Effect of Ca, K and B supply on water-stress induced chlorophyll loss from tobacco and cotton leaf discs

Abstract

A study was made of the influence of Ca:K ratios and B levels on the chlorophyll content of tobacco and cotton leaves grown under glasshouse conditions. Excised leaf discs were floated on a solution of polyethylene glycol 6000 to study the breakdown of chlorophyll under stress conditions. The level of B nutrition was found to interact significantly with Ca:K ratios. At the low Ca: high K ratio plants grew well and the application of B retarded chlorophyll breakdown. At the high Ca: low K ratio a K deficiency was observed and the application of B accelerated breakdown of chlorophyll. The chlorophyll content of the leaf discs was much lower after the stress but differences were in the same order.