The effect of fertilizers on the levels of nitrogen, phosphorus, protease, and pectase in healthy tobacco leaves.

Boiled or dried leaves have generally been used in obtainihg the data already in the literature on the effect of fertilizer treatment on nitrogen and phosphorus levels in tobacco leaves (Vickery, Pucher, Wakeman & Leavenworth, 1940; Ward, 1942). In addition, much work has been done on cured material. In the work reported in this paper methods of fractionation were such that sap and fibre fractions were obtained from fresh material. Nitrogen and phosphorus determinations were made on all fractions, and, in addition, the levels ofprotease and pectase were determined on some.