Sugarcane yield estimation for climatic conditions in the state of Goiás

Estimativa da produtividade agrícola da cana-de-açúcar para as condições climáticas do centro-oeste goiano

ABSTRACT

Models that estimate potential and depleted crop yield according to climatic variable enable the crop planning and production quantification for a specific region. Therefore, the objective of this study was to compare methods to sugarcane yield estimates grown in the climatic condition in the central part of Goiás, Brazil. So, Agroecological Zone Method (ZAE) and the model proposed by Scarpari (S) were correlated with real data of sugarcane yield from an experimental area, located in Santo Antônio de Goiás, state of Goiás, Brazil. Data yield refer to the crops of 2008/2009 (sugarcane plant), 2009/2010, 2010/2011 and 2011/2012 (ratoon sugarcane). Yield rates were calculated as a function of atmospheric water demand and water deficit in the area under study. Real and estimated yields were adjusted in function of productivity loss due to cutting stage of sugarcane, using an average reduction in productivity observed in the experimental area and the average reduction in the state of Goiás. The results indicated that the ZAE method, considering the water deficit, displayed good yield estimates for cane-plant (d > 0.90). Water deficit decreased the yield rates (r = -0.8636; α = 0.05) while the thermal sum increased that rate for all evaluated harvests (r > 0.68; α = 0.05).

Key words:
agricultural planning; Saccharum spp.; yield prediction model.