Effects Of Black Plastic And Straw Mulch On Yield And Water Use Efficiency Of Cucumber

Field experiments were conducted during the 1995 and 1996 seasons to evaluate the yield and water use of cucumber (Cucumis sativus L. cv, 'Calypso', 1995 and 'Dasher IT, 1996) grown with black plastic and grass straw mulch under 3 levels of drip irrigation. Cucumber was grown in replicated plots arranged in randomised complete block design and mulched with cither black plastic (L25 mil) or dry guinea grass (Panicum maximum L.) straw (5,0-6.5 cm thick). Plots were drip-irrigated at soil water tensions corresponding to 20,40, and 60 kPa. Number of marketable fruits, fruit size, total weight of fruits and marketable yield were recorded for each harvest In 1995, for all of the measures parameters, black plastic mulch resulted in significantly higher values than the straw mulch. Marketable yield (15.7 t ha"1) in plots with black plastic mulch was significantly higher (P<0.005) than plots with straw mulch (11.9 t ha'1). For both mulches, drip irrigation levels had no influence (P>0.10) on cucumbcr yield and yield components. Water use in straw-mulched plots was lower than plastic-mulched plots, but water use efficiency and economic returns to irrigation water were higher in plots with black plastic mulch. The incidence of fusarium wilt (Fusarium sp.) in plots with straw mulch was higher than plots with plastic mulch, a contributing factor for low yields in straw-mulched plots. In 1996, there were no significant differences observed between mulch treatments or irrigation regimes for any of the parameters measured. Production from the Dasher 11' cultivar was much higher than the yields obtained in 1995 from 'Calypso',