Perda de produtividade potencial da cultura do sorgo no Estado de São Paulo

ABSTRACT POTENTIAL YIELD LOSS OF SORGHUM CROP IN THE STATE OF SAO PAULO, BRAZIL This study was carried out to estimate the sorghum yield loss for 36 different sowing dates forfour regions of the State of Sao Paulo, Brazil: Manduri, Piracicaba, Ribeirao Preto and Ilha Solteira. TheDoorenbos and Kassam/FAO method was applied to estimate the potential and actual yield. It wasnecessary to use a temperature dependent factor to correct incoherent estimates provide by Doorenbosand Kassam method. Historical series of meteorological data ranging from 10 to 40 years were used toidentify the periods of the year with low risks to sorghum crop, besides the probabilities of losses toeach sowing date. In Manduri, Piracicaba, Ilha Solteira and Ribeirao Preto, the loss risk is minimizedwhen sowing is made between 15 October and 15 November, with losses lower than 5%. For all regions,yeld losses below 5% observed in more than 30% of the years. Key words: Sorghum bicolor, water balance, sowing date, climatic risk.