Produção e tolerância ao florescimento precoce em alface: cultivares e épocas de cultivo

Abstract

Lettuce is the most consumed small vegetable crop in the world. Due to its high consumption and perishability the plant needs to be cultivated in all regions of the country and at all times of the year to fill the market. With origin in temperate regions, lettuce plants present restrictions in the development in regions and/or times with high temperatures, inducing its early flowering and signaling the end of the vegetative stage. The objective of this work was to evaluate the tolerance to precocious flowering crispy lettuce cultivars, at different growing seasons, in Chapecó-SC region, produced in the field and protected environment. The work was developed at the Federal University of Southern Frontier, Chapecó campus and at Vanderlei Savaris farm’s, in Caravaggio line, Chapecó-SC. The experimental design was a randomized complete block design in a 6 x 2 factorial scheme, with six cultivars (Milena, Vanda, Vera, Valentina and Pira Verde Grand Rapids) in two growing seasons in the summer (February and March 2017). separately for each crop environment (protected and field). The experimental plot consisted of beds with three lines each, with ten plants per line, considering the useful portion the seven central plants. At the time of flowering the date was recorded, to count the number of days from seedling transplant to initial flowering. After harvest, plants were taken to the UFFS laboratory, and evaluated for the following characteristics: stem length, plant diameter, total and commercial fresh mass of the plant, number of leaves, yield of commercial and total fresh mass. The data were submitted to analysis of variance and the means were compared by Tukey test at 5% probability by Assistat®. Cultivars Pira Verde, Milena, Valentina and Vanda are tolerant to early flowering, under the conditions evaluated in this research. In the protected environment the best growing season, in the summer, of crispy lettuce, was the first evaluated season, with seedlings transplant in February and harvest in April. In the open field environment the best growing season was the second, with seedling transplantation in the month of March and harvest in May.