Abstract The main objective of this study is to propose different probabilistic models for adjusting the trend component, since it significantly influences the quality of the spatio-temporal interpolation of rainfalls. We used the monthly total precipitation data of the São Francisco River Basin (SFRB) for the period of 31 years, 1989–2019. The SFRB occupies 8% of the whole Brazilian territory, mostly located in the Northeast Brazilian region. For the trend component, we propose the fitted GAMLSS models by comparing different probability distribution families, which in most cases include the characteristics of these data. The results indicate the existence of a spatio-temporal pattern of the residues obtained from the adjustment of the trend with zero adjusted Gamma distribution for the accumulated monthly precipitation. The adjustment revealed a spatial dependence of up to 873 km between the pluviometric stations and temporal autocorrelation of approximately 1.6 months. The methodology used in this study enabled us to create rainfall maps, interpolating unobserved locations in differences years. The projection of these maps to the SFRB is considered extremely important for planning and implementing activities related to water resources across the river basin.

Resumo Dados de experimentos de campo conduzidos em parreirais de uva de mesa da variedade Festival, em Petrolina-PE, no período de outubro/2009 a novembro/2010, foram usados para avaliar a influência da cobertura plástica sobre o microclima, produtividade e impacto econômico de parreirais. Foram estudados três tratamentos: sem cobertura (SC); com cobertura plástica posicionada a 50 cm acima do dossel (CP50); e com cobertura plástica posicionada a 100 cm acima do dossel (CP100). Os resultados indicaram que a maior oferta de fluxos radiativos na altura das bagas no tratamento CP100 contribuiu para uma maior produtividade, enquanto que o tratamento CP50 teve a menor oferta de fluxos radiativos na altura das bagas e uma produtividade bem menor. A produtividade obtida no tratamento CP100 superou em 11 t ha-1 àquela do tratamento SC e em 12,3 t ha-1 a do tratamento CP50. O tratamento CP100, também foi o que apresentou as menores quantidades de defeitos graves e leves, o que contribuiu para uma maior receita total. Em contra partida, o tratamento CP50 teve uma produtividade acentuadamente menor, o que representou prejuízos econômicos consideráveis.

Abstract Data from field experiments conducted in vineyards table grape variety of Festival in Petrolina-PE, from October/2009 to November/2010, were used to evaluate the influence of the plastic cover on productivity and economic profitability of the viticulture in the São Francisco River Valley. Three treatments were studied: uncovered canopy (UC), plastic cover placed at 50 cm above the canopy (PC50), and a plastic cover placed at 100 cm above the canopy (PC100). The results indicated that the increased supply of radiative fluxes at the height of the berries in the treatment PC100 contributed to higher productivity, while treatment PC50 had the lowest offer of irradiative fluxes at the height of berries and much lower productivity. The yield obtained in the treatment PC100 exceeded 11 t ha-1 and 12.3 t ha-1 to those of treatments at UC and PC50, respectively. Treatment PC100 also had the lowest amounts of defects of berries, which contributed to higher total revenue. By contrast, treatment PC50 had markedly lower productivity, which represented considerable economic losses.