Sugarcane phenology under the phosphorus effect

Author(s)

Carlos Suguitani

• Document type: Master's Dissertation
• Press: Piracicaba. , gráficos, tabelas.
• Institution: Universidade de São Paulo (USP). Escola Superior de Agricultura Luiz de Queiroz (ESALA/BC)
• Defense date: 2002-01-22
• Advisor: Sizuo Matsuoka
• Field of knowledge: Agronomical Sciences - Agronomy
• Indexed in: Banco de Dados Bibliográficos da USP-DEDALUS
• Location: Universidade de São Paulo. Biblioteca Central da Escola Superior de Agricultura Luiz de Queiroz; t633.61; S947f; 78885

Abstract

The harmonious interaction between environment x variety determines sugarcane productivity. There are some research work related to adubation, but there are still lack of biometrics data related to the sugarcane phenology under different phosphorus levels, and total deficiency related to the modern varieties of this culture. This is a very important knowledge to determine the plant ecophisiology and correct maneuver of this culture. Because of that we tried to establish biometrics measurements of the phenology of four (4) modern sugarcane varieties - RB835486, RB835054, RB855113 e RB855536- under differentiated phosphorus leveals, and establish physiological index resulting from the interaction genotype x environment. The evaluated parameters were high, tillering, leaf dynamic (green leaves and emerged), leaf area, and index of leaf area), productivity, brix, cane pol% and fiber. The samples were installed in two different places: UFSCar (São Carlos Federal University)-campus Araras, and experimental station of UFSCar in Valparaíso. The interaction results between levels and varieties in the samples were not significant in almost all of the evaluations. The experiment founded differences are related with the media of varieties. In general, was verified that the biggest vegetative growing on each plant occurs from November to April, and the most intense tillering between August to November. The tillering, on each plant, were more intense from July to November, and the varieties RB8551153 and RB855536 were the ones that presented the biggest population. These same varieties were the ones which obtained biggest productivity in Araras, but in Valparaíso the RB855536 variety presented smaller production comparing to the others. In relation to next cicle, the biggest plant growing was during the period from December to march, because of the rainy period that precede and happens during this period of months. Associating the period of sampling with the accumulated percentage of the phytomass, it was observed that 20% of the fresh total mass ocurrered from July to December, 50% to 60% from December to March, and 20% to 30% from March to the harvest (AU)