Yield and quality of two tomato (Solanum lycopersicum L.) cultivars as influenced by drip and furrow irrigation using waters having high residual sodium carbonate

Abstract

Performance of tomato when irrigated with sodic waters particularly under drip irrigation is not well known. A Weld experiment was conducted for 3 years to study the response of tomato crop to sodic water irrigation on a sandy loam soil. Irrigation waters having 0, 5 and 10 mmol c L i1 residual sodium carbonate (RSC) were applied through drip and furrow irrigation to two tomato cultivars, Edkawi (a salt tolerant cultivar) and Punjab Chhuhara (PC). High RSC of irrigation water signiWcantly increased soil pH, ECe and exchangeable sodium percent- age progressively; the increases were higher in furrow com- pared to drip irrigation. EVect of high RSC on increasing bulk density and decreasing inWltration rate of soil was also pronounced in furrow-irrigated plots. Higher soil moisture and lower salinity near the plant was maintained under drip irrigation than under furrow irrigation. Performance of the two cultivars was signiWcantly diVerent; pooled over 2002- 03 and 2003-04 seasons, PC yielded 38.8 and 30.0 Mg ha i1 and Edkawi yielded 31.8 and 22.9 Mg ha i1 under drip and furrow irrigation, respectively. At RSC10, cultivar PC pro- duced 38 and 46% higher fruit yield than cultivar Edkawi under drip and furrow irrigation, respectively. Reduction in fruit yield at higher RSC was due to lower fruit weight under drip irrigation and due to reduced fruit number as well as fruit weight under furrow irrigation. Decrease in fruit weight was more pronounced in cultivar Edkawi than in cultivar PC. Increase in RSC lowered quality of the fruits except the ascorbic acid content. High RSC under drip irri- gation, in general, had lesser deteriorating eVect on the fruit quality particularly for cultivar PC than under furrow irri- gation. For obtaining high tomato yield and better-quality fruits using high RSC sodic waters, drip irrigation should be preferred over furrow irrigation. Better performance of local cultivar PC compared to Edkawi at medium and high RSC suggests that cultivars categorized as tolerant to salin- ity should be evaluated in the sodic environment particu- larly when irrigated with high RSC sodic waters.