Slow induction of fluorescence of bean leaves on their treatment with $КН_{2} РО_{4}$ solutions

The effect of $КН_2Р0_4$ solutions on the induction changes in bean leaf fluorescence has been studied using different methods of plant treatment: via the root system or by introducing the solutions into the leaf vein. It has been shown that irrespective of the method of treatment, the maximal changes in fluorescence induction occurred at a $10^{-5}- 10^{-4} М$ concentration of the $КН_2Р0_4$ solution. The dependence of the parameters of slow induction of fluorescence on time after phosphate treatment of the leaf has been studied. A positive correlation between relative fluorescence quenching in the course of slow induction and the stationary rate of photosynthesis has been established.