalcoholic extract respectively.