Drought Resistance In Sugar Cane Varieties In Mexico.

Sugar cane is import as an ingredient of the human diet and as an alternative energy. In Mexico 61 percent of sugar cane planted is rainfed. There is a drought period from November to May (Great Winter Drought, GWD), another drought period happens between June and October (Intra Summer Drought, ISD). Global Climatic Change causes variations in duration and intensity in these drought periods. To have an initial idea about drought resistance variability of the best ten commercial sugar cane varieties four experiments were established, two at the slope of occident of Mexico (L1 and L2) and two at the slope of the Gulf of Mexico (L3 and L4). Planting dates were September 13, August 24, September 21, and December 15, 2011.Three drought levels were used S0 irrigated during GWD 2011-12, S1 without irrigation from March until end of GWD and S2 without irrigation at the GWD. Variables related to borer damage, plant grow, chlorophyll, canopy temperature, brix, and industrial quality was determined. Reduction in plant population at L1 was 25.1 %, related to damage of borer (Diatraea sspp). Other reductions were in plant height (20 %), chlorophyll (21.7 %), and length of millable cane (29.2 %). In L2, reduction in plant height was 29.3 %, chlorophyll 21.8%, harvestable stem 33.4, Brix 5.1 %. In L3 the reduction was 13.3 % in plant height, chlorophyll 5.3 % and harvestable stem 15.4 %. In L4 there was not effect of drought. There are evidences of variability in the genetic material studied.