Two weeks ago, I removed a failing vine and replaced it with one of the back-up vines I kept in planters just for this purpose. It was a great opportunity to spend some time with my seven year-old daughter.
We selected a robust looking backup vine, gently removed it from its planter and placed it in a bucket of water and made our way uphill.
Before we did anything, we collected a few leaves from the expired plant and a few from its neighbors. I wanted to compare the leaves later to see if Jeff Miller’s hypothesis, was correct.
With the leaves tucked into envelopes, we slowly and gently dug up poor Kenny and put in the replacement vine.
As returning readers might remember, these vines are clone 7 Aglianico grafted onto 1103p rootstock. This particular rootstock is a cross of two American Vitis species: V. berlandieri and V. rupestris. It combines the high vigor, moderate nematode (unsegmented roundworm) resistance and moderate tolerance of wet clay soils of rupestris with berlandieri’s tolerance of arid soils and hillsides (which, in turn, is not a strength of rupestris). It is also supposed to do best in loam or lime soils.
If the canopy growth of this vine was due to rootstock growth, then the leaves should resemble their parents morphologically. It seems to me that the leaves from my failed vine resemble berlandieri more than they do rupestris. One might also be equally justified in believing that they display characteristics of both. It would not be unexpected for a crossed plant to exhibit a mix of traits of both its parents. But some of the younger leaves on my healthy vines can resemble those on the failed plant. What gives?
I gave up trying to identify consistent similarities and differences in the overall shape of the pulled vine’s leaves (as well as the shapes and proportions of their lobes and sinuses) and those of the healthy vines. I found some comfort in reading a post by THE original wine blogger, Jack Keller, in which he suggests that leaf shape varies with maturity.
When we finally pulled out the dead vine, the near total lack of root development was striking. This vine looked essentially like it did when it arrived. This brought another idea to mind.
Vines accumulate starches and other nutrients before going dormant. They pull many of these substances in from the leaves and shoots and store them over winter. These stores are used to start new buds and shoots in the spring. As the vine does this, its leaves turn color and eventually drop. That is why pruning takes place after a vine’s leaves have been shed.
Given the fact that my neophyte’s examination of the failed vine’s leaves yielded no definitive conclusions and that the root system essentially failed to develop, could the stunted canopy development in this vine be, in fact, Aglianico? Could it be that the growth this vine saw was fueled only by the stored reserves in the scion? And could it be that it was the rootstock and not the scion that failed, resulting in failure of the vine once its nutrient stores ran out?
I welcome thoughts, comments and discussion.
Granted, my appraisal of the dead vine’s leaves could be completely wrong. Ultimately, there is a new vine in its place. It is doing well two weeks after having been put in. It should do well.
However, there were some other issues I discovered and will discuss them next time.