Interplanting banana at high densities with immature rubber crop for improved water use

Consumptive water use of the rubber/banana intercropping systems was assessed. Five systems were tested; sole rubber (R) and banana (B) crops and three intercrops comprising additive series of one (BR), two (BBR) and three (BBBR) rows banana to one row of rubber. Planting density of rubber remained constant across the treatments, hence the rate of transpiration associated closely with the planting density of banana with ca. 140% increase from banana-rubber to banana-banana-banana-rubber intercrops. Although water use efficiency (WUE) at whole stand basis was comparable among treatments, water use efficiency of component rubber during the latter part of the experiment increased by 118% in intercrops compared to that of the sole crop. Amount of water transpired even in the banana-banana-banana-rubber intercrops was small by comparison to the water received from rainfall, hence in wet tropics with heavy rainfall, agricultural systems should be designed to enhance the productivity through increase water use with less emphasis on water use efficiency