Cassava plant population and leaf harvesting effects on the productivity of cassava-rice intercrop on the upland in Sierra Leone. (67)
Keywords:Cassava, Leaf harvest, Cassava-rice, Productivity, Sierra Leone
AbstractAn experiment was conducted to determine the appropriate cassava plant population to be intercropped with rice and the time of first harvesting of the cassava leaves for improved productivity of the intercrops. The cassava variety 80/40 was planted at four plant populations (3333, 6666, 10 000, and 13 333 plants ha-1) in mid-May of 1996 on the upland in Sierra Leone. The cassava was intercropped with the rice variety Rok16 at a spacing of 25 cm x 25 cm one month later. For each of the cassava populations, there were four leaf harvesting regimes: no leaf harvesting and first leaf harvesting at two, three, and four months after planting (MAP). Subsequent leaf harvesting was done after every two months. A total of three leaf harvests were carried out for each regime. The results revealed that root and leaf yield of cassava did not significantly increase after 10 000 plants ha-1. Grain yield of rice decreased as intercropped cassava plant population was increased from 6666 to 13 333 plants ha-1. Harvesting the cassava leaves at 2 and 3 MAP which was at mid-vegetative stage and panicle initiation stage of intercropped rice, respectively, resulted in similar rice grain yield which was significantly higher than when first leaf harvesting was at 4 MAP cassava, which was at late flowering stage of the rice. Tuberous root yield of cassava increased as the time of first leaf harvesting was delayed from 2 to 4 MAP. The highest net return was obtained when rice was intercropped with 10 000 cassava plants and leaf harvesting started at 3 MAP.