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72 WINES&VINES February 2017 GRAPEGROWING PRACTICAL WINERY & VINEYARD Eichhorn-Lorenz phenological scale is an ordinal scale rather than a continuous scale, and an analysis of variance is not valid with ordinal data. There was k e e n i n t e r e s t i n o b s e r v i n g whether or not there was a sig- nificant interaction between pruning date and vine treatment (separate vines or same vine). Fruit maturity samples (whole cluster) were collected twice: one week and four weeks after vérai- son was completed (EL 41) in late-pruned treatments. The sam- ples were analyzed for Brix, pH and titratable acidity (g/L). An analysis of variance was used to evaluate treatment differences with JMP software. Support for assumption of phenological autonomy The median phenological stage of shoots on spurs pruned early was always higher than on spurs pruned late for either the same vine or separate vines (see "Me- dian Eichhorn-Lorenz Phenological Stages" on this page ). The results show that season-long difference in phenological development of shoots are related to bud break date, which has been observed in a previous trial. 6 Earlier bud break led to earlier bloom and véraison. M. Keller and J.M. Tarara demonstrated that persistent season-long differences in shoot development including phenologi- cal development on one grapevine are related to differences in bud break date. 4 In their study, differ- ences in bud break on the same vine were established by differen- tial forced-air heating treatment of spurs on the same vine, whereas in this trial bud break differences were established by pruning date. Statistical analysis of median phenological stage for treatment (separate vines, opposite cordons or alternate spurs), pruning date (early or late) and the interaction between treatment and pruning date (see "Probability of Logistic Regression" on page 73) revealed that there was no significant dif- ference in median phenological stage between treatments at any point of the season. But there was a highly significant difference be- tween shoots on early pruned spurs compared to shoots on late- pruned spurs for every date that phenology was assessed. There was no significant in- teraction between treatment MEDIAN EICHHORN-LORENZ PHENOLOGICAL STAGES Mar 23 Apr 6 Apr 20 May 4 May 18 Jun 1 Jun 15 Jun 29 Jul 13 Jul 27 Aug 10 Modified EL Stage 45 40 35 30 25 20 15 10 5 0 Median Eichhorn-Lorenz phenological stage of early and late-pruned spurs on separate vines (SV), opposite cordons (OC) and alternate spurs (AS) in 2015. SV Early SC Late OC Early OC Late AS Early AS Late EL Stage 38 - 50% Véraison EL Stage 23 - 50% Bloom ONLINEMARKETINGSYSTEM Wines Vines Analytics Visit winesandvines.com/OMS or call 866.453.9701 to set-up your free demo. Reach Thousands of Winery Decision Makers The Wines & Vines Online Marketing System is designed to help your business: • Increase sales • Generate winery leads • Manage clients and sales territories • Improve marketing effectiveness