Zinc is an element found in low amounts in the soil, which may limit the development of agricultural crops. In addition, the absorption of this nutrient by plants is directly influenced by several factors such as: high pH, ​​amount of organic matter, high humidity associated with low temperatures and soil microbiota. Zinc is important for enzymatic activity, being a constituent part of the enzymes alcohol dehydrogenase, carbonic anhydrase, superoxide dismutase enzyme and polymer RNA, in addition to participating in the synthesis of precursor tryptophan in the metabolism of indoleacetic acid, which is a plant hormone directly related to the development of plants. In plants, the symptoms of zinc deficiency appear with the shortening of the internodes, reduction of the leaf area, reduction of its size, appearance of rosettes, chlorosis and necrosis. Thus, the objective of this review is to present the main aspects of the zinc nutrient in the soil and the functions performed in plants.

Raoiella indica Hirst, 1924 (Prostigmata: Tenuipalpidae), is one of the main pest mites of palm and banana trees, causing significant damage in producing regions. Thus, the objective of this work was to evaluate the acaricidal effect of soursop peel extract (Annona muricata L.) on R. indica adults. The experiment was conducted in a completely randomized design using soursop peel extract, with 7 replications and 12 individuals of R. indica per replication. The experimental units consisted of discs of coconut palm leaves (4 cm in diameter), with cotton moistened at the bottom of the Petri dish (10.0 x 1.2 cm) and around the disc to maintain turgor and prevent mites from escaping. The application was carried out using an airbrush, connected to a calibrated compressor with a constant pressure of 1.3 psi and 1 mL of solution per plate. The acaricidal effect was evaluated 24, 48, and 72 hours after spraying. Mortality data were corrected and subsequently submitted to probit analysis (p≤0.05) using the statistical program R, with the LC50 and LC90 of the extract being calculated. The soursop peel extract at the maximum concentration used (15%) showed mortality of 80% of individuals of R. indica. The LC50 was 1.934%. It was concluded that extracts from soursop peel have acaricidal potential on R. indica in the laboratory.

The aim of this work was to study the effect of the interaction between castor bean oil (Ricinus communis) and jatropha oil (Jatropha curcas) on the aphid, Myzus persicae. The experiment was realized at the Institute Federal of Espírito Santo in Brazil. Tests were conducted in a completely randomized design, with 11 treatments and 10 repetitions, arranged in a factorial arrangement of 11 (interactions between oils) x 2 (application forms). The concentration used in this test was 3 %. Treatment interaction ratios were 0-100; 10-90; 20-80; 30 -70; 40-60; 50-50; 60-40; 70-30; 80-20; 90-10; 100-0 % jatropha and castor bean oil, respectively. Tests of direct and indirect application were performed. The evaluations were performed 24, 48, and 72 hours after the applications. For both forms of application, there were significant mortalities. Mortalities greater than 70 % were observed when the interaction contained more significant amounts of jatropha than castor bean. However, a negative interaction was observed between concentrations with similar proportions. In conclusion, for both application forms, the interaction between jatropha and castor bean oils effectively reduce the population of M. persicae.

Raoiella indica Hirst, 1924 (Prostigmata: Tenuipalpidae), is one of the leading pest mites in palm and banana trees, however, there are few control methods available for this pest species. Therefore, this work aimed to evaluate the acaricidal effect of soursop seed extract (Annona muricata L.) on R. indica adults. The experiment was conducted in a completely randomized design using soursop seed extract with 7 replicates and 12 individuals of R. indica per replicate. The experimental units consisted of discs of coconut palm leaves (4 cm in diameter), with cotton moistened at the bottom of the Petri dish (10.0 × 1.2 cm) and around the disc to maintain turgor and prevent mites from escaping. The application was performed using an airbrush, connected to a calibrated compressor with a constant pressure of 1.3 psi and 1 mL of solution per repeat plate. The acaricidal effect was evaluated 24, 48, and 72 hours after spraying. Mortality data were corrected and submitted to Probit analysis (p ≤ 0.05) using the statistical program R, with the LC 50 and LC 90 calculated for the extract. At the maximum concentration (15%), the soursop seed extract showed mortality of 70% of individuals of R. indica, and the LC 50 was 6.58%. It was concluded that the soursop seed extract showed acaricidal potential on R. indica in the laboratory.