Agronomy
The results of regional trials for promising cassava var. under uniform improved technology are given. Trials were conducted in Media Luna, Chigorodo, Carimagua, Rio Negro, San Martin, CIAT- Palmira, CIAT-Quilichao, and Caicedonia. In 7 of the 8 sites, var. M COL 1684, CM 342-55, and CM 489-1 outyielded the best local clones. Var. M COL 1468, M COL 1684, and M COL 22 tested over 45, 40, and 40 cycles, resp. have produced weighted av. yields of 29.1, 30.8, and 22.0 t/ha, resp. Yields of the 1st 2 are both high and relatively stable while yields of M COL 22 are lower and unstable. The Centro Internacional de Agricultura Tropical tested and simplified the single leaf-bud cutting technique for the international transfer of cassava var. in a joint project with Philippine workers. Trials were conducted on chemical weed control in cassava in monoculture and in mixed cropping systems. The response to N-P-K fertilization in cowpea/cassava intercrops was determined. Studies were conducted to determine the effect of chemical treatments and storage duration of cuttings on germination, early growth, and canopy formation. (CIAT)