Edaphoclimatic and genetic influence on soil water availability factor for different sugarcane varieties

Abstract

Sugarcane is grown in all Brazilian states; however, water stress is the main limiting factor of crop productivity in most farming environments (FEN). Thus, the objective was to verify the water availability factor in the soil (factor f) between FEN and sugarcane varieties. The assay was conducted in the Central and Southern Regions of Goiano, in Red Latosol with distinct physical-water attributes among the FEN. Three varieties of sugarcane - Vs (CTC4, RB966928 and RB867515), five factor f (0.41; 0.46; 0.66; 0.72; and 0.84), and two cultivation environments (Goianésia and Quirinópolis), in a sugarcane plant cycle (2019/2020) were evaluated. The randomized block design was used in a factorial scheme (3x5x2), with four replications. The physiological variables (liquid photosynthesis - Lp, stomatic conductance - Sc, leaf transpiration - Lt and temperature gradient leaf atmosphere - TGLA), ton of stalk per hectare - TSH, total recoverable sugars - TRS, ton of POL per hectare - TPH, sugar and alcohol. They were submitted to the F test, mean comparison and quadratic regression. The Sc, Lt and Lp differed statistically between themselves and between FEN, when submitted to the same factor f and Vs, reflecting in penalty in TSH and POL, TRS , sugar and alcohol. Indicating that factor f varies, both between FEN and between Vs. CTC4 has higher productive potential than other Vs; however, more sensitive to soil water depletion (lower factor f), reflecting lower Lp and TSH in both FEN. The factors of soil water availability to avoid water stress were 0.5, 0.49 and 0.47 for RB867515, RB966928 and CTC4, respectively, in Quirinópolis; and 0.47, 0.47 and 0.44 for RB867515, RB966928 and CTC4, respectively, in Goianésia