Pre-treatment by light in stored seeds of caupi beans benefits germination and uniformity of growth

Abstract

Adequate storage of caupi bean seeds is an essential step for the conservation of seeds with high physiological quality. Alternative ways must be found that, associated with storage conditions, help in the preservation for the seeds´ best performance. Current study tested pre-treatments with light combined with hydroconditioning in stored seeds of caupi beans (Vigna unguiculata (L.) Walp.) and assessed their influence on the seeds´ physiological quality. Methodology comprised experiment in which caupi beans underwent hydroconditioning and pretreatments with different light regimes (white, dark, red, dark-red, green and blue) for a period of 5 h, followed by drying for 48h. Variables analyzed were emergence, emergence speed index, length of shoot and root, shoot and root dry mass. Experimental design was totally randomized in a 5 x 6 factorial scheme: storage periods: 40, 80, 120, 160 and 200 days, associated with light regimes such as white, dark, red, extreme red, green and blue). Results indicate that extreme blue, red and dark-red light regimes affect growth and development of caupi bean seedlings throughout storage. Pre-treatments with extreme blue, red and dark-red light may be used in caupi bean seeds, although the effect of pre-treatments on seeds is reduced over storage time.