A determinação do teor de água de um lote de sementes é de fundamental importância para a avaliação de sua qualidade e armazenamento adequado. Portanto, o objetivo desse estudo foi comparar o método padrão da estufa com métodos alternativos para determinar o teor de água das sementes de milho (Zea mays), feijão (Phaeseolus vulgaris) e pinhão manso (Jatropha curcas). Foram utilizados os seguintes métodos: o método padrão da estufa a 105°C/24h; o método 101-105°C/17h; forno de micro-ondas por um, dois, três e quatro minutos na potência de 600W para milho e feijão e 1000W para pinhão manso, e o aparelho elétrico já calibrado para milho e feijão, utilizando-se a calibração de espécies oleaginosas (soja, girassol, canola, amendoim) para as sementes de pinhão manso. Os resultados foram submetidos à análise de variância e teste "F", as médias foram comparadas pelo teste de Student-Newman-Keuls (5%), e as estimativas dos parâmetros da regressão foram avaliadas pelo teste "T" (5%). Para sementes de milho e feijão, em forno micro-ondas o tempo para obter o teor de umidade semelhante ao método padrão da estufa foi de 2 minutos e 35 segundos e 2 minutos e 42 segundos, respectivamente, à potência de 600 W. Para estas duas espécies pode ser utilizado ainda o aparelho medidor de umidade. Para sementes de pinhão-manso em forno micro-ondas à potência é de 1000 W e o tempo de 2 minutos e 11 segundos para obter o teor de umidade semelhante ao método padrão da estufa; já no medidor de umidade pode ser realizado com calibração para canola. Assim, a determinação do teor de água de sementes de milho, feijão e pinhão-manso em forno de micro-ondas e medidor de umidade podem se tornar métodos alternativos ao da estufa.

The alternative use of plant essential oils as pesticide, repellent and/or antifeedant has been emphasized as an important tool in integrated pest management (IPM), promoted by the growing interest in methods that fulfil requirements of efficiency, safety, selectivity, technically feasible and environmentally safe. The objective of this work was to determine the pesticide potential of essential oils of rosemary pepper (Lippia origanoides Kunth; Verbenaceae), citronella (Cymbopogon winterianus Jowitt; Poaceae) and lemongrass (Cymbopogon citratus [DC.] Stapf; Poaceae) to control fall armyworm (Spodoptera frugiperda [J.E. Smith]; Lepidoptera: Noctuidae). Ovicidal, larvicidal and pupicidal activity was evaluated with five dosages (0.1%, 0.5%, 1.0%, 2.5% and 5.0% v/v) and a negative control (neutral detergent at 5.0% v/v). Unhatched eggs, mortality of caterpillars and non-emerged adults were recorded using ovicidal and pupicidal percentage, and median lethal doses (LD50) to caterpillars. The essential oils showed insecticidal activity on the egg, caterpillar 3 rd instars and pupae stages, highlighting the rapid action and high mortality rates caused by the L. origanoides essential oil, which registered, at lowest dosage, average 97.8% ovicidal activity and 81.3% pupicidal activity; in addition to LD50 on 3 rd instar caterpillars, 0.001% by exposure and 0.033% by topical application. Essential oils of C. citratus and C. winterianus required longer periods to act and caused significant mortality on the three stages, registering LD50 0.008% and 0.159% for exposure, and 1.151% and 1.348% for topical application, respectively. Citronella oil caused behavioral changes in caterpillars, which reflected flight and aggressiveness. Therefore, these three essential oils can be an alternative for management of fall armyworm, with the potential to hinder and reduce its biotic potential.

The possibility of cultivation without the use of chemical insecticides or reduction thereof, associated with the requirements of consumers has motivated growers to return to the practice of bagging fruit, but it is possible that this technique causes changes in the visual and organoleptic characteristics of fruits. The objective of this study was to evaluate possible changes in postharvest characteristics in 'Valerin' tomato fruits produced inside nonwoven bags (TNT) and validate the best period for bagging. The fruits came from commercial cultivation of tomato plants, located in "Ubajara", "Ceará" State, Brazil. The experiment design used 2 × 4 factorial randomized blocks with five repetitions. The factors considered two types of insecticide use: 1-Plants treated with insecticides and 2-Plants not treated with insecticides, and four ways to bag the bunches with nonwoven fabric (TNT): T1-Bagging flower, T2-Bagging the bunches with fruits with a 1.5 cm diameter, T3-Bagging the bunches with fruits with a 3.0 cm diameter, and T4-Bunches not bagged (control). Variations in color parameters (brightness and hue angle) and firmness did not compromise the fruit quality when bagging was conducted in the flower stage (T1) or when the fruits had a 1.5 cm diameter (T2). The other parameters (titratable acidity, total soluble solids, total carotenoids, lycopene and ß-carotene) showed no change when compared to the control. Bagging the tomato bunches in the flower stage or when the fruits had a 1.5 cm diameter did not change the postharvest quality.Additional key words: Solanum lycopersicum, pest control, fruit quality.

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