Grape growing throughout the world is a challenging endeavor. Grapevines, being a perennial plant, are not replanted from year to year and this has implications for the farmer. Annual crop rotation is a good pest management tool. Those bugs and diseases that attack last year’s crop might not thrive as well with this year’s planting. You keep shifting the ground beneath the critters and they don’t go forth so easily and multiply.
Pest management is one challenge to growing perennial grapevines; the weather, specifically the winter (which we in the Finger Lakes have in spades), is another. Grapevines have to ride out the winter as best they can. Generally the varieties planted can withstand fairly harsh winter conditions, but each variety has a different level of cold tolerance. While it is hard to kill a grapevine, it is easy to make them unproductive. Cold weather, specifically sub-zero weather, can damage grape buds, and the shoots, leaves and most importantly the fruit emerge from these buds.
One of the tasks we perform in the winter is pruning. Most of the growth from the previous year is pruned away, leaving (hopefully) fruitful buds that produce a crop that is small enough to ripen for high quality wine and large enough to be economically viable. Before we prune though, we assess the vineyard for winter injury, specifically we test bud mortality. (more…)