Studies on the mineral nutrition of sweet sorghum. II: uptake and redistribution of radiophosphate

Abstract

This paper deals with the following aspects of the phosphatic nutrition of sweet sorghum: absorption of radiophosphate as influenced by time of uptake and external concentration; comparative foliar absorption of monoammonium and diammonium phosphate both in the presence and absence of urea; redistribution of previously absorbed and stored phosphate. Data obtained herewith allowed for the following conclusions to be drawn: (1) root absorption increased with time of contact, being higher in the case of excised when compared to roots in intact plants; (2) Michaelis and Menten kinetics are applicable to root uptake, the parameters being different for the two types of root material; (3) the two ammonium phosphates showed the same rate of uptake, which was not influenced by urea; (4) P deficient plants showed highes rates of uptake and translocation.