Different nutritional deficiencies or toxicities may limit bean development and yield. N and P deficiencies are the most frequent, although deficiency of minor elements and Al/Mn toxicity can reduce yields considerably.

Research of the physiology section was centered on identifying the characters associated with high root yields and quality in cassava under stress conditions. Plant reaction to water stress was studied, specifically regarding growth and yields of var.

Efforts to develop cassava technology for the vast areas of acid infertile soils were continued Large-scale germplasm screening in the field was begun in Carimagua for tolerance to low levels of P and acidity and in Quilichao, for tolerance to low levels of P.

De rol die voorlichting kan spelen bij het landinrichtingsbeleid, wordt in sterke mate beinvloed door het feit dat het belang dat dit beleid tracht te dienen gewoonlijk slechts ten dele overeenstemt met hetgeen de betrokkenen als hun belang zien.