Midwest Wine Grape Crop Report Update
In this first installment of a series of articles examining the effect of the drought on vines in the Midwest, Danny Wood takes a look at the impact on grapes compared to other crops and the factors that will influence grape yields and quality at the upcoming grape harvest.
Hundreds of wineries across the Midwest are struggling to cope with heat stressed vines. On Monday, the National Oceanic and Atmospheric Administration (NOAA) said the United States is experiencing its widest drought since 1956 with more than 70% of the country abnormally dry. US Drought Monitor says the severe conditions continue to expand across the Midwest with nearly two-thirds of the region now suffering the effects of the drought. Some viticulture experts and winemakers in the Midwest are expecting an impact on wine quality and a significant reduction in grape yields at the many vineyards that don’t use irrigation.
The NOAA report quoted above, referring to the corn and soybean belt that covers much of the Midwest, says, ‘crops, pastures and rangeland have deteriorated at a rate rarely seen in the last 18 years.” The drought is expected to decimate harvests of the country’s two biggest crops, but the situation is quite different for grape growers says Anthony Peccoux, Viticulture Program Leader at Missouri University’s Institute for Continental Climate Viticulture and Enology (ICCVE). Peccoux says drought does decrease the growth of vines and grape yields, ‘but compared to other crops the grape is different because the vine has deep roots, it’s a perennial plant and it’s really different to annuals, like maize or soybean, because the root systems of established vines go deep, so grapes can uptake water deep in the soil.” In the moderate drought conditions being experienced in about two-thirds of the region, grapes are not only surviving. ‘Moderate drought conditions, occurring now when the berries turn red, usually improve the quality in most cultivars,” says Peccoux.
However, one-third of the region is in severe drought — including most vineyards in Missouri and Illinois – and in an area covering about 6% of the Midwest, including South East Missouri, Southern Illinois, Western Kentucky and about a third of Indiana, US Drought Monitor classifies the conditions as even worse: extreme drought. The situation for vineyards in these areas, says Peccoux, is much more uncertain and dependent on the water capacity of soils, soil conditions and the age of the vines. ‘For young vines without irrigation it’s very difficult because they haven’t got a well-established root system. For old vines it depends on the soil conditions. If they’re planted in shallow soil the plants could start to lose canopy leaves, but if it’s deep soil I would say that severe drought conditions are not so severe for these older vines.”
Peccoux says soil conditions, even in one wine producing locality like Herman, Missouri, can vary considerably from one vineyard to the next, making it even harder to generalize about the impact of the drought across the Midwest. However, mainly as a result of the drought, he expects the grape harvest in many areas of the Midwest to be two or three weeks in advance of last year’s and yields will probably be down, but not necessarily across the board. ‘And one thing with grapes compared to other crops,” he notes, ‘It’s a unique crop, because the value of the grapes is based on quality not quantity.”
Although most vineyards in the Midwest don’t have watering systems in place, one obvious way to avoid negative impacts of the drought is to irrigate. Near Fredericktown, Missouri, an area of the state most affected by the drought, Vance Vineyard’s, Roy Paris says his ten acres of grapes – including three acres of young, two year old vines — are unaffected. The winemaker has been using his irrigation system whenever he notices heat stress in the vines, which is almost daily. He says the drought conditions could end up improving the quality of his harvest, however his grape yield will still be lower than expected due to the frost attack across the region in May when his vines lost nearly all of their primary buds. ‘Frost ate our lunch,” he says ruefully.
Viticulture expert Peccoux also says the unusual conditions at the beginning of the year are another factor that make predicting the effect of this drought on grape yields and quality difficult. The warm winter and spring meant the growth of grapes across much of the region was about three weeks in advance of last season when the frosty conditions hit in May, destroying primary buds across the Midwest. Since then, drought has set in. ‘So this year has been really unusual,” says Peccoux.
