Vineyard Canopy Management
Assessing Canopy Characteristics
Some of the more commonly used characteristics for assessing the canopy are shoot density, leaf layer number, shoot length, lateral shoot development, and pruning weight.
Shoot density is defined as the number of shoots per linear foot of canopy. A lower number of shoots results in an unnecessarily open canopy and a loss of yield potential.
Leaf Layer Number
Leaf layer number (LLN) is determined by the point quadrant method. In this method, a thin, straight metal rod is randomly inserted through the canopy in the fruiting zone and the number of contacts made during each insertion is recorded. Multiple areas within the canopy should be assessed, at least 50 to 100 times in order to get good, representative data (Smart and Robinson, 1991).
Shoot length is another easily used characteristic. Shoots should be from 13 to 15 nodes long on low cordon systems such as the VSP (Allen, 2011).
Lateral Shoot Development
Lateral shoot development is an indication of vine vigor. Large numbers of laterals per shoot indicate high vigor levels and can result in excessive shading within the canopy.
Pruning weight as discussed in the previous chapter is a good indication of vine vegetative growth and can be used to determine crop load as well as the adequacy of the trellis system to handle vine vigor.
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