A Comparative Study of the Actually Applied and the Predicted Water Requirement for the Potato Crop (Solanum tuberosum) at Shambat, Sudan

Page(s): 9 (1), 69-81,11 RefThis research was carried out in the Demonstration Farm of the Faculty of Agriculture, University of Khartoum, at Shambat, for the two winter seasons of 1992/93 and 1993/94.The study aimed at comparing the optimum quantity of irrigation water required by the potato crop per season and the predicted water requirement by using the modified Blaney-Criddle and Penman equations, based on the meteorological data at Shambat. To determine the optimum requirement of irrigation water, different amounts of water were applied in 1992/93 season (500, 600,700 and 800 mm per growing period) and in 1993/94 season (240, 320, 400, 480, 560 and 640 mm per growing period). Parshal Flume device was used to measure the applied water. Best stem emergence, haulm growth and total yield were obtained with irrigation water quantities ranging from 560 to 600 mm per season applied in 8-10 irrigations. The predicted seasonal water requirement, using Blaney-Criddle and Penman equations, were 450-491 and 475-524 mm, respectively. This means that the predicted water requirement is closer to the optimum range (560-600 mm) detected. Therefore, it is concluded that it would be more feasible to adopt Blaney- Criddle equation to predict the potato crop water requirement, specially under the semi-arid climates, because it is a function of easily measurable weather parameters compared to Penman methodKhartoum University Pres