The coconut mite, Aceria guerreronis Keifer (Acari: Eriophyidae), is a severe and ubiquitous pest of coconut plantations worldwide. Vegetable oils contain fatty acids that are active against a variety of agricultural pests; however, little is known about their efficiency in controlling A. guerreronis as well as their adverse effects on its natural enemies. Here, we assessed the chemical profile of palm oil as well as its toxicity and repellence to both A. guerreronis and Typhlodromus ornatus Denmark and Muma (Acari: Phytoseiidae), a natural enemy of the pest. Oleic, palmitic, and linoleic acids accounted for over 85% of palm oil fatty acid composition. Also, palm oil was approximately 4-fold more toxic to the coconut mite than to its predator. Furthermore, the lethal concentration percentage (LC) 50 and LC 99 of palm oil indicated greater activity against the coconut mite than to its predator. Therefore, by exhibiting higher toxicity and repellence to the coconut mite, with substantial selectivity to the predator T. ornatus, palm oil is a promising tool to be integrated in the control of A. guerreronis in coconut plantations.
Typhlodromus (Anthoseius) ornatus Denmark & Muma (Acari: Phytoseiidae) is one of the predatory mites associated with the coconut mite Aceria guerreronis (Acari: Eriophyidae), considered a severe pest of coconut plantations worldwide. In addition to predatory mites, vegetable oils such as degummed soybean and babassu oils have shown high efficiency in controlling A. guerreronis. Here, we evaluated the effects of degummed soybean and babassu oils on the functional response and oviposition of T. (A.) ornatus preying on A. guerreronis. Exposure to the tested oils did not alter either the functional response or the attack rate of T. (A.) ornatus. The variation in prey consumption with the exposure to vegetable oils did not differ from the control, although degummed soybean oil led to higher consumption compared to babassu oil. In addition, prey handling time and peak consumption were negatively affected by the exposure to babassu oil. The number of eggs laid by the female of T. (A.) ornatus at intermediate prey density decreased under exposure to degummed soybean oil. Overall, our results indicate that the tested oils are generally compatible with T. (A.) ornatus as they do not alter predatory responses but oviposition rate is affected by degummed soybean oil.
Aspects related to tomato (Solanum lycopersicum L.) mineral nutrition are important for the production of quality fruits. The cherry tomato (Solanum lycopersicum var. cerasiforme) is an alternative for most producers due to its high market value, greater productivity and good acceptance by consumers. The objective with this study was to evaluate the nutritional status of cherry tomatoes cultivated in nutrient solution under omission of macronutrients. The experiment was conducted in a completely randomized design, with seven treatments: complete nutrient solution and omissions of N, P, K, Ca, Mg and S, with five replicates. Visible symptoms of nutritional deficiency were observed in the following order of omission: at 5, 12 and 20 days after transplantation in plants under omission of N, P and K, respectively. Conversely, there were no visible symptoms of deficiency under omissions of Ca, Mg and S. The sequence of growth limitation, determined based on the shoot dry mass of cherry tomato plants, was: N>P>S>Mg>Ca>K. The omission of a nutrient, besides reducing its content in the leaf tissue, causes imbalance between the other nutrients, influencing the parameters of growth and production, leading to morphological manifestations in cherry tomato.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.