Efeito alelopático de extrato de centeio na germinação de sementes e crescimento de plântulas de cenoura e beterra

Abstract

Allelopathy may inhibit or stimulate plant development. The use of plants to cover the soil can result in allopathic effects on the germination and early seedlings development of through the release of secondary (allochemical) metabolites. Thus, the present work aims to verify if the aqueous extract of rye exerts allelopathic action on germination and seedlings growth of beet and carrot. The experimental design was completely randomized, in a 2 x 4 factorial scheme (cultivars x concentrations), with five replications, for each species separately. Beet seeds, Early Wonder and Vermelha Comprida, and carrot seeds of Brasília Irecê and Kuronan cultivars were used. The extracts were prepared using whole rye plants, in concentrations of 0 (control), 25, 50 and 100%. The seeds were conditioned in gerbox plastic boxes, with germitest paper moistened with the extracts. The analyzed variables were: percentage of germination, of non-germinated seeds and abnormal seedlings, speed germination index, length of shoot and roots of seedlings, and seedling dry mass (shoot and roots). The data were submitted to analysis of variance and when this was significant, the regression analysis was performed. The increase in the concentration of aqueous extract of rye causes linear reduction of the germination of carrot seeds. Carrot seedlings growth is adversely affected by aqueous extract of rye. The aqueous extract of rye reduces the germination of beet seeds. Beet seedlings growth is affected by the rye extract, with variable effect as a function of the cultivar.