Page 44 - Grapevine March-April 2020

Around The Vineyard

of the relationship between soil, water and plants, its water into developing grape clusters, instead
Dr. Zelinski helps vineyard growers reach their pro- of growing more leaves. In the drier regions of the
duction goals with one-on-one consulting, which United States, vineyard irrigation is indispensable,
includes deploying a combination of traditional and drip irrigation is the method of choice.
methods and cutting-edge technology. Since most
of his clients operate vineyards in a region where Some vineyards are fortunate enough to be in a
water supply is at a premium, there is not enough climate where water stress is rare. Such is the case
water flow for sprinklers, not to mention a topogra- for Black Star Farms, whose vineyards are located
phy that defeats any chance for successful furrows. in northern Michigan, near the resort community of
Hence, drip irrigation is the choice. Traverse City.

Dr. Zelinksi points to monitoring as an important “We really only irrigate in the early stages of a
element of any vineyard irrigation system. “Most vineyard’s life, when young plants need plenty of
have or will have soil moisture monitoring stations. water to get a healthy start,” says Lee Lutes, wine-
They also have weather stations, and, as needed, maker and managing partner at Black Star Farms.
we use a leaf porometer.” “We often see a little drought in early to mid-sum-
mer, and with our well-drained soils, it’s the time
Therein lies part of the science—the “E.T.” fac- those young vines need the help. We only use drip
tor—so critical to vineyard irrigation. A porometer irrigation as a means of monitoring how much is
measures water stress in a grapevine, specifically, dispensed to each plant and to specifically focus it.
its leaves. The device gauges how much water the After year three, the system is typically never used
grapevine leaf is taking in through the small pores again. We are fortunate that we get more than
on its surface. If there is too much water evap- enough water during the spring and fall, so vines in
oration from the leaves, they will wither. When our region rarely show signs of water stress.”
leaves on a grapevine show signs of stress, the
rate of evaporation and the ability for the plant to On the opposite end of the 45th parallel is
cool itself drops. The leaf porometer allows grape Washington’s Two Mountain Winery, a name
growers and their consultants to keep tabs on this inspired by the views of Mount Adams and Mount
process. Rainier, seen from one of the winery’s multiple
vineyards in Yakima Valley. Brothers Matthew and
Another crucial factor in vineyard irrigation, Dr. Patrick Rawn own and operate the winery. Patrick
Zelinski says, is monitoring vineyard soil conditions. Rawn is the general manager and spearheads vine-
“Soil moisture monitoring is important because it yard operations. He says Two Mountain Winery has
gives an objective measure of how much water is in used a mix of irrigation methods.
the soil at different depths,” he says. “Additionally,
with the correct soil probes, the strength with “We use drip on the vast majority of our acreage.
which the soil is holding onto the water can be We have a few blocks with micro-sprinklers that
determined. This indicates how hard the vines need were installed to allow for planted cover crops
to work to extract water from the soil. Monitoring to help achieve crop objectives. In those blocks,
at different depths also indicates whether or not we also have drip systems to irrigate the vines,”
the soil is being over-watered or under-watered.” says Rawn. “We have had mixed success with
micro-sprinkler systems. The early ones installed
While the application of extra water in the cultiva- were poorly designed and did not achieve the
tion of wine grapes takes on more than one form, goals. The newer ones achieve the goals but at the
the goal of controlling water stress is universal. To cost of more water usage. We have found drip to
strike this balance, the grapevine receives adequate be the most efficient as well as most effective in
water during the budding and flowering stages. reaching our quality objectives. Choices are based
Irrigation is then scaled back during the ripening on site characteristics, water source and intention
stage, thus allowing the vine to channel most of of the block when planted.”

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