Biometric attributes and sugarcane productivity under full irrigation: effects in the third ratoon

Abstract

The sugarcane crop is of extreme importance for the country, either for the production of sugar, ethanol, and in the generation of electricity. It is grown throughout Brazil, mainly in the State of SP. Some studies indicate that water availability in the soil for sugarcane can be considered as the main causative factor of productivity climate variability, culture cycle after cycle. In this work, we are set two hypotheses: the first is that there are more productive variety grown in water restriction, and the second is that among the cultivars there is one that responds best under cultivation conditions in the absence of water restriction, or under irrigation. From these hypotheses defined that the main objective of this proposal is to evaluate the development, production and technological quality of five varieties of sugarcane under full irrigation and non-irrigated cultivation in the third ratoon crop. The experiment is installed in the Demonstrative and Experimental Area of Irrigation FCAV, UNESP, Jaboticabal, SP. In the experimental area is being cultivated five cultivars of sugarcane in irrigated and non-irrigated conditions. The five cultivars analyzed are: CTC 4, IACSP93-3046, RB86-7515, IACSP95-5000 and IAC91-1099. The irrigation system is the drip, which are buried in the planting row and 30 cm depth. The management of irrigation is adopted via climate with weather data and precipitation obtained daily. In the third ratoon crop, irrigation is conducted whenever there is an accumulated water deficit of 20 mm culture. The treatment without irrigation receive only rainwater. To evaluate the crop response to treatment, biometric parameters are analyzed: stem height, stem diameter, number of green leaves and tillering. At harvest will be the technological parameters evaluated: Pol% juice, total soluble solids (Brix), Pol% cane, purity, fiber and total recoverable sugar (ATR) and also the cane yield and sugar per hectare. The experiment will be two factors: Irrigated (I) and non-irrigated (NI), with 12 repetitions. These factors are allocated in the plots and the varieties are allocated to the subplots. The experimental design is in balanced incomplete block (BIB) with three varieties per plot. (AU)