Issue link: http://winesandvines.uberflip.com/i/946131
62 WINES&VINES March 2018 GRAPEGROWING WINE EAST "biofix" date. This makes sense so long as the indicator date is con- sistent for predicting the emer- gence of the pest each year. In a project I worked on at Texas A&M University, we concluded that male grape berry moth emergence in the Gulf Coast region of Texas was between 456 and 517 GDD after bud burst of Blanc Du Bois, a common commercial bunch grape in that region. Models such as these can be developed in new and existing grapegrowing re- gions, but not without careful re- cords of grapevine phenology to accompany insect trapping data. What are the most important phenology stages to record? The exact number of phenology stages or "events" to record will vary depending on the objectives of the grower. The most complete grapevine phenology chart was developed by Dr. K.W. Eichhorn and Dr. D.H. Lorenz in 1977. It was modified in 1995 by B.G. Coombe and then revised in 2004 by P. Dry and Coombe in what is commonly known as the Modified Eichhorn- Lorenz (E-L) system. The E-L sys- tem applies a numerical category for each advancement in grapevine growth. View the modified E-L sys- tem at winesandvines.com/fea- tures/article/196082. Researchers still use the origi- nal E-L System when collecting phenology data. However, the ab- breviated version is much more practical for commercial use. Eight major stages are listed on the Mod- ified E-L system that I, as a viticul- tural consultant, recommend all growers record: bud burst, shoots reaching 10 cm, flowering begins, flowering, setting, berries pea size, véraison and harvest. A graphical comparison of these current phe- nology events overlaid on that of the previous seasons can serve as an aid in predicting the timing of the next stage, based on historical comparison relative to accumula- tion of GDD. Factors affecting phenology In general, newly planted vines or vines in their third leaf or younger may demonstrate phenology trends that are not consistent with observa- tions in established vines (fourth leaf or older). Young vines tend to have shallower root systems that are more sensitive to fluctuating conditions in the soil surface, including tempera- ture and moisture. I have observed vineyards of mixed varieties coming into their second leaf that had bud burst dates very close to each other in varieties that normally would dif- fer in bud burst dates by as much as 10 days in mature vineyards. Fur- EASTERN WINE LABS Serving the Analytical needs of East Coast Wineries WWW.EASTERNWINELABS.COM Ph 609-859-4302 Cell 609-668-2854 chemist@easternwinelabs.com AOAC Member Basic Hoe comes with a Hillup and a Takeaway Blade. Additional attachments include .3 Tooth Cultivator, Undercutter Blade, Rotary head, " NEW " Rolling Cultivator and "Vine Auger". The Green Hoe Company, Inc. 6645 West Main Road, Portland, NY 14769 PHONE (716) 792-9433 FAX (716) 792-9434 WWW.GREENHOECOMPANY.COM GREEN GRAPE HOE Grape inflorescence shows various stages of flowering including caps on flowers, caps off with exposed flowers and early fruit set (Modified Eichhorn- Lorenz Stage 25).