The biomass accumulation (cormels and total plant dry weight), yield (fresh weight and number of cormels) and "Metsubure" incidence in taro cormels was evaluated on plants submitted to distinct potassium (K) fertilizer rates, with and without calcium (Ca) application. The experiment was conduced in a glasshouse from 10/19/2002 to 07/20/2003, with the taro 'Chinês' (BGH 5928). Five K levels (0; 150; 300; 600 and 1,200 mg K2O kg-1 of soil), and absence or presence of Ca (0 and 232 mg Ca dm-3 of soil), were evaluated in a 5 x 2 factorial scheme, disposed in completely randomized design, with four replicates. The biomass accumulation and taro yield presented the same behavior in response to K rates, with and without Ca application. Biomass accumulation and yield maximum values were obtained at K2O rates of 794 and 760 mg kg-1 with Ca addition, respectively. Under low K supply, corms dry weight, total plant dry weight, cormels fresh weight and cormels number were higher in the absence of Ca application; this trend was inverted when K2O rate reached 85; 46; 202, and 578 mg kg-1 of soil, respectively. Without Ca application, increased K rates led to increasing in cormels Ca contents; on the other hand, independently of Ca application, cormels K contents increased with the increasing in the K rates. Only without Ca application and K2O rates of 600 and 1,200 mg kg-1 of soil were observed 6.56 and 9.84% of "Metsubure" incidence in taro cormels, respectively.
Colocasia esculenta; mineral nutrition; physiological disorder; eddoe
