Deficit irrigation as alternative of management to increase productivity of sugarcane cultivars: effect in the fourth ratoon

Abstract

The sugarcane crop is of extreme importance for Brazilian agribusiness. It is cultivated throughout Brazil. Although sugarcane is adapted to the conditions of high temperature and relative water scarcity, studies indicate that the water content in the soil is the main restriction for maintenance and increase of productivity and that sugarcane cultivars have different responses to soil water deficit and irrigation management. The interaction genotype versus environment is an important source of variation in yield in sugarcane. Studies indicate that there are cultivars that represent greater productive potential under irrigated conditions. Irrigation management under the condition of water scarcity may become a common practice in the coming decades, mainly due to the scarcity of water and the expansion of the irrigated area. Deficit irrigation is defined as the application of water below the requirements required by the crop being an important management technique for irrigated agriculture, which aims to increase the efficiency of water use. Therefore, the main objective of the present proposal will be to evaluate the development, production and technological quality of sugarcane cultivars in the fourth ratoon under cultivation without irrigation and under deficit irrigation. The present experiment will be installed in the experimental area of FCAV, UNESP. In this place is cultivated the five varieties of cane used in this proposal. The irrigation system used will be dripping, which are buried under the planting line. The deficit irrigation will be performed whenever there is accumulated water deficit of the 20 mm crop. To evaluate the response of the crop to the treatments, biometric parameters, technological qualities and productivity will be analyzed. In this study five sugarcane cultivars will be analyzed, which are CTC 4, IACSP93-3046, RB86-7515, IACSP95-5000 and IAC91-1099. The experiment will consist of two factors: irrigated (I) and non-irrigated (NI), with 12 replicates. These factors will be allocated in the plots and the varieties will be allocated in the subplots. The experimental design will be in incomplete balanced blocks (BIB) with three varieties per plot. (AU)