The effects of phosphate supply on uptake of potassium ions, 2,4‐D and atrazine by wheat and maize

Abstract

The uptake of the auxin‐type herbicide 2,4‐D and of the non‐auxin‐type atrazine into seedlings of maize (Zea mays L.cv. SZeTC 505) and wheat (Triticum aestivum L.cv. GK Szeged) was investigated, as were their effects on the growth and K+ uptake under different nutrient conditions. A brief incubation of the roots in 0.01 mM 2,4‐D caused a marked herbicide influx only in the absence of Pi. Lowering the Pi concentration of the uptake solution led to an increased 2,4‐D influx into the roots, thereby inhibiting K+ uptake, growth and dry‐matter production of the plants. In the case of 0.01 mM atrazine, Pi‐supply in the external solution influenced neither the herbicide uptake nor the growth of the plants.