Jan 25, 2013 - According to a March 2011 report provided by the U.S. Wine. Institute, record high 2010 wine shipments ma
COMMERCIAL HORTICULTURE SERIES
Agriculture & Natural Resources
TIMELY INFORMATION Feasibility of Growing Pierces Disease Resistant Vitis vinifera Grapes Within the High Disease Pressure Southeastern Region Dr. Elina Coneva, Fruit Crops Specialist, Alabama Cooperative Extension System January 25, 2013
Current nutraceutical research revealed grapes are a powerful source of phytochemicals and antioxidants and very beneficial to human health. This breakthrough information triggered an increased market demand for fresh fruit and processed grape products. According to a March 2011 report provided by the U.S. Wine Institute, record high 2010 wine shipments make the U.S. the world's largest wineconsuming nation. Although Pierce’s Disease (PD) is a serious threat to the cultivation of grapes in the United States, especially in warmer southern regions, recently the U.C. Davis grape breeding program has developed new hybrids consisting of 87.5% V. vinifera progeny and are resistant to PD. These newly developed selections are expected to produce high quality yield even in regions with high PD pressure, such as the southeastern U.S., where the Vitis vinifera production was previously not a viable option. The objective of our study was to assess the feasibility of growing PD resistant V. vinifera selections in Alabama and the southeast.
An experimental vineyard was established at the Chilton Research and Extension Center (CREC), AL, in 2010 to study the feasibility of growing Pierce’s Disease resistant Vitis vinifera (French type, or European) grapes within the high disease pressure southeastern region. The experimental vineyard consisted of three recently developed PD resistant 87.5% V. vinifera selections namely 502-10, 502-01, and 501-12. The vines were trained to a vertical shoot positioning (VSP) system and a supplemental drip irrigation was provided to facilitate vine establishment. The grape selections grew well in 2011 season and set a good crop of fruiting clusters which were removed from the plants in an attempt to provide optimal conditions for the growth and development of the vine root system and enhance the vine vigor and longevity. In 2012 the three V. vinifera selections produced their first commercial crop. A number of measurements were collected to evaluate the vegetative growth, productivity, and fruit quality of the newly introduced selections. To determine the pruning weight and aid in defining the optimal current season crop load, all of the one-year-old pruned wood per vine was collected and weighed when the vines were dormant pruned. Our results shown in Fig. 1 suggest that selection 502-10 had the lowest pruning weight of 0.75 kg/vine, while 501-12 produced 1.1 kg pruning weight.
Figure 1. Pruning weight of PD resistant V. vinifera selections grown at the CREC, Clanton, AL, 2012. During the 2012 season, selection 502-10 started to mature in early June and was harvested on July 11th, while 501-12 initiated the veraison in mid-August and ripened late, on September 21st (Fig. 2).
Figure 2. Veraison season of PD resistant V. vinifera selections grown at the CREC, Clanton, AL, 2012. Our results showed differences in total yield/vine during 2012 with the late maturing 501-12 producing the highest crop of 5.8 kg/vine (Figure 3). Bird feeding was
accountable for a considerable crop loss for the early ripening selection 502-10, which required modifications in the existing net coverage method. The minimal adjustments applied to the bird netting were very successful in protecting the mid and late season selections from bird damage.
Figure 3. Total yield per vine of PD resistant V. vinifera selections grown at the CREC, Clanton, AL, 2012. During the 2012 season, selection 501-12 produced the highest number of clusters/vine (76.8), while 502-10 had 12.5 clusters on average (Table 1). Mid-season selection 50201 had the largest cluster weight of 173 g, and mid-season selection 502-01had the largest size berries of 2.98 g. Table 1. Total number of clusters and mean cluster size of PD resistant V. vinifera selections grown at the CREC, Clanton, AL, 2012.
Summary: •
Selection 502-10 (Fig. 4 A) matured early in the season and sustained considerable bird feeding damage. The 2012 pruning weight results suggest it is the least vigorously growing selection from this group.
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Mid-season selection 502-01 produced the largest clusters with the largest berries in 2012 (Fig. 4 B).
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PD resistant selection 501-12 matured late, had the largest number of clusters, the highest yield and the highest soluble solids content (Fig. 4 C). This was the most vigorously growing grapevine selection based on our results of pruning weights.
A
B
C
Figure 4 A, B, C. Fruit clusters of PD resistant V. vinifera selections 502-10 (A), 502-01 (B), and 501-12 (C), 2012.
The preliminary results on the performance of the newly developed PD resistant V. vinifera selections in Alabama are very encouraging. Knowledge gained through this project will aid in development of best management practices and production system recommendations, vital for the establishment of a sustainable grape industry, and enhance the competitiveness of Alabama-grown specialty crops. Our research will aid in introducing locally grown fresh and processed V. vinifera products, rich in antioxidants and resveratrol, and proven to help in preventing cardiovascular diseases, inflammation and aging processes that can contribute to healthier diets for Alabamians. The newly introduced selections are expected to improve the agricultural sustainability of Alabama agriculture and food systems by advancing the environmental and economic sustainability in the state through implementation of advanced technologies that ensure the viability of specialty crop production systems, enhance the quality of life for farmers by providing better profits to the farmer and a valuable healthy food to the customer.
