EVALUATION OF PEST INCIDENCE IN YELLOW IPÊ (TABEBUIA SERRATIFOLIA) SEEDLINGS UNDER THE EFFECT OF BASE SATURATION IN A DYSTROPHIC YELLOW LATOSOL MEDIUM TEXTURE

Abstract

The yellow Ipê (Tabebuia serratifolia) is a forest species found in several regions of Brazil, in addition to having economic importance for the market for the production of seedlings, hardwood and urban landscaping. This research aims to evaluate the incidence of pests in seedlings of yellow Ipê (Tabeluia serratifolia), in order to identify the main pests that occur in the crop and their correlation with different levels of base saturation. The work was carried out in a greenhouse in a completely randomized experimental design (DIC), and the respective amounts of dolomitic limestone with PRNT of 98% were applied in the 5 treatments (V0% - initial soil saturation (without lime application); V20% (0.5 g), V40% (4.0 g), V60% (7.5 g) and V80% (11.0 g) and 5 replicates. After 30 years of soil incubation with the application of limestone, seedlings of yellow Ipê were transplanted and the nutrient solution (with macro and micronutrients) was applied and during the development of the plant, five inspections were carried out, analyzing five leaves at random per treatment, with the function of verifying the study of variables such as: attacked leaf area (use of the calculation of base x height in the lesions),  average attack, type of pest (identification, through Embrapa's identification guide) and leaf area damage levels (low (0 to 15%), medium (15 to 30%) and high (greater than 30%)). Regression analyses were performed on the variables using Microsoft Office Excel 2013 and hierarchical cluster and Euclidean distance model analyses using the IBM SPSS Statistics 25.0 software. It was observed that the area of the plants that suffered the greatest attack by pests was the foliar, and no attacks on the stem of the plants were observed. The treatment that suffered the least from pest attack was V20%= 0.5g of limestone, where there was almost no incidence of pests analyzing the five inspections carried out during the experiment. Showing that this level of soil correction (0.5g of limestone) raised the base saturation index to 42.99%, increasing the concentration of nutrients in the seedlings to adequate levels according to literature recommendations, favoring resistance to pest attack. On the other hand, the treatment where the most attack occurred was V40% = 4.0g of limestone, where the levels of damage in the leaf area were higher, demonstrating that base saturation levels equal to or greater than 44.28% do not favor the crop in terms of resistance to pest attack. It was concluded that base saturation levels lower than 42.99% reduce the incidence of pests in the Ipê-amarelo crop, and values above this can favor pest attack. The pests that affect this crop in the Northeast region of Pará, according to the study, were the grasshopper (Orthoptera, Acrididae, Leptysminae) and the caterpillar of the species Anartia jatrophae. High rates of attack on the leaf area of the seedlings cause a drop in photosynthetic power and thus decrease energy gain, harming their development.