Harvest extended over 5 weeks, from 23 August to 2 October, a week longer than 2006. The range of yield was large, from 3.2 kg/vine to 22.7 kg, or 2.7 ton/acre to 18.2 tons (Table 3). The potential yield was even higher had there been no losses to rot or shrivel. Percent crop loss differed greatly from zero to 70%. But most of the varieties either had none or less than about 5%crop loss (13 out of 20). Cluster numbers differed from about 40 to 65. We strive to leave similar bud numbers (15 shoots/m) in order to obtain similar cluster numbers, however this is not always possible. When we obtain shoot number at pruning, we will ascertain whether clusters number differences are due to different clusters initiated per shoot or to different shoot numbers per vine. Cluster wt differed dramatically from a low of 119 g (Carmenere) to 494 g (Cinsaut). Cluster wt was driven by both berries per cluster and berry wt. Berries per cluster ranged from a low of 72 (Carmenere) to a high of 250 g (Tannat) and berry wt from a low of 1.2 g (Petite Verdot) to a high of 3.4 g (Cinsaut).
In 2007, we harvested sound clusters from defective. Unlike 2006, however, we separately accounted for rot vs. shrivel. Five cultivars had rot levels of 4-6 clusters per vine (about 10%) while the rest had 0 to 2 clusters. Severe losses were evident due to shrivel was 37 clusters in Souzao and 15 clusters in Durif. By shrivel we mean the physiological disorder where the cluster rachis dries and the berries completely shrivel. In these clusters there is not sign of rot and the cause of this disorder is unknown. Thirteen cultivars showed no signs of shrivel at all.
Brix ranged from about 21 to more than 25. Most pH values were 3.7 and higher. However a few varieties stood out in 2007 as having a reasonably high ripeness level including (Brix, pH): Aglianico (23.4, 3.41), Montepulciano (22.7, 3.30) and Tannat (25.2, 3.61). Two of those had reasonable yields and relatively low loss (yield [t/a] and loss %): Aglianico (12.6 and 4.2%) and Montepulciano (10.5 and 0%).
Thanks to work by Larry Williams, we were able to better control growth by judicious use of irrigation regime.