Escala diagramática e severidade do Paraulaca dives (Germ., 1824) de acordo com o uso de indutores de florescimento em jabuticabeira híbrida [Plinia cauliflora (DC.) Berg]

Abstract

Brazil has several fruit species in its flora, many with commercial potential, such as the Myrtaceae family. In this, there is the hybrid jabuticabeira (Plinia cauliflora) to be of wide territorial coverage plan. The productivity of jabuticabeira is threatened, among other factors, by insects. The green beetle (Paraulaca dives) is one such insect pest that causes loss of leaf area jabuticabeira. However, there are few reports of the occurrence of Pa. Dives and little is known about their habits. Therefore, the assessment of the damage caused by Pa. Dives and development of diagrammatic scale is needed, as it provides greater precision, accuracy and reliability in the assessment of severity. Therefore this study was to evaluate the influence of flowering inducers severity of Pa dives in Jabuticabeira hybrid plants and develop a diagrammatic scale of the damage caused by this insect. For this, jabuticabeira leaves were photographed, the images were analyzed with the help of the Software Image J [marca registada], measuring the actual area and the percentage of damage. To quantify the severity collected up eight high extract of leaves, eight medium-eight sheets under the leaves, and two per quarter, totaling 24 leaves per replicate, each repetition consisted of three plants. We used five treatments of floral induction (calcium carbide, Ethrel, Paclobutrazol, daily irrigation and control) and eight replicates per treatment, totaling 40 repetitions and 960 collected leaves. Was developed and validated a diagrammatic scale with six levels of severity. Scale validation was performed by 10 evaluators, five professionals with experience and five without experience in both evaluations, with and without the use of the proposed scale. It was observed in the low jabuticabaira extract of the leaves of larger size were found in plants treated with calcium carbide (14.29 cm²), Ethrel (14.08 cm²), Witness (13.75 cm²) and Paclobutrazol (12.93 cm²). In the medium extract leaves more area were in treated water (15.14 cm²), calcium carbide (13.16 cm²) and Witness (13.29 cm²), high extract calcium carbide (14.55 cm²), ethephon (13.84 cm²), daily irrigation (13.09 cm²) and Witness (13.78 cm²). The loss of leaf area (%) caused by the attack by Pa. Jabuticabeira dives in leaves treated with Paclobutrazol (21.81%), Ethrel (18.54%) and daily irrigation (16.38%) were higher compared the too much. The accuracy and precision of each rater were determined by percentage between the actual and the estimated severity. It was observed that the evaluators untrained tended to overestimate the actual severity of the lesions caused by value Pa. Dives in the ratings without the use of the scale. In turn, the trained raters obtained similar results when compared to the allocation of your notes using the proposed diagrammatic scale and without using the key. Thus, Pa. dives Food showed preference in hybrid jabuticabaira treated with daily irrigation, ethephon and Paclobutrazol. The proposed diagrammatic scale for assessing the severity caused by Pa. Dives proved to be effective for sheets Pl. Cauliflora.