Effects of water stress on yield and yield components of selected African landrace tomato (Solanum lycopersicum) accessions and commercial varieties

Drought stress is one of the major constraints to enhancement of tomato (Solanum lycopersicum) productivity in Kenya. There exists a wide range of water stress tolerant tomato landraces in Africa that could be harnessed to improve the current available commercial varieties for adaptability to limited moisture conditions. A study was conducted to evaluate the yield and yield components responses of 10 African landraces and five widely grown Kenyan commercial tomato varieties. Greenhouse grown tomato plants were subjected to three water levels, i.e., 100% field capacity (FC), 70% FC and 40% FC, in a randomized complete block design with three replications. Number of fruits per plant, total fruit weight per plant, average single fruit weight, fruit length and fruit weight were determined. Data collected were subjected to analysis of variance using Genstat version 15 and means were separated using least significant difference test at (P<0.05). Results showed that tomato genotypes varied significantly (P<0.05) in fruit yield parameters studied. The landraces VI005895, VI006840 and VI005871 compared well with the commercial varieties particularly in the total fruit weight per plant and average single fruit weight aspects with VI005895 being similar to the leading commercial variety with respect to average single fruit weight . Water stress significantly (P< 0.05) affected the genotypes as reduction of watering level from 100 % FC to 70 % FC to 40 % FC caused a general decrease in yield components such as total fruit weight per plant. Projects for development and improvement of tomato varieties for drought tolerance can objectively exploit the genetic variance among genotypes especially the superior ones that performed well in comparison with the commercial varieties in the market.