Effects of organic fertilizers on growth, yield, quality and sensory evaluation of red lettuce (Lactuca sativa L.) ‘Veneza Roxa’

Abstract

Lettuce (Lactuca sativa L.) is one of the widely used salad vegetable in Swaziland. However, there is a dearth of information pertaining to organic lettuce production. An experiment was conducted in a lath house at the Horticulture farm, Luyengo Campus of the University of Swaziland to assess the effects of organic fertilizers on yield and quality of lettuce grown in river sand. The organic fertilizers used were (a) bounce back compost, (b) cattle manure and(c) chicken manure. The rates of application were 40 tones per hectare (t/ha) for chicken and cattle manures, 1.5 t/ha basal dressing and 1.0 t/ha side dressing for bounce back compost. Inorganic fertilizers 2:3:2 (22) + 0.5 % zinc (Zn) and limestone ammonium nitrate (LAN 28%) were included at specific application rates of 955 kg/ha basal dressing and 100 kg/ha side dressing as control. The results showed that type of fertilizer applied significantly (P 0.05) differences in appearance and taste among treatments. Results of this experiment showed that inorganic fertilizers were less suitable in lettuce production in river sand when compared to organic fertilizers. It is recommended that lettuce can be grown successfully using organic fertilizers.