HOME RESEARCH: ROOT BIOLOGY/VINE NUTRITION Soil pH: Young Vines Soil pH: Mature Vines Wine Grapes, Rootstocks, & Soil pH Concord/Niagara, Rootstocks, & Soil Type Phylloxera CONCORD PRODUCTION Pruning & Juice Quality Vineyard Mechanization Mid-Season Crop Adjustment SEASONAL VINE GROWTH Concord Growth Analysis The 2003 Big Dig SAY WHAT??

Project Title: Improving Wine Grape Production in Acid Soils with Rootstocks and Soil Management © 2003 Principal Investigators   Terence R. Bates Dept. of Horticultural Sciences Cornell University Vineyard Laboratory 412 East Main St. Fredonia, NY 14063 Phone: 716-672-2175 email: trb7@cornell.edu Cooperators   Bruce Reich Richard Dunst Hans Walter-Peterson Dept. of Horticultural Sciences, Cornell, Geneva Vineyard Laboratory, Fredonia, NY Vineyard Laboratory, Fredonia, NY Objectives of Proposed Research: Long-term Objectives Evaluate the interaction of rootstock and soil pH on the vegetative and reproductive growth and juice quality of two V. vinifera and two hybrid scion varieties. Measure the vine tissue nutrient concentrations throughout the season on the different scion, rootstock, and soil pH treatment combinations and develop tissue sampling protocols and management guidelines for the mineral nutrition of highly weathered, acidic soil, cool climate vineyards.

Objectives for the 2003 Season

Apply the soil amendments to achieve the desired soil pH values and establish the vineyard with the grafted plant material ordered from and planted by the nursery in 2002.

Purchase an inductively coupled plasma emission spectrometer (ICP) for the measurement of vine tissue nutrient concentrations.

Justification and Importance of Proposed Research

Acid soils are a detriment to quality wine grape production in viticulture regions of the northeast (Lake Erie and Finger Lakes regions, NY) and northwest (Willamett Valley, OR), US. Selecting a rootstock, such as C3309, may not be based on selecting the best rootstock for the production situation but may be based on selecting the rootstock we have the most information on or experience with. Furthermore, there is little viticulture research information on nutrient management practices for cool climate, acid soil vineyards. Understanding the interaction between scion, rootstock, soil character, and vineyard management choices has the potential of improving both the production and quality of wine grapes in these areas.

Nutrient and Vine Response to Soil pH
One of the objectives in vineyard nutrient management is to improve mineral nutrient availability of naturally occurring elements in the high-rainfall generally-acidic soils of the northeastern and northwestern, US. Soil pH has a dramatic effect on the availability of several essential nutrients for grape production. Low soil pH (pH 5.0 or lower) affects nutrient availability and root growth. As the soil pH decreases from 5 to 3.5, aluminum solubility increases and it is the free and exchangeable aluminum ions that affect nutrient availability and root growth (Marschner, 1986). High free aluminum precipitates phosphorus out of the soil solution, making it unavailable to the plant, and exchangeable aluminum displaces calcium and magnesium, decreasing their availability. Aluminum toxicity can also affect root growth by inhibiting cell division in the root apical meristem (Foy, 1992; Kochian, 1995).

High pH soils, either natural limestone based soils or soils amended through the application of lime, present a different set of nutritional circumstances for grapevine roots. As the soil pH increases from 5 to 8, aluminum insolubility removes it from the playing field which alleviates some of the phosphorus problems and increases the availability of calcium and magnesium. However, iron also precipitates out of the soil solution limiting its availability and excessive calcium and magnesium availability can compete with potassium availability and uptake (Marschner, 1986).

Since 1998, we have been investigating the response of own rooted Concord grapevines to soil pH. A series of experiments on young potted grapevines and a current field trial have provided information on vine growth and yield as well as root physiology and season long tissue nutrient concentrations (Bates et al, 2002). Concord, relatively acid tolerant when compared to V. vinifera or hybrid varities, demonstrated reduced growth and productivity as the soil pH dropped below 5.0. Reductions in root growth and total cation uptake and increases in rhizosphere pH and the impact of phylloxera infection were measured with a decrease in soil pH (Bates et al, 2002). Above a soil pH of 7.0, Concord had decreased vegetative growth, rhizoshere pH, and tissue potassium concentrations.

Under acid soil conditions and with V. vinifera and hybrid varieties, nutrient management would most likely be in the 5.5 to 6.5 soil pH range. In New York, V. vinifera in a 5.5 soil pH or lower suffered from the acid soil symptoms of low vine size, poor production, crown gall, and poor cold hardiness (Pool et al, 1992). Soil pH above 7.0 would be acceptable for V. vinifera production; however, the excessive amount of lime needed to raise the soil pH above 7.0 in acidic vineyards and the low mobility of limestone in soil make the application impractical.

We propose to establish a V. vinifera and hybrid block that focuses on vineyard nutrient management and quality production in the 5.5 to 6.5 soil pH range. This range avoids acid soil issues such as aluminum toxicity and reduced root growth and keeps the lime requirements in a commercially practical and realistic range.

Root Distribution and Rootstock Selection
Root distribution is important in pH adjusted vineyards because of the low mobility of lime in the soil. White Riesling grafted to C3309 at the Cornell vineyard laboratory had poor growth and poor cold hardiness despite seven years of repeated lime applications. When the vines were excavated, root distribution showed that most of the root system was below the horizon of soil influenced by the lime amendments (Figure 1). Therefore, the vines had remained in acidic soil and demonstrated symptoms of acid soil sickness.

Figure 1. Root distribution of White Riesling grafted to C3309 rootstock at the Cornell Vineyard Lab in Fredonia, NY

From a rootstock perspective, there are two potential strategies to this wine grape production problem in acid soils; (1) Find and use an acid tolerant rootstock selection or (2) work with a shallow rooting rootstock that will respond to soil amendments and other floor management practices. We propose to evaluate own rooted vines, and vines grafted to C3309, Gravesac (an acid tolerant rootstock), and Riparia Gloire (a shallow rootstock) under lime and no-lime treatments (Delas, 1992).

Measuring Vine Mineral Nutrition
Soil testing is a tool for monitoring soil pH and estimating nutrient availability. For example, soil tests are valuable in calculating the lime requirement for acid soils. Since grapevine root systems can be spreading and/or relatively deep, tissue sampling is an effective tool in determining the nutrient status of the vine. Soil and tissue tests measure different aspects of vineyard nutrient status. Therefore, the most powerful information for the grower is obtained when soil and tissue samples are used in conjunction with, and not isolated from, each other.

The timing of tissue sampling and the tissue to be sampled for vine nutrient analysis is a reoccurring question in vineyard nutrient management. For example, research by Shaulis showed that leaf tissue and petiole tissue have different potassium concentration patterns during the season (Shaulis 1961). Furthermore, leaf position on a shoot will influence seasonal potassium concentration patterns (Figure 2). Therefore, if tissue samples are going to be consistently and accurately interpreted for the purpose of making fertilizer recommendations, a standard tissue sample is needed so that standard nutrient concentration values can be used for interpretation. For example, a standard recommended potassium concentration for veraison petioles will not be applicable for a grower that sampled leaves or petioles at bloom.

Figure 2. Seasonal patterns in tissue potassium concentrations from sufficient (+K) and deficient (-K) Concord. Patterns are different depending on tissue and location on the shoot (from Shaulis and Kimbal, 1956).

In California, a standard set of values have been established for bloom-time petiole samples (Christensen et al, 1978). In New York, the recommendation for tissue sampling is to collect petioles, 60-70 days after bloom (near veraison), on the most recently mature leaf. It appears this timing/tissue decision was based on practical issues. Tissue potassium concentrations are more stable near veraison, there is less vineyard activity and more time for tissue sampling near veraison, and petioles are an easy standard sample to collect. At least for New York, faster turn around time from the nutrient analysis labs and the desire by growers to have bloom samples for current season fertilizer adjustments has sparked the reexamination of tissue nutrient standards at times other than veraison during the growing season.

In a Concord block with established soil pH values of 4.5, 5.5, 6.5, and 7.5, tissue nutrient concentrations were measured on petioles of the most recently mature leaf from bloom to veraison. This testing showed the pattern for each mineral nutrient throughout the growing season and between the soil pH treatments. For example, there was a difference in the seasonal pattern of potassium and magnesium as well as a difference in the narrow soil pH range of 5.5-6.5 (Figure 3).

We propose to measure season long tissue nutrient concentrations in the wine grape project to determine the interaction of soil pH, rootstock, and scion variety on vine nutrition, productivity, and juice quality.

Figure 3. Seasonal pattern in potassium and magnesium petiole concentrations in Concord vines at 5.5 and 6.5 soil pH.

Outcome and Benefits Expected
From this project we expect to gain a better understanding of the nutrient needs of V. vinifera and hybrid varieties for both vine health and juice quality in acid soils. In conjunction with the current project on the response of Concord to soil pH, we wish to develop more comprehensive cool climate nutrient management recommendations for V. vinifera, hybrid, and V. labrusca varieties. In addition, the integration of rootstock selection and floor management as a tool for increased vine health and productivity is an underused strategy in eastern viticulture that we expect to develop further.

Research Timetable
This project is intended to be a relatively long-term project of eight to ten years. The experimental scion/rootstock combinations were ordered and site preparation was initiated in 2002. Soil pH amendments will be incorporated and the vineyard will be planted in the spring of 2003 with subsequent vineyard establishment procedures to take place in 2003 and 2004.

Soil and plant nutrient levels will be monitored for the life of the experiment. Likewise, vegetative growth and vine water status will be monitored each year. Fruit collection and analysis will start in year three and continue for the life of the project. Root sampling and trench observations will begin after the vineyard has been well established in years 6-10.

Present Outlook and Estimated Success in Accomplishing Objectives:
The Cornell Vineyard Laboratory in Fredonia is a well equip facility for conducting viticulture research. The project leader and laboratory staff have extensive experience with vineyard field research accompanied with basic juice quality analysis. This proposed wine grape project is complimentary to a Concord nutrition and juice quality project already being conducted at the Cornell Vineyard Lab. In the Concord project, we have successfully established and maintained soil pH levels of 4.5, 5.5, 6.5, and 7.5. We have also successfully recorded growth, productivity, and nutritional differences in that project. In cooperation with Dr. Peter Cousins, USDA rootstock breeder, and Dr. Bruce Reich, Cornell grape breeder, the Cornell Vineyard lab staff has experience with planting and maintaining both rootstock and scion variety trials. Therefore, we estimate a high level of success in achieving the desired treatments, collecting the necessary data, and interpreting the project results.

Although the Cornell Vineyard Lab is well equip for basic juice analysis, it is not well equip for fermentation and wine evaluation, the final logical step in a project of this type. The proposed project will focus on vineyard nutrition and juice quality. If wine analysis becomes an extension of this experiment through the cooperation with the Cornell enology program or a commercial winery, that portion of the experiment will be submitted as a separate project proposal.