Most wine grape vines are grafted onto rootstock of another species. How does this practice increase grape yields?

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Quizplus · Accepted Answer

Grafting wine grape vines onto rootstock of another species can increase grape yields for multiple reasons. A hardy and disease-resistant rootstock can replace a weak rootstock and provide better support for the vine. A high-producing vine stock can also replace a low-producing vine stock, leading to increased yields. Additionally, vintners can select for pest resistance without sacrificing grape quality by using different rootstocks. Therefore, all of the above options are valid reasons for why grafting can increase grape yields.

Most Wine Grape Vines Are Grafted onto Rootstock of Another