Response of watermelon (Citrullus lanatus thumb. Musf.) to drip and furrow irrigation under different nitrogen and plant population levels

Abstract

Two field experiments were conducted to study the effect of nitrogen, spacing and method of irrigation on watermelon in terms of growth, yield and water use. Growth parameters increased with increase in nitrogen levels up to 180 kg/ha. Fruit yield increased with nitrogen levels up to 120 kg N/ha (370 q/ha in 1984 and 345 q/ha in 1985) as compared to 60 kg N/ha (349 q/ha in 1984 and 308 q/ha in 1985). Reducing the row spacing from 300 cm to 200 cm increased the fruit yield from 336 q/ha to 389 q/ha in 1984 and from 303 q/ha to 336 q/ha in 1985. Fruit yield was higher under drip irrigation (418 q/ha in 1984 and 379 q/ha in 1985) as compared to furrow irrigation (307 q/ha in 1984 and 287 q/ha in 1985). Fruit yield was highest with irrigation at 1.00 IW/CPE ratio (338 q/ha in 1984 and 310 q/ha in 1985) and the lowest with irrigation at 0.25 IW/CPE ratio (327 q/ha in 1984 and 252 q/ha in 1985). Drip irrigation with one emitter per two plants recorded higher yields (367 q/ha in 1984 and 314 q/ha in 1985) than irrigation at 5.0 cm depth (269 q/ha in 1984 and 227 q/ha in 1985) in furrows. Nitrogen level of 120 to 140 kg/ha was found to be optimum for obtaining high yields in watermelon. A plant population of 16,666 plants/ha (200 cm x 60 cm) was found to be ideal for yield maximization. Drip irrigation with daily application of water at the rate of 25% pan evaporation is suitable for realizing higher yields. Furrow irrigation at 0.50 or 0.75 IW/CPE ratio with 2.5 cm depth of water can be adopted for watermelon for higher yields. Thus, nearly 50% saving in water was possible under drip irrigation, as compared to furrow irrigation.