Uptake patterns of soil‐applied ⁴⁵Ca and ³²P in some legume species as influenced by differential trifluralin placement

Abstract

Summary: The effect of localized placement of trifluralin on uptake patterns of soil‐applied 45Ca in vetch (Vicia sativa L.), pea (Pisum sativum L.) and soybean (Glycine max) and 32P in vetch and pea was investigated in two soil zones in the roots and in the shoot zone before and after plant emergence. When trifluralin was in the upper root zone severe inhibition of lateral roots occurred as well as a marked decrease in uptake of 45Ca and 32P from this zone. Root growth in the lower zone was unaffected, but uptake of 45Ca and 32P was slightly reduced. Compensatory adventitious root growth as well as a marked increase in uptake of 45Ca and 32P occurred in the shoot zone. Neither root growth nor uptake of 45Ca or 32P in the upper root zone were affected by the presence of trifluralin in the lower root region. When trifluralin was placed in the shoot zone after plant emergence, adven‐titious roots on the shoots were inhibited and uptake of 45Ca and 32P was reduced.