Efecto de la posicion de la estaca, niveles de control de malezas y arreglo espacial sobre competencia entre malezas y yuca y el rendimiento de la yuca, variedad M Col 22

Research was conducted at the Centro Internacional de Agricultura Tropical (CIAT) in 1980 in order to solve the problem of low cassava yields in Loja, Ecuador, Objectives were: (1) to determine the effect of vertical and horizontal plantings of cuttings on the emergence and competitive vigor of cassava; (2) to determine the effect of 3 levels of weed control on the cost of each practice and on cassava yields; and (3) assess the effect of spatial arrangements on the competitive ability of cassava regarding weeds, keeping a constant population. A total of 3072 cuttings, of var. M Col 22 were used in a split-plot design with 12 treatments and 4 replications. Treatments were: 1 x 1 m and 0.7 x 0.7 m spacings for populations of 20,000 and 20,408 plants/ha, resp.; vertical and horizontal planting positions; and weed control: (a) weeding at 3O days; (b) 3 weedings at 3O,60, and 9O days; and (c) preemergent control + one weeding. The percentage of germination, coverage/crop and coverage/weed, yield and its components, DM and starch contents were determined. The highest av. yield (40.2 t/ha) was obtained with vertical planting in the 0.7 x0.7 m system with just one weeding. No differences were observed among yields regarding the different levels of weed control. It was concluded that a good cultural control of weeds and good yields can be obtained with var. with little or intermediate vigor if they are planted in quadratic arrangements and in high populations. (CIAT)