Relationship Between Tissue Zinc Levels and Maturity Period of Field Beans

Most bean varieties (Phaseolus vulgaris) are susceptible to zinc deficiency and, if grown where zinc deficiency occurs, are invariably listed among those crops with the greatest need for zinc fertilization (1, 2, 3, 4). Bean plants with mild to moderate zinc deficiency symptoms early in the growing season may recover and produce essentially a normal yield. However, as several individuals have observed (1, 2, 3) this early-season zinc deficiency invariably results in delayed maturity. This is a critical factor in geographical areas where beans may be damaged by fall rains or early frost. The research reported here establishes quantitative relationships between the zinc level in bean tissues and the number of days required for maturation. The results support previous observations of delayed maturity when bean plants have inadequate zinc during early growth