Abstract
Vines of Vitis vinifera L., varieties `Pinot noir' `White Riesling', and `Sauvignon blanc', were covered from approximately mid-July to mid-September with one of two types of plastic Saran shade material which reduced the total solar radiation to either 30 or 21% of full sunlight.
Reduced light delayed fruit maturation 1 to 5 weeks. The total accumulated calories of solar and sky radiation required for the maturation of fruits from `White Riesling' and `Sauvignon blanc' vines grown under 30% sun averaged 16% and 20% less, respectively, than the energy required for the maturation of grapes grown in full sunlight. Total acidity and concentration of malates in mature `Sauvignon blanc' fruits grown under 30% sun were approximately 20 and 13% greater, respectively, than in fruits of similar maturity from vines grown under full sun. The concentration of tartrate of 21 and 30% sun fruits were nearly equal, whereas the concentration of malate was slightly higher in the 21% sun fruits. The average fresh weights of berries from 30% and from 100% sun vines were approximately the same; however, average fresh weight of berries was usually slightly less for 21% sun vines than for vines receiving higher light intensities. The maturation and composition of `Sauvignon blanc' fruits from vines covered 2 weeks before vérasion were not significantly different from fruits of vines covered at vérasion.
- Accepted May 1967.
- Published online January 1967
- Copyright 1967 by the American Society for Enology and Viticulture
Sign in for ASEV members
ASEV Members, please sign in at ASEV to access the journal online.
Sign in for Institutional and Non-member Subscribers
Log in using your username and password
Pay Per Article - You may access this article (from the computer you are currently using) for 2 day for US$10.00
Regain Access - You can regain access to a recent Pay per Article purchase if your access period has not yet expired.