Radiação da luz UV-C para o controle de manchas foliares na cultura do morangueiro

Abstract

UV-C light with 254 nm radiation is an alternative to eliminate pathogens, without causing contamination and to improve the functional quality of plant protection through abiotic stress. Abiotic stress, favors the activation of metabolisms that attribute the defense functions, through anthocyanins, carotenoids, flavones, flavanols, isoflavones in strawberry cultivation. From these conditions, the objective of this work was to identify the effect of 254nm ultraviolet-C light, to control leaf spots of trefoil, during the vegetative development of the strawberry and to evaluate leaf spots, fresh and dry matter, leaf area, chlorophyll and leaf blade color (visual note scale). For this purpose, the study was based on a completely randomized design with 6 treatments and 5 repetitions per treatment, during 30 days. The treatments consisted of different intensities of UV-C light, being (T1 - 0 kJ m-2; T2 - 1.65, kJ / m-2; T3 - 3.3 kJ / m-2; T4 - 4, 95 kJ / m-2; T5 - 6.6 kJ / m-2 and T6 - 8.25kJ / m-2). In addition, statistical analyzes were performed using regression. The results of the evaluations of leaf spots, fresh and dry matter mass, leaf area and chlorophyll analyze, no different difference between the treatments tested. For leaf blade color, there was a significant difference with the coefficient of determination of R² = 0.97. In conclusion, the efficiency of using UV-C light at the intensities tested to reduce leaf spots in strawberries was not verified, with only changes in the color of the trefoil being perceived.