A Study of the Relationship Between Drought Resistance and Root Growth of Three Cultivars of Common Beans (Phaseolus Vulgaris)

Abstract

A study was carried out to investigate the relationship between the depth of root penetration and drought resistance in three cuitivars of common beans ( Phaseolus vulgar is I,. ) , name1y Glp 2 ( rosecoco ) , GLP x-92 (Mwi teman la) and CLP 1004 ( Mwez i Moja ) . The varie ties have been recommended for high, low to high, and low rain fall areas , respectively. A technique which involves herbicide placement at a given depth in the soil and monitoring of the herbicide toxicity symptoms on the above ground organs was used to evaluate root penetration. The bean cuitlvars were studied and compared at three different irrigation love Is. Four experiments were carried out, two in the glasshouse and two in the field. The glasshouse experiments showed that all the cultivars were similar in their sensitivity to < herbicide. A bioassay test carried out showed that there was no upward or downward movement of this herbicide In the field. The glasshouse experiment agreed with the field experiment in I, hat, in both eases CLP 10 04 had the highest root penetration rate . In the field total amount of water applied was inversely related to the root penetra tion rate (RPU) in all the cultivars....