Nutritional and Physiological Response of Sugarcane Varieties to Nitrogen Fertilization in a Haplic Cambisol

In order to assess the nutritional and physiological response of sugarcane varieties COLPOSCTMEX 05-223, COLPOSCTMEX 06-039, RD 75-11, COLPOSCTMEX 06-271, MEX 69-290, COLPOSCTMEX 06-2362, MEX 68-P-23 COLPOSCTMEX 472, ATEMEX 96-40 and CP 72-1210 to nitrogen doses of 0, 120 and 180 kg ha−1, foliar N, P and K, chlorophyll content, photosynthesis rate (A), transpiration rate (E) and stomatal conductance (gs) were recorded for 150 days. The study was conducted in fields of sugar factory Azsuremex (IA), Tabasco, Mexico, during the growing season of 2014/2015, under rainfed conditions with Haplic (silty–eutric–calcaric) Cambisol. No variation was observed among the sugarcane varieties studied, in terms of the nitrogen doses applied, foliar N and P. Foliar K concentrations were deficient in all varieties (0.55–0.80 %). The dose of nitrogen did not affect chlorophyll concentration or photosynthesis rate in any variety, but it had an effect on gs and E. Under conditions of increasing photosynthetically active radiation, the variety ATEMEX 96-40 was performed better than the varieties COLPOSCTMEX 05-223 and RD75-11B in terms of A, gs, internal CO2 concentration (Ci) and transpiration rate (E).