Development of cassava plants jurará creme submitted to chemical fertilization in different periods

Abstract

The aim of this study was to evaluate the responses of the Jurará Creme cassava variety submitted to chemical fertilization with phosphorus and nitrogen in different days of application after sprouting (DAS). The experiment was carried out at the Universidade Federal Rural da Amazônia, Belém – PA. The experimental design was in randomized blocks with five treatments (T1 – phosphate fertilization on foundation + 30 DAS nitrogen fertilization; T2 – 30 DAS phosphate fertilization + 60 DAS nitrogen fertilization; T3 – 30 DAS phosphate fertilization + 90 DAS nitrogen fertilization; T4 – phosphate fertilization 30 DAS + nitrogen fertilization 120 DAS; T5 – phosphate fertilization 30 DAS + nitrogen fertilization 150 DAS) and five repetitions. The variables analyzed were: stem diameter; plant height; number of total and commercial roots; number of sheets; fresh mass (stump, total roots without strain, commercial roots, stem and leaves); total and commercial root length; diameter of commercial roots; dry mass (strain, commercial roots, stem and leaves); and harvest index. Data were submitted to Analysis of Variance and Tukey test at 5%. It was found that treatments T4 and T5 positively affected the number of leaves, stem diameter, number of total and commercial roots, length of total and commercial roots, diameter of commercial roots, fresh mass of total and commercial roots, fresh mass of the stem, leaf fresh mass, stump dry mass, stem dry mass and harvest index. Thus, it was concluded that the variety of cassava Jurará Creme was more responsive when phosphorus fertilization was performed at 30 days after sprouting and nitrogen fertilization performed at 120 and 150 days after sprouting.