Controle e repelência de sitophilus zeamais com cinza de diferentes órgãos e espécies vegetais

Abstract

Sitophilus zeamais , the corn weevil, stands out among the main insect pests of stored grains and seeds. With a view to valuing the production of food with more sustainable production bases, the use of products with less impact on both the environment and the health of consumers is sought. Thus, the present work aimed to evaluate the efficiency of ash from different organs and plant species in the repellency and control of Sitophilus zeamais and its influence on the physiological quality of maize seeds during storage. The experiment was conducted at the Federal University of Fronteira Sul, campus Laranjeiras do Sul, PR. The corn seeds were submitted to the following treatments: rice husk ash; eucalyptus leaf ash; pine wood ash; ash from different woods; eucalyptus wood ash; diatomaceous earth and control, consisting of untreated seeds. The dosage used in the treatments was 10 kg t-1 of seeds. Three days after seed treatment, 40 non-sexed adult insects, aged between three and five days, were infested. The treatments were stored for 120 days at a temperature of 25 °C. At each storage period (0, 30, 60, 90 and 120 days) a sample of seeds was taken from each repetition to carry out the following tests: moisture, germination, repellency, seed infestation, insect mortality and weight of a thousand seeds. Based on the results obtained, it was possible to conclude that: among all the treatments used, diatomaceous earth, pine wood ash and eucalyptus leaf ash were the most effective in controlling Sitophilus zeamais . The mortality of S. zeamais was significantly influenced by the time of exposure to treatments, with a higher mortality rate at longer exposure times. The treatment with ash from different woods was repellent to Sitophilus zeamais throughout the seed storage period. The treatments with eucalyptus wood ash, diatom and rice ash were repellent from the first month of storage and pine wood ash was attractive. The treatment with pine wood ash, in addition to preserving the germination power of corn seeds until the end of storage, was highly persistent and efficient in the control of Sitophilus zeamais , constituting a good option for seed treatment. None of the treatments used affected the physiological quality of the seeds.