|Author:||Toit, P. G. du ; Dry, P. R. ; Loveys, B. R.|
|Book Group Author:||NA|
Partial root zone drying (PRD) is an irrigation management technique designed to reduce water use in grapevines without a decline in yield, thereby increasing water use efficiency. Experiments were conducted during 2000/2001 in the Coombe vineyard (Waite campus, Adelaide, South Australia) with cv. Cabernet Sauvignon, where the PRD grapevines were irrigated with half the amount of water as the control grapevines, and with cv. Shiraz, where the PRD grapevines received the same amount of water as the control grapevines. PRD treatments showed no significant differences in yield or berry composition at harvest, except that the PRD grapevines that received half the amount of water had significantly smaller berries than the control grapevines. Cabernet Sauvignon PRD grapevines receiving half the amount of water as the control grapevines showed a 34% reduction in main shoot growth and up to a 74% reduction in lateral shoot growth. Shoot growth was inhibited to a lesser extent in Shiraz PRD grapevines receiving the same amount of water, with a 20% reduction in main shoot growth and a 33% reduction in lateral shoot growth. PRD also significantly reduced stomatal conductance in Cabernet Sauvignon, on average, by 31 and 16% in Shiraz. Nitrate reductase (NR) activity in leaves was significantly reduced in response to PRD, irrespective of the amount of water applied. The reduction in NR activity was closely correlated with the development of the PRD cycle and the associated reduction in stomatal conductance.
|Pages:||43 - 54|
|Journal:||South African Journal of Enology and Viticulture|
assimilation, chemical composition, crop yield, cultivars,enzyme activity, enzymes, fruits, grapes, growth, irrigation, leafconductance, leaves, nitrate reductase, nitrogen, plant composition,plant water relations, roots, shoots, stomata, varietal reactions, wateruse, water use efficiency, Australia, South Australia, Vitis, Vitisvinifera, Vitis, Vitidaceae, Rhamnales, dicotyledons, angiosperms,Spermatophyta, plants, eukaryotes, Australasia, Oceania, DevelopedCountries, Commonwealth of Nations, OECD Countries, Australia, chemicalconstituents of plants, cultivated varieties, grape, Vitaceae, watering,Horticultural Crops (FF003) (New March 2000), Plant Breeding andGenetics (FF020), Plant Composition (FF040), Plant Water Relations(FF062), Soil Water Management (Irrigation and Drainage) (JJ800)(Revised June 2002) [formerly Soil Water Management]