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-The objective of this work was to assess the effects of Aspidosperma pyrifolium ethanol extracts on cabbage moth (Plutella xylostella) larvae. The ethanol extracts of the stem bark, fruits and roots of A. pyrifolium were obtained by classical phytochemical methods, and the resulting subfractions were tested on P. xylostella, using 4 and 5 mg L -1 . The crude ethanol extract of the stem bark was more lethal. The alkaloid-rich aqueous subfraction derived from the stem bark extract caused 100% larval mortality at 4 mg L -1 . Insecticidal activity was associated with the presence of the monoterpenoid indole alkaloids aspidofractinine, 15-demethoxypyrifoline, and N-formylaspidofractinine. These alkaloids presented excellent insecticidal properties against P. xylostella.Index terms: Brassica oleracea var. acephala, alkaloids, cabbage moth, insecticidal activity, organic extracts, pereiro-do-sertão. Mortalidade de larvas de Plutella xylostella tratadas com extratos etanólicos de Aspidosperma pyrifoliumResumo -O objetivo deste trabalho foi avaliar os efeitos dos extratos etanólicos de Aspidosperma pyrifolium sobre lagartas da traça-das-crucíferas (Plutella xylostella). Os extratos etanólicos da casca do caule, do fruto e da raiz de A. pyrifolium foram obtidos pelos métodos fitoquímicos clássicos, e as subfrações resultantes foram testadas contra P. xylostella, nas dosagens 4 e 5 mg L -1 . O extrato bruto etanólico da casca do caule foi mais letal. A subfração aquosa rica em alcalóides, derivada do extrato da casca do caule, causou 100% de mortalidade larval a 4 mg L -1 . A atividade inseticida foi associada à presença dos alcalóides monoterpenóides indólicos aspidofractinina, 15-demetoxipirifolina e N-formilaspidofractinin. Estes alcalóides apresentaram excelente propriedade inseticida contra P. xylostella.Termos para indexação: Brassica oleracea var. acephala, alcalóides, traça-das-crucíferas, atividade inseticida, extratos orgânicos, pereiro-do-sertão.

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It was evaluated how straw management modifies the development, growth, nutrient cycling and crop water productivity of sugarcane in the semiarid region of Brazil. The experiment was carried out using two plots with 5 ha each, being one without straw on the soil surface and one with 26 Mg•ha −1 covering the soil. Sugarcane growth and development and straw decomposition coefficient were evaluated, whereas the industrial yield, juice quality, dry matter partitioning, and crop water productivity were determined at harvesting. The straw decomposition coefficient was 0.0049 Mg•ha −1 •day −1 , and the remaining dry mass was equal to 24%. The straw affected the sugarcane growth and development until the first 100 days. The individual internode volume can be adopted as an indicator of the effect of straw on sugarcane growth because the internode volumes up to the sixth position in the with-straw treatment crop were lower than in the no-straw treatment, which was not observed in other variables of the stalks. Keeping straw on the soil surface reduced the crop lodging. Yield and juice quality were not affected, but crop water productivity was increased by keeping sugarcane straw in the field.