Project Number: 5358-21000-034-30
Project Type: Grant

Start Date: Aug 14, 2008
End Date: Sep 30, 2009

Objective:
1. Determine the optimal rate of FeEDDHA application in reducing leaf chlorosis of Concord vines in central Washington; and 2. Compare the tolerance of different rootstocks to lime-induced chlorosis in terms of vine growth, leaf function and fruiting.

Approach:
We will continue the field trial in the `Concord¿ vineyard that has consistent chlorosis problem in central WA, but will double the rate of application as we used in 2006 and 2007. Leaf samples will be taken at bloom, 1200 degree days (DD) and pre-harvest (early September) to measure leaf chlorophyll concentration, total Fe and active Fe. The severity of foliage chlorosis of each vine will be assessed. Fruit yield and yield components will be determined at harvest. Comparing `Concord¿ vines grafted on to different rootstocks in response to a range of soil pHs in a controlled pH experiment for a second year will provide valuable information on the tolerance of different rootstocks to Fe-deficiency. Two-year-old `Concord¿ vines grafted onto a range of rootstocks will be used. The onset and severity of chlorosis will be assessed throughout the growing season. Leaf photosynthesis, chlorophyll concentration, leaf total Fe and active Fe will be measured. Fruit set, fruit yield, and yield components will be monitored. Total vine growth will be measured after leaf fall. Documents Grant with Cornell University.