Grapevine Rootstock Selections

A team of academic, government, and industry partners developed a plan to evaluate rootstock selections from a USDA­ARS rootstock breeding program. In winter 2013-14, potential rootstock selections were assessed for desirable mother vine traits, including the production of abundant, well-matured canes of adequate diameter, length, and internode spacing, with minimal lateral shoot growth, powdery mildew scars, freeze damage, or fruit production. Based on these criteria, 240 vines having very poor traits were identified and discarded, and 30 selections with very good traits were prioritized for further evaluation. In spring 2014, cuttings from the high-priority selections were distributed to several academic and industry labs, where their rooting ability, nematode resistance, and virus status were tested. These tests narrowed the high priority list to six selections (PC0349-11, PC0349-30, PC04153-4, PC0597-13, PC0784-334, and PC0790-37) which rooted adequately and were resistant to aggressive strains of root-knot nematodes (RKNs). PC0790­37 tested positive for SyV-1 and RSP viruses, so it was forwarded to Foundation Plant Services for virus elimination; testing on that selection will resume after clean plant material becomes available. Most of the remaining selections were eliminated because they were insufficiently resistant to RKN, or they rooted poorly in both labs. Four additional rootstock selections (PC0333-5, PC0366-27, PC03155-47, and PC0495-51) were added to the high priority list based on the performance of Syrah when grafted to those stocks. In 2015, cuttings from the highest-priority selections were distributed to the cooperators to confirm rootability and RKN resistance. Based on those results, cuttings from six superior selections (PC0333-5, PC0349-30, PC0349-11, PC04153-4, PC0495-51, and PC0597-13) were judged worthy of advancing to field trials to assess their performance as grafted plants in commercial vineyards.

 

Evaluation of Grapevine Rootstock Selections

A team of academic, government, and industry partners developed a plan to evaluate rootstock selections from a USDA­ARS rootstock breeding program. In winter 2013-14, potential rootstock selections were assessed for desirable mother vine traits, including the production of abundant, well-matured canes of adequate diameter, length, and internode spacing, with minimal lateral shoot growth, powdery mildew scars, freeze damage, or fruit production. Based on these criteria, 240 vines having very poor traits were identified and discarded, and 30 selections with very good traits were prioritized for further evaluation. In spring 2014, cuttings from the high-priority selections were distributed to several academic and industry labs, where their rooting ability, nematode resistance, and virus status were tested. These tests narrowed the high priority list to six selections (PC0349-11, PC0349-30, PC04153-4, PC0597-13, PC0784-334, and PC0790-37) which rooted adequately and were resistant to aggressive strains of root-knot nematodes (RKNs). PC0790­37 tested positive for SyV-1 and RSP viruses, so it was forwarded to Foundation Plant Services for virus elimination; testing on that selection will resume after clean plant material becomes available. Most of the remaining selections were eliminated because they were insufficiently resistant to RKN, or they rooted poorly in both labs. Four additional rootstock selections (PC0333-5, PC0366-27, PC03155-47, and PC0495-51) were added to the high priority list based on the performance of Syrah when grafted to those stocks. In 2015, cuttings from the highest-priority selections were distributed to the cooperators to confirm rootability and RKN resistance. Based on those results, cuttings from six superior selections (PC0333-5, PC0349-30, PC0349-11, PC04153-4, PC0495-51, and PC0597-13) were judged worthy of advancing to field trials to assess their performance as grafted plants in commercial vineyards.

 

Field Evaluation of Wine Grape Rootstocks

As growers are aware, rootstock performance is highly dependent on site, with the most significant component appearing to be soil type, followed by vineyard spacing, and farming practice. When sites have few limitations rootstocks tend to perform more uniformly than when sites or farming practices are marginal. Rooting depth and water availability also seem to play a significant role.

Rootstocks such as 110R and 1103P have performed better than other rootstocks in sites where soil types are coarse-textured and/or where irrigation is sparingly applied. 1103P generally yields about the same as 110R but responds with more growth. Growth of both can be excessive in deep, well drained soils. 110R responds poorly to water-logged soils. The rootstocks 3309C and 101-14Mgt are clearly more moderate in vigor, often about 60 to 70{aed9a53339cdfc54d53cc0c4af03c96668ab007d9c364a7466e3349a91bf0a23} of 110R. In side-by-side comparisons, 101-14 is generally slightly more vigorous than 3309 but not in all conditions. Both are recommended for moderate to moderately high vigor sites. The rootstock 420A was generally low in vigor. Although it has comparable yield to other rootstocks if pruned to similar bud numbers per vine, the resultant growth is 20 to 50{aed9a53339cdfc54d53cc0c4af03c96668ab007d9c364a7466e3349a91bf0a23} of the more vigorous rootstocks. It could only be recommended for sites where vigor potential is high or where the vine spacing is very close. The Teleki hybrids 5C and 5BB are moderately vigorous in most sites except where water stress is present. Both tolerate heavy, poorly drained soils better than other rootstocks, provided there is no threat of Phytophthora.

Other rootstocks included in the trials were Freedom, Harmony, St George, 1616C and O39-16. Readers are encouraged to consult the full report for in-depth details about the trial sites and the individual rootstock recommendations.

PDF: Field Evaluation of Wine Grape Rootstocks

Field Evaluation of Wine Grape Rootstocks

This project continues rootstock evaluation for winegrape performance in a wide range of coastal and foothill production areas, and in sites which are infested with phylloxera, nematodes or both, or which have important site/soil conditions or limitations. This project includes sites in Amador, Napa, San Luis Obispo, Sonoma, Mendocino and Monterey Counties. At all sites we see significant differences in the performance of the rootstocks that will lead us toward more informed better rootstocks decisions.

Two sites in Amador County both have Zinfandel as the scion variety. These sites not only represent our on Zinfandel sites but the only ones in the granitic soils common to the Sierra Foothills. The first site is unique in that it is a non-irrigated site. We have reported data from this site since 1995. In terms of relative yield performance, we have seen that over time 1103P has distanced itself from the other rootstocks and 3309C has fallen behind. The second trial contains 14 rootstocks. The 2000 yield data followed the 7-year trend and 5BB had the greatest yield and O39-16 the least. The yield difference was driven by differences in both berries per cluster and cluster number.

At our Cabernet Sauvignon rootstock trial in Mendocino County we are able to look at the effect of the nematodes and their populations often increases over time. The highest yielding rootstock found in 2000 as well as in the multi year data was 110R with 8.6 and 13.4 kg vine-1 respectively and the lowest in 2000 and in the multi-year data was 101-14 with 1.8 and 5.8 kg vine-1 respectively. The 2000 data we present in our report will be coupled with nematode population data that will be collected this spring and another year of performance data in 2001.

In our report we present data from 5 sites where 2000 was the first or second year of data collection. These vineyards are all young and during the initial years of data collection we need to look at year-to-year data to establish developmental stability. Yield and pruning weight data in subsequent years will be used to establish developmental stability. Three sites are located in the Napa Valley. The first site is Merlot located mid-valley near the Silverado Trail, with well-drained, quite cobbly soil. This is only the second year in which we have collected data in this trial. For the two remaining Napa Valley sites, Chardonnay in the Carneros region and Cabernet Sauvignon near Calistoga, and 2000 was the first year of data collection. Data from two additional first year sites is also reported. One is a non-irrigated Pinot noir site in San Luis Obispo County that showed quite a bit of yield variability and lastly we have a Chardonnay site in Sonoma County. All of these sites represent opportunities to collect rootstock data from new varieties and/or conditions and will add significantly to our rootstock knowledge base.

PDF: Field Evaluation of Wine Grape Rootstocks

Field Evaluation of Wine Grape Rootstocks

This project continues rootstock evaluation for winegrape performance in a wide range of coastal and foothill production areas, and in sites which are infested with phylloxera, nematodes or both, or which have important site/soil conditions or limitations. This project includes sites in Amador, Napa, San Luis Obispo, Sonoma, Mendocino and Monterey Counties. At all sites we see significant differences in the performance of the rootstocks that will lead us toward more informed better rootstocks decisions. Two sites in Amador County both have Zinfandel as the scion variety. These sites not only represent our on Zinfandel sites but the only ones in the granitic soils common to the Sierra Foothills. The first site is unique in that it is a non-irrigated site. We have reported data from this site since 1995. In terms of relative yield performance, we have seen that over time 1103P has distanced itself from the other rootstocks and 3309C has fallen behind. The second trial contains 14 rootstocks. The 2000 yield data followed the 7-year trend and 5BB had the greatest yield and 039-16 the least. The yield difference was driven by differences in both berries per cluster and cluster number. At our Cabernet Sauvignon rootstock trial in Mendocino County we are able to look at the effect of the nematodes and their populations often increases over time. The highest yielding rootstock found in 2000 as well as in the multi year data was 110R with 8.6 and 13.4 kg vine” respectively and the lowest in 2000 and in the multi-year data was 101-14 with 1.8 and 5.8 kg vine’1 respectively. The 2000 data we present in our report will be coupled with nematode population data that will be collected this spring and another year of performance data in 2001. In our report we present data from 5 sites where 2000 was the first or second year of data collection. These vineyards are all young and during the initial years of data collection we need to look at year-to-year data to establish developmental stability. Yield and pruning weight data in subsequent years will be used to establish developmental stability. Three sites are located in the Napa Valley. The first site is Merlot located mid-valley near the Silverado Trail, with well-drained, quite cobbly soil. This is only the second year in which we have collected data in this trial. For the two remaining Napa Valley sites, Chardonnay in the Carneros region and Cabernet Sauvignon near Calistoga, and 2000 was the first year of data collection. Data from two additional first year sites is also reported. One is a non-irrigated Pinot noir site in San Luis Obispo County that showed quite a bit of yield variability and lastly we have a Chardonnay site in Sonoma County. All of these sites represent opportunities to collect rootstock data from new varieties and/or conditions and will add significantly to our rootstock knowledge base.

Field Evaluation of Wine Grape Rootstocks

Napa 4 was lost when the plot was night machine-harvested in error. Napa 5 was determined to be too immature to yield acceptable data in 1999. A revised Final Report will be submitted when the additional data is available. Amador 1. Fox Creek. The 1999 data slightly favored putative drought resistant rootstock 1103P over the rootstock 3309C more so than the long term average (1995-1999, Table 3b). However, none of the yield components individually were significantly different enough to account for the observed yields. Thus the site variability which has manifested itself in this trial before continues to show. Amador 2. Sutter Home. Yields in 1999 were about at the long term average, 1994-1999. The 1999 data followed the 6-year trend with 5BB having the greatest yield and 039-16 and 101-14 having the least. There were differences in cluster number, berries per cluster and berry wt contributing to the yield differences. Napa 3. Duckhorn Vineyards. This is a new trial near the Silverado Trail, mid-valley with well-drained, quite cobbly soil. The 1999 data (Table 4) show that 3309C is out-yielding other rootstocks by 0.5 to 1.3 kg per vine. Napa 4. Oakville Experimental Vineyard. Teleki 5C, 225 Ruggeri and 1103P lead the yield column while S04 and Kober 125AA are among the lowest yielding. Berries per cluster and berry wt are the yield components playing the most important role, although the component clusters per shoot also is involved. Shoot wt (relating to shoot length) is dramatically different varying from a low of 35 g (S04) to 110 g (1103P), resulting in dramatic differences in pruning wt, from a low of 1.4 kg/vine (101-14Mgt) to a high of almost 4.0 (1103P).

Field Evaluation of Winegrape Rootstocks

Rootstocks vary in their performance from site to site. A report on the past 10 years of rootstock trials is being prepared to show the trends and contrasts among the trials. In this report, long-term averages of rootstock productivity and growth will be presented; this will give the basic production information. Following that, rootstocks will be examined individually and compared across sites. This analysis will show whether rootstocks perform consistently across sites and production systems; where they do not, a closer examination of site and practice will be done. Finally, correlation coefficient tables will be presented to search for the inter-relatedness of various components. It is hoped that this in-depth examination will give growers more insight to choosing rootstocks for their conditions.

Field Evaluation of Winegrape Rootstocks

Data are presented for 12 rootstock trials throughout northern and coastal California and one trial from Kern County. The data indicate that there were wide variations in rootstock growth and yield components in these sites. Generally, growth differences (measured at pruning wts) were due to shoot wt (i.e. length) more than shoot number. Yield differences were due to berries/cluster, berry wt and cluster number, the importance of any one component varying among plots. Bloomtime petiole N and K also varied substantially among rootstocks. Juice potassium also differed significantly but no apparent relationship with petiole potassium or juice pH was noted. It is unclear from these data whether the differing performance of rootstocks from plot to plot is due to interactions of rootstock with site, scion or cultural practices. Readers are encouraged to consult the 1996 AVF Final Report to find data on the performance of particular rootstocks or in specific sites.

Field Evaluation of Winegrape Rootstocks

Data on rootstock performance is presented for 13 trials, ranging from Ukiah to Amador to Bakersfield. Rootstock recommendations tend to be site specific so readers are urged to obtain a copy of the complete report. In general, the rootstock 110R is performing well in the dry-farmed site while Teleki 5C and Kober 5BB tend to do well in heavier soils well supplied with water. The rootstocks 3309C and 101-14 Mgt tend to be moderate vigor rootstocks in some situations but can be vigorous when used in fertile sites with plenty of water. The 420A is a lower vigor rootstock. These experiments point up the interaction between rootstock performance and grower management practice. Two of the VR rootstocks trials have been concluded and have supported the hypothesis that VR 039-16 is the only recommended rootstock for sites with fanleaf degeneration complex. This recommendation is holding as well for plots in the northern, central and southern San Joaquin Valley, although more data are needed in those sites. Future trials will focus on interactive effects of rootstocks with other cultural practices such as vineyard floor management, water availability and vineyard spacing.

Field Evaluation of Winegrape Rootstocks

The objective of this project is to evaluate rootstocks for winegrape performance in a wide range of coastal, foothill and central valley production areas, and in sites which are infested with phylloxera, nematodes or both, or which have the potential for such infestations. In 1992-93, 9 rootstock trials were harvested. A total of 16 trials are mature enough for harvest in 1993-94. The VR hybrid rootstock trials in Alexander Valley and San Jose, indicate that the rootstock VR 039-16 is the best rootstock for sites infested with fanleaf degeneration complex. Improved vine growth and yield as well as decreased rate of fanleaf infection are seen for 039-16 in both sites. At this point there are no other rootstock recommendations which could be made for fanleaf sites. Recommendations for planting 039-16 outside of fanleaf sites cannot be made until more is known about phylloxera resistance mechanisms and the risk posed by this one-half vinifera rootstock. In other experiments, rootstocks seem to be showing site x genotype interactions. This is especially true for Teleki 5C and 110 Richter. In deep, fertile soils well supplied with water, 5C shows itself to be quite vigorous, producing about 0.8 lbs cane prunings/ft row versus 110R at less than 0.4 lbs. However, in a hillside site, 110R is one of the top-ranked rootstocks in both growth and yield. These types of site interactions mean that multiple trials will be necessary to help choose an appropriate rootstock for the wide range of coastal and northern production sites. Details of individual trials are given in the full report.