Crescimento de mudas de cacaueiro (Theobroma cacao L.) sob doses crescentes de micronutrientes em solo

Abstract

Adequate nutrition is essential for the production of high-quality seedlings, ensuring the vigor and health of plants from the initial phase. Good nutrition is fundamental for root and leaf development, as well as for resistance to diseases and pests. Providing the necessary nutrients from the beginning maximizes the productive potential of the seedlings, resulting in more robust and productive plants in the field. The objective of the study was to evaluate the development of cocoa seedlings produced with different doses of micronutrients in the city of Juruti-PA. The seeds used come from a commercial orchard located in the municipality of Uruará-PA; they were washed, dried, and planted in bags containing sawdust and soil in a 1:1 ratio. Once germinated after five days, they were transplanted into plastic containers (bags) 15x33 cm, containing soil from the experimental farm of the Juruti Campus, UFOPA. A Completely Randomized Design was used with five treatments: 0.0 (control); 25; 50; 75; and 100 mg.dm3 of micronutrient complex. Each treatment comprised eight repetitions, totaling 40 experimental units. The evaluations consisted of measurements of leaf area (LA), number of leaves (NL), stem diameter (SD), and height (H). At the end of the experiment, the seedlings were subjected to destructive analysis, where the dry and fresh mass of the roots and shoots (g) were evaluated. For dry mass, the samples were placed in an oven for 72 hours at 70°C. The use of increasing doses of micronutrients in cocoa seedling treatments showed significant results for shoot and total dry mass, while the other variables did not show significant differences.