Banca de DEFESA: ANA BEATRIZ CARNEIRO LEITE

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : ANA BEATRIZ CARNEIRO LEITE
DATE: 27/02/2025
TIME: 13:00
LOCAL: Vídeo conferência
TITLE:

Phytotechnical performance of crisp lettuce as a function of the application of irrigation depths and doses of fermented bran compost under organic management

KEY WORDS:

Irrigation management, soil water balance, capacitive sensor, organic fertilization, Bokashi, Lactuca sativa.

PAGES: 65
BIG AREA: Ciências Agrárias
AREA: Agronomia
SUBÁREA: Fitotecnia
SUMMARY:

Lettuce (Lactuca sativa) has high nutritional requirements and is highly sensitive to soil moisture, and the occurrence of water deficit and high temperatures can lead to significant loss of productivity. Two experiments were conducted to evaluate the phytotechnical performance of crisp lettuce cv. Vera subjected to different irrigation depths and doses of fermented compost under organic management. In addition, it was intended to determine the phenological stages of crop development using the accumulated degree-days methodology. The first experiment was conducted using a randomized block design in a split-plot scheme, with four irrigation levels in the plots (50, 66.7, 83.3 and 100% of the crop water requirement (ETc)) and four doses of fermented organic compost in the subplots (0, 250, 500 and 750 g m^-2), with five replicates and a total of 20 plots. The organic compost was produced from Gliricidia sepium bran and brewery waste at the “Fazendinha Agroecológica Km 47”, and the crop water requirement was determined from the soil water balance using capacitive sensors. The coverage fraction and the determination of the phenological stage were performed from photographic monitoring and the degree-days (DDD) and accumulated degree-days (ADD) in each stage were also determined. Harvesting was performed at 35 DAT, and the following phytotechnical parameters were evaluated: chlorophyll content (a, b and total), fresh shoot mass (MFPA), number of leaves (NF), leaf area (AF) and dry shoot mass (MSPA). Statistical analysis of the data indicated that there was no interaction between irrigation depth and dose of fermented compost, and there was no statistically significant difference for the applied depths in all variables. There was a dose effect for all variables, except for chlorophyll content. Therefore, regression analysis was performed in which the second-degree polynomial model presented the best fit for all variables analyzed. The results indicate that the dose of 0 kg N ha^-1 presented lower means in all variables, and that the optimal dose would be 227 kg N ha^-1. Based on the best dose of organic compound, a second experiment was carried out to evaluate crop development under different water supplies, when the characteristics of the aerial part (NF, AF, MFPA and MSPA) and root (dry mass and depth) were measured at six different times (7, 14, 21, 28, 35 and 42 DAT). In this experiment, a randomized block design was used, with treatments consisting of four irrigation depths equivalent to 100, 60, 40 and 20% of ETc and the optimal dose of bran compost, with five replicates. Supplying 100% of the crop's water requirement provided the best plant development, evidenced by the superior results in all variables. The results of DDD and ADD indicate that nitrogen fertilization directly influenced the lettuce growth rate, especially in the initial phases of the cycle, allowing its progression to more advanced stages.

COMMITTEE MEMBERS:
Presidente - 1224578 - DANIEL FONSECA DE CARVALHO
Interno - 2181674 - LEONARDO OLIVEIRA MEDICI
Externo à Instituição - CARLOS RODRIGUES PEREIRA - UFF