Modeling Of Cotton Growth And Yield In Commercial Area In Bahia Cerrado

Growth analysis and yield of crops are key to evaluate the interaction of crops with the environment and agricultural practices. In this study, assessments of cotton growth and yield were carried out in a commercial production system in rainfed regime, submitted to two different sources of nitrogen in in the municipality of Luis Eduardo Magalhaes, State of Bahia, Brazil. The aim was to assess the fit of logistic and exponential models, the growth variables cotton and the leaf area index, due to cumulative degree-days (CDD). During the period from 11/2014 to 07/2015 of the following biometric parameters observations were made: plant height, total biomass, biomass of stems, leaves and reproductive structures. The logistic and exponential models, fitted according to the CDD, were able to satisfactorily represent the variation of the evaluated biometric parameters, with a fitted regression coefficient (R-ajs(2)) between 0.88 and 0.99. The average yield of cotton ranged between 5263.4 and 3891.5 kg ha(-1) and the plume yield between 2300.1 and 1688.9 kg ha(-1). It is concluded that the fitted model may be used to aid in the plant growth analysis when related to the CDD, besides enabling to obtain biometric coefficients in dynamic models.