Missouri winemakers are watching their grape vines carefully this summer.
A little stress can positively effect grape quality, but as wine experts are concerned this year’s heat and drought may be too much.
A moderate water deficit is good for grape quality, according to Anthony Peccoux. He’s a viticulture professor the University of Missouri. That’s especially true after the fruit turns red.
“Because it helps for biosynthesis of intersecting compounds ... all these compounds we call polyphenal. It’s both anthocyanin and tannin. And these compounds give the color of the wine and the characteristics and body of the wine," said Peccoux.
But he warns too little rain and too much heat can overstress the plants, and hurt its yield. He says he’s already seeing drought symptoms in some vineyards.
At River Ridge Winery in Commerce, Mo., owner Jerry Smith feels pretty good about this year’s grape crop. All of his vines are well-established and handling the conditions well.
“The only trouble that we’ve had this year, is with the season being two to three weeks earlier than what we expected, from everything budding out in the spring, it has changed the control of our midsummer pests called Japanese beetles. We’ve had to spray more often for those, but they’re under control now," said Smith.
Smith says the years 1980 and 1999 both produced the highest quality wines in Missouri. Both were years of prolonged drought.