The effect of overhead netting on water utilization and soil water content of a table grape vineyard
The use of hail netting as a requirement for the successful cultivation of table grapes is an accepted practice in the northern summer rainfall region of South Africa.
Recently there has been a growing interest in cultivating table grapes under netting in the Western Cape and the Lower Orange River area.
The purpose of the trial was to obtain parameters, which can be used for irrigation scheduling of table grape vineyards under netting and thus, the effect of overhead netting on water utilization and soil moisture content was investigated.
A six-year-old vineyard at the ARCs experimental farm at Roodeplaat (25°35South; 28°21East, 1164 m above sea level) was used.
Vines of four Vitis vinifera L. scion cultivars grafted onto Jacquez clone 5/8/4 were planted (3,0×1,8 m spacing) on a Hutton soil and trained onto a Trentina trellis with black hail netting (20% shade effect, with a diamond mesh size of 8×8 mm of high-density polyethylene filament and lint). Irrigation was applied by micro jets and scheduled according to crop factor adjusted evaporation rates using a Class A evaporation pan.
Standard viticultural practices were applied during the growing season.
The trial was laid out as a combined split-plot randomized block design.
Every cultivar block was laid out as a randomized block design.
Hail net treatments were allocated completely randomized within each cultivar block, with four replications.
Netting (20%) decreased transpiration rate (-4.0%) and evaporation (-15.5%) significantly.
Leaf temperature decreased significantly under hail netting, whereas ambient temperature was only slightly decreased.
Gravimetric water content of the soil decreased under netting.
The increased leaf water potential and leaf water content, as well as the lower transpiration rate, evaporation and soil water content under netting, indicate that irrigation requirements under netting are reduced compared to conditions of direct sunlight.
Avenant, J.H. and Avenant, E. (2022). The effect of overhead netting on water utilization and soil water content of a table grape vineyard. Acta Hortic. 1335, 627-634
DOI: 10.17660/ActaHortic.2022.1335.79
https://doi.org/10.17660/ActaHortic.2022.1335.79
DOI: 10.17660/ActaHortic.2022.1335.79
https://doi.org/10.17660/ActaHortic.2022.1335.79
water use, leaf water content, leaf water potential, transpiration, evaporation
English
1335_79
627-634