Bye Bye 101-14 MGT

One of the casualties of our replanting was this rootstock that lost it's grafted scion which we let grow. The reasons why almost all grapevine growers have to choose a rootstock is a complicated and captivating story about a root louse called phylloxera that I'll put off for a future blog, but if you are interested, a really good book to read is called The Botanist and the Vintner by Christy Campbell.
Before choosing 101-14 MGT to be our rootstock, we did a lot of research on what our area grape growers use for rootstock, beginning with reading Grapevine Cultivation in Connecticut, the 2007 Bulletin written by William Nail (Assistant Scientist), from the Connecticut Agriculture and Experiment Station. The recommendation at that time, was 3309C. We did more research and also asked Mercier, CA about 101-14 MGT. When choosing a rootstock, the following criteria should be kept in mind:¹

• Tolerance or resistance to root parasites such as phylloxera and nematodes
• Ability to influence crop maturity
• Tolerance of adverse soil conditions such as drought, waterlogging, lime and acid or saline soils
• Ability to contribute to the management of vine vigor
• Ability to contribute to grape maturity and composition

A site that summarizes the above characteristics for a rootstock of choice is Rootstock Selection written by Larry Christiansen.
Almost all rootstock is a hybrid of three species: Vitus riparia, V. rupestris, and V. berlandieri. Our rootstock, 101-14 MGT is a hybrid of V. riparia and V. rupestris. It has high phylloxera resistance, low-medium drought tolerance, but better for wet tolerance and has a better influence on the scion vigor compared to 3309C.
Something that I learned while reading Markus Keller's book, The Science of Grapevines Anatomy and Physiology is that the rootstock varieties are dioecious which means that they can be either male or female. Examples of male rootstocks are Teleki 5C, SO4, and Riparia gloire de Montpellier. Examples of female rootstocks include Kober 5BB, 101-14 Millardet et de Grasset, and Fercal! Who knew!
References:
1. Markus Keller, The Science of Grapevines Anatomy and Physiology, 2010, Academic Press, pg. 17.