The Effect of Phosphorus and Potassium Deficiencies on Transpiration in Tea ( Camellia sinensis )

The effect of phosphorus and potassium deficiencies on transpiration in tea ( Camellia sinensis L. Clone DT 1) was studied. The plants were grown in sand culture, and measurements were made after the plants showed phosphorus or potassium deficiency symptoms. The overall growth of plants was reduced by potassium deficiency but not by phosphorus deficiency. Both deficiencies reduced stomatal aperture and increased leaf water potential. Stomatal density decreased in phosphorus deficient leaves and it increased in potassium deficient leaves. The transpiration of whole plants was reduced by both deficiencies. The relative sensitivity of transpiration to water stress was increased by potassium deficiency but not by phosphorus deficiency.