Variation in the number of tuberous cassava roots as a function of air temperature and rainfall

Abstract

Many factors can influence the number of storage roots per plant (NR) in cassava. In order to verify a possible influence of temperature and precipitation on variations recorded in the NR of cv. Prata, in a sandy soil, regression and linear correlation studies were carried out. A significant inverse correlation was observed between NR and total rainfall in the first three months after planting, and a strong correlation (R = ‒ 0.87) between NR and the total number of days with rainfall greater than 10 mm in the 45 to 85 days after planting (DAP) stage. This inverse relationship may be related to leaching of nutrients in the soil and/or decreased sunlight. Significant and negative correlations were also obtained between NR and average temperatures in October and November. The average maximum temperature of the first 40 DAP explained 53% of the variations in the number of tuberous roots (R = ‒ 0.73), possibly due to physiological stress caused by high air and soil temperatures or water deficiency. It is suggested that additional studies be carried out under controlled cultivation conditions to confirm the results presented. If these results were confirmed, the use of mulch, irrigation or additional fertilization after heavy rains may be management methods to be adopted.