Banca de DEFESA: RICARDO FALESI PALHA DE MORAES BITTENCOURT

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : RICARDO FALESI PALHA DE MORAES BITTENCOURT
DATE: 30/06/2022
TIME: 08:00
LOCAL: sala do google meet
TITLE:

"LETTUCE GROWING IN HIGH TEMPERATURE CONDITION: SELECTION OF LETTUCE CULTIVARS AND NUTRITION WITH MAGNESIUM"

KEY WORDS:

Magnesium fertilization; Bolting; Production and quality; Hydroponics

PAGES: 68
BIG AREA: Ciências Agrárias
AREA: Agronomia
SUMMARY:

The lettuce (Lactuca sativa) is the most commercialized leafy vegetable worldwide, having its consumption predominantly in the form "in natura", being the crespa type the most commercialized in Brazil. However, this crop comes from temperate climates, presenting some limitations in production and development, mainly due to the precocious bolting, which is recurrent in regions that present temperatures above 28 °C. In this sense, the objective of this work was to evaluate the performance of crisp lettuce cultivars in a hydroponic system in a hot climate region, as well as the effects of Mg concentrations in the nutritive solution. To accomplish this, two experimental trials were conducted in an entirely randomized design. The first trial evaluated the biochemical, productive, physiological and postharvest quality performance of 9 cultivars of crisp lettuce, as well as their suitability for cultivation in warm climatic regions. The second trial evaluated the effect of concentrations of 0.01, 0.5, 1, 2 and 4 mmol Mg L^-1 on antioxidant enzyme activity, electrolyte leakage from leaves, physiological performance, growth, yield and postharvest quality of two lettuce cultivars with different suitability for warm climatic regions. Based on the results of the first trial, it was possible to observe a greater productive aptitude of the cultivars Olinda and Cristina, which did not express bolting, and also presented a better productive performance in relation to the other materials evaluated. We highlight the differences between the two cultivars, which serve two distinct markets in alfaculture. We also observed that among the materials tested, the variety Monica is the most susceptible to fruit set in regions with hot climates, due to its greater precocity and degree of expression of bolting. As for the effects of Mg concentrations, we observed that the contemplation of Mg nutritional status was not sufficient to mitigate the expression of early bolting. However, Mg promoted improvements in antioxidant responsiveness, photosynthetic performance, growth and yield of lettuce cultivars, with estimated critical concentrations of 2.44 mmol Mg L^-1 and 2.92 mmol Mg L^-1, respectively for Olinda and Monica cultivars.

BANKING MEMBERS:
Externa ao Programa - 388335 - ANA REGINA DA ROCHA ARAUJO
Externo à Instituição - HOZANO DE SOUZA LEMOS NETO - UFPI
Presidente - 1228204 - MARIO LOPES DA SILVA JUNIOR
Externo ao Programa - 817.005.552-00 - RODOLFO INACIO NUNES SANTOS