ABSTRACT Light is a determining factor in plant morphophysiology, as it influences the growth and development of agricultural crops. Thus, the objective was to investigate the effects of light sources on the growth and development of “biquinho” pepper cultivars. The experiment was performed in two stages (Exp1 and Exp2), evaluating two cultivars (BRS Moema; Airetama biquinho) in five light sources (white LEDs, red LEDs, blue LEDs, red/blue LEDs, and fluorescent lamps). In Exp1 the plants were kept in a controlled condition, with a completely randomized design, in a 2x5 factorial scheme (cultivars x light sources) until 76 days after emergence (DAE), in which growth variables and photosynthetic pigments were evaluated. In Exp2, the plants were removed from the above conditions and transplanted in pots, being kept in greenhouse for more 76 DAE. At 152 DAE, the same variables as Exp1 were evaluated, as well as gain of shoot fresh and dry mass, and gain of root fresh and dry mass. In both experiments, growth variables were affected by cultivar and the light sources, however, the behavior did not follow the same trend for all variables, indicating that the light quality influences the growth of the crops, and impacting during greenhouse conditions.

Abstract The aim of this work was to evaluate the effect of five light qualities [fluorescent lamps (FL); white (WL), red (RL), blue (BL), or red/blue LEDs (RBL)] and two types of flask sealing (with or without porous membranes) in the in vitro germination and growth of two Capsicum frutescens cultivars (Espaguetinho and Cayenne). For this, two seeds were inoculated per flask (350 mL) containing 50 mL of MS medium with 100 mg L-1 myo-inositol, 30 g L-1 sucrose, 6.0 g L-1 agar, and pH 5.8 ± 0.1. The plants were kept under culture room conditions (16-h photoperiod, 25 ± 2°C and irradiance of 40 μmol m-2 s-1). The experiment was arranged in CRD, 2x5x2 factorial scheme (Cultivar X Light qualities X Sealing type). At 42 days, the following traits were evaluated: percentage of germination; root and shoot length; number of green leaves, senescent leaves and nodal segments; and fresh and dry weight. Plants grown under RL and BRL, showed greater number of green leaves, and longer shoots and roots. The use of porous membranes remarkably reduced the number of senescent leaves. Thus, the use of porous membranes, RL and BRL are recommended since they improve growth and development of pepper in vitro.