Project Number
WW 04-10
Project title
Bepaling van die waterverbruik en gewasfaktore van wingerde op die buitegronde van die Benede-Orangeriviervallei
Project leader
Myburgh, P
Team members
Louw, P J E
Project description
Evapotranspiration and crop coefficients of vineyards on the outer soils along the lower Orange river were determined in two separate field trials at Augrabies and Gariep, respectively. Effects of irrigation cycle length on evapotranspiration (ET) as well as yield and quality of table, raisin and wine grapes were investigated. Due to low water holding capacity of the weathered gneiss soil and hot climate at Augrabies, drip irrigation had to be applied daily throughout the season to meet the water requirements of the grapevines. Peak evapotranspiration for drip and microsprinkler irrigation amounted to ca 4.5 mm per day and 8.5 mm per day, respectively. This is probably the highest evapotranspiration for table and dried grape vineyards in South Africa. Microsprinkler irrigation applied at longer intervals, i.e. 3 days in December, resulted in the best yield and quality for table as well as dried grapes compared to 2 day intervals. Although considerably less irrigation water was applied, yield and quality obtained with drip irrigation were inferior compared to micro sprinkler irrigation. Furthermore, daily drip irrigation applied at a low flow rate over the warmest part of the day held no significant advantages over the same amount of water applied at a high drip flow rate before sunrise.
At Gariep, peak evapotranspiration for 7, 14 and 21 day irrigation cycles amounted to 5.5 mm per day, 4.6 mm per day and 4.2 mm per day, respectively. There was no difference in evapotranspiration between 21 day and 28 day irrigation cycles. The longer irrigation cycles tended to reduce vegetative growth and resulted in smaller berries, but reduced yield significantly compared to 7 day cycles. Wine quality tended to increase with irrigation cycle length and the best quality was obtained with irrigation applied at 28 day intervals. This trend was consistent over three seasons.
Presentation(s)
Myburgh, P A and O’Connell, R A. 2000. Seasonal variation in transpiration efficiency of Sultanina grapevines under two micro-irrigation systems. Paper presented at the 6th International Micro-irrigation Congress. 22-27 October, Cape Town, South Africa.
Myburgh, P A. 2001. Effect of irrigation on table grape quality. Irrigation Information Day. 20 March.
Article
Myburgh, P A, Coetzee, F. 2004. Apparatus for non-destructive measurement of grapevine trunk cross sectional area, South African Journal of Enology and Viticulture, v. 21 (1) (p. 67-69)
Myburgh, P A, O’Connell, R A. 2004. Apparatus for non-destructive measurement of grapevine trunk cross-sectional area, South African Journal of Plant and Soil, v. 21 (p. 67-69)
Paper
Myburgh, P A, O’Connell, R A. 2000. Seasonal variation in transpiration efficiency of Sultanina grapevines under two micro-irrigation systems, IN: Proceedings of the 6th International Micro-irrigation Congress: Micro 2000. (p. 1-4) 22-27 October 2000,