Biomass production and physiological indices of sugarcane cultivars in different soil subunits

Abstract

Sugarcane production is carried out in the fields surrounding 49 sugar mills, where there is heterogeneity of soils at the parcel level, which affects the productive potential of established cultivars. The objective was to evaluate the biomass, the leaf area index (IAF) and the normalized difference vegetation index (NDVI) of the CP 72-2086 and Mex 69-290 cultivars in two ratoon cycles and two soil subunits (Fluvisol eutric, FLeu and Vertisol eutric, VReu), and the relationship indexes with biomass and climatic variables. The results showed that biomass and LAI were affected by the cycle and by the soil subunit associated with the cultivar. Ratoon 1 1 presented higher number of stems (NT), LAI and biomass than ratoon 2 cycle. By soil subunit, CP 72-2086 presented a higher NT and IAF in FLeu than Mex 69-290. The highest stem biomass of CP 72-2086 was in FLeu, and of Mex 69-290 in VReu. Pearson’s correlations were high and significant between NDVI with IAF (0.61); and the IAF, with stem (0.55), foliage (0.57) and total (0.66) biomass. It is concluded that the productive potential of a cultivar is associated, in addition to the genotype effect, to the effect of the soil subunit, which should continue to be evaluated at the plot level in other crop cycles.