Diferentes temperaturas na germinação de duas variedades de manjericão

Abstract

The basil is one of aromatic and culinary species that are grown and marketed in almost all brazilian territory. To have a profitable production is required to acquire a good quality seed, so that they can give normal plants and express the maximum possible production. One of the factors that affect seed germination is the temperature, which is decisive for the germination and seedling establishment in the environment. This study aimed to evaluate the influence of temperature on germination of two basil cultivars. Were used seed of the varieties “Thin Leaf” and “Purple”, with sowing in Germitest paper, moistened with distilled water in petri plates at the Laboratory of Research in Floriculture, located in the Department of Plant Science of the Federal University of Ceará. The seeds were accomodated in a germination chamber B.O.D. type in the presence of light and at constant temperatures of 20ºC, 25ºC, 30ºC, 35ºC and 40ºC. For all treatments were used five replications of 20 seeds for the two evaluated varieties. The seeds were submitted to four counts with 7, 8, 9 and 10 days after sowing. The variables used were germination percentages, normal seedlings, dead seeds, germination speed index (GSI) and the average germination time (GMT). The treatments were arranged in a completely randomized design (CRD), arranged in a 2x5 factorial scheme (V X T). Each treatment contained five repetitions, where each repetition consisted of 20 seeds, totaling 100 seeds per treatment. The data were submitted to basic descriptive analysis and normality test and was later carried out the analysis of variance (ANOVA). Comparisons between varieties were performed by Tukey test at 5 % probability. In the evaluation of temperature effects and the interaction between the factors we used regression analysis to the level of 0.01 (**) and 0.05 (*) probability by F test and the highest coefficient of determination (R2). The “Thin Leaf” variety maintained its constant germination among the analyzed temperatures, but there was a higher number of dead seedlings at 40°C. The germination percentage is maximum for “Purple” variety at temperatures of 20 to 30°C.