Correlation Among Damages Caused by Yellow Beetle, Climatological Elements and Production of Guava Accesses Grown in Organic System

Abstract

-The objective of this research was evaluate the damage caused by the yellow beetle on 85 guava accessions and correlations of the damage with the climatological elements and the production of fruit in an orchard of guava conducted in organic system. Ten leaves by access were analyzed containing the injury of insect attack. Each leaf had its foliar area measured by leaf area meter and, after obtaining the total area, the leaf was covered with duct tape, and measure again. The averages were compared by Scott-Knott test at 5% probability. The 15 accessions with highest average damage had the data submitted to the correlation with the minimum and maximum temperature, precipitation and relative humidity. The production was obtained by the number of fruits/plant. The damages are negatively correlated with the mean relative humidity of 7:00h (local time) in the period of 14 days prior to the assessments, and negatively affect production. The accessions Saito, L4P16, Monte Alto Comum 1 and L5P19 are promising in organic agriculture, for presenting good production and minor damage to insect attack, when compared to others. Index terms: Psidium guajava, Costalimaita ferruginea, temperature, precipitation, relative humidity. CORRELAÇÃO ENTRE DANOS OCASIONADOS PELO BESOURO AMARELO, ELEMENTOS CLIMATOLÓGICOS E PRODUÇÃO DE ACESSOS DE GOIABEIRA CULTIVADOS EM SISTEMA ORGÂNICORESUMO -O objetivo deste trabalho foi avaliar os danos ocasionados pelo besouro amarelo em 85 acessos de goiabeira e as correlações dos mesmos com os elementos climatológicos e a produção, em um pomar de goiaba conduzido em sistema orgânico. Foram analisadas 10 folhas por acesso contendo a injúria do ataque do inseto. Cada folha foi medida com medidor de área foliar e, após a obtenção da área total, a folha foi coberta com fita adesiva, e medida novamente. As médias foram comparadas pelo teste de Scott-Knott, a 5% de probabilidade. Os 15 acessos com maior média de danos tiveram os dados submetidos à correlação com a temperatura mínima e máxima, a precipitação e a umidade relativa. A produção foi obtida pelo número de frutos/planta. Os danos mostraram-se correlacionados negativamente com a média da umidade relativa das 7 h no período de 14 dias que antecedem as avaliações, afetando negativamente a produção de frutos. Os acessos Saito, L4P16, Monte Alto Comum 1 e L5P19 são promissores na agricultura orgânica, por apresentarem boa produção e menor dano ao ataque do inseto, quando comparados aos demais. Termos de indexação: Psidium guajava, Costalimaita ferruginea, temperatura, precipitação, umidade relativa.1 (Paper 260-15).

Growth and light environment of fruit trees in silvipastoral systems for rearing of dairy herds

“…The reductions in light interception of guava trees in the dry season of 2017 (Table 1), were attributed to the attack of the guava beetle (Costalimaita ferruginea) that feeds on the leaf lamina, leaving it with a partial or totally perforated (GALLI et al, 2017). The acerola fruit trees also showed leaf fall in the dry season of 2017, with a consequent reduction in light interception (Table 1), due to concurrent water stress (Figure 1).…”

“…This may be due to them having reached adulthood in the last dry season of the study period, thereby having a well-developed root system. This would allow the tree to have access to sufficient water and to avoid a reduction in leaves during periods of water stress (GALLI et al, 2017). Sehgal & Ranjit (2011) described the guava tree as a rustic fruit tree, adapted to the soil and climate conditions of the region and providing dense shade.…”