Effect of Pruning Mechanization on Vine Performance and Fruit Composition of Chardonnay Grapevines Under Warm Climate Conditions in the San Joaquin Valley of California
Experiments conducted so far revealed that most of the parameters of yield components and fruit composition are significantly affected by pruning mechanization. Number of nodes retained and shoots was comparable for mechanical pruning and minimal pruning while hand pruned vines had fewer nodes and shoots. Light penetrating into the fruiting zone was greater in minimally pruned vines, compared to hand or mechanical pruned vines. Number of clusters and yield were higher in minimally pruned vines than that in hand or mechanically pruned vines. Clusters were smallest in minimal pruned vines and largest in hand pruned vines while mechanical pruning produced medium cluster size. Maturity was delayed by 9 days in mechanical pruning and by 34 days in minimal pruning, compared to hand pruning. Brix and pH of harvested fruit were also different among the treatments. Juice pH was much higher and TA was much lower in minimally pruned vines when Brix was comparable. Full bloom petiole N, P, and Mn were affected by pruning mechanization. Higher content of N, P, and Mn was found in hand pruned vines than that in mechanically or minimally pruned vines. Minimally pruned vines had higher Mn content which was comparable to hand pruning. Other mineral nutrients were not affected by pruning mechanization.
