Yield and quality response of processing potato variety 'Royal' to water stress during vegetative and tuber bulking growth stages

• Main Author: Fekadu Gebretensay Mengistu(Student)
• Format: Publication
• Language: English
• Published: Denmark University of Copenhagen 2009
• Subjects: AGENT DE LEST; BULKING AGENTS; http://www.fao.org/aos/agrovoc#c_1146; http://www.fao.org/aos/agrovoc#c_16500; http://www.fao.org/aos/agrovoc#c_7998; MATERIA VOLUMINOSA; POTATO PRODUCTS; PRODUCTOS DE LA PAPA; PRODUIT A BASE DE POMME DE TERRE; TUBERCULE; TUBERCULO; TUBERS

The effect of water stress, which measures 80-100kpa soil water tension,was studied on potato (solanum tuberosum L.) variety 'Royal' by exposing plants to the stress for temporary periods during vegetative (10DWSV or 15DWSV)or tuber bulking stages (10DWSTb or 15DWSTb) or fluctuated (repeated) water stress (WSF) covering the whole growing period from the onset of the stress.Plant hight and stem numbers were affected by the stress at vegetative stage, whereas Tuber yield was affected at both vegetative and tuber bulking stages and the effect increased when the stress was extended from 10 to 15 days being the highest yield reduction (40%) was caused by water stress fluctuation (WSF).However, the number of tubers produced per plant and tuber size distribution were not affected by the stress and did not implicate any relation with the variations in yield.More importantly, tubers' quality paramters such as specific gravity, dry matter, and starch concentration were significantly affected by the stress in that, water stress fluctuation (WSF) caused the highest reduction effect followed by 15 and 10 days water stress duration (15DWSTb and 10DWSTb respectively) at tuber bulking stage.Similarly, the concentration of tubers' reducing sugar (glucose)and sucrose were increased by the stress at tuber bulking stage,even though the increase in reducing sugar did not cause significant variations in the formation of brown color (sugar end) on potato slices during frying,which was confirmed by the non-significant differences between the measured L*, a* and b* values for each water stress treatments.