Leandro do Prado Ribeiro

Ação de extratos de plantas na oviposição e na mortalidade da traça-das-crucíferas

The diamondback moth, Plutella xylostella (L.) (Lepidoptera, Yponomeutidae), is one of the most important insect pest species of the Brassicaceae family plants in Brazil and in the world. The use of insecticidal plants extracts in the control of this insect is a promising alternative. Therefore, this research goal is to evaluate, in laboratory, the plants extracts effect on the oviposition and mortality of P. xylostella. In order to analyze the effect on the oviposition, kale leaf pieces were treated, in cage, as following: aqueous extracts (10% p/v) of leaf of chinaberry (Melia azedarach), of branch of chinaberry, of tobacco powder (Nicotiana tabacum), besides DalNeem (commercial product, based on Azadirachta indica), at 10% v/v. Inside the cage, 50 adults of P. xylostella were put and, 48h later, the egg number per leaf was counted, in seven repetitions. A second assay was consisted of the exposition of three larvae to the same cited extracts, in glass tube with a kale leaf piece previously treated. Three glass tubes were used per treatment, with four repetitions. The number of death larvae was evaluated daily. The aqueous extracts of chinaberry leaf, chinaberry branch and tobacco powder, besides DalNeem, reduce the oviposition of P. xylostella and the use of tobacco powder extract, DalNeem and chinaberry branch extract result in efficient control of P. xylostella larvae after the second, fifth and sixth days after application, respectively.

Qualidade de sementes de milho armazenadas em diferentes embalagens

The storage is a decisive part of seed production of high quality. The objective of this study was to evaluate the physical, physiological and sanitary quality of three maize varieties seeds, stored for six months in plastic packaging and cotton bags. Germination, quantification of insect damage and seed health were evaluated. In the plastic packaging storage, were observed reduction in the germination, but the presence of insect pests was lower. The storage in cotton bag reduced the seeds quality, due to the presence of insect pests and the high incidence of Fusarium, Penicillium and Aspergillus. The storage in plastic package provided the maintenance of seeds quality, with a lower incidence of insects and fungi when compared to the cotton bags. The varieties showed different answers in relation to the packages used.