Evaluation of Seven Rootstocks Grown under Saline Condition in the San Joaquin Valley of California
Field trial, consisting of seven rootstocks, replicated in 3 times with 5 vines per experimental unit, was planted in 2015 at west side of Fresno County, and the scion variety of Pinot gris was field grafted in the spring of 2016. Data including soil/irrigation water salinity, tissue nutrients, yield components, harvest berry composition, and pruning weight were collected for the first (2017), the second (2018) and the third harvest (2019). Preliminary results from the three harvests have shown some interesting results among the rootstocks. Previously regarded salt-tolerant rootstocks for Cl, e.g., 1103P, 140Ru, Ramsey, performed as expected and our data were largely in line with previous results.
So far, rootstocks in our study had significant impact on plant nutrition, yield component and pruning weight, however, minimal effect on harvest fruit chemistry. Instead, vintage, especially irrigation water sources, played a crucial role in it. Interestingly, GRN 2 and 3 rootstocks which accumulated the most Cl, had the highest accumulative yields and pruning weight, although petiole Cl didn’t exceed the critical value. and this trial is still ongoing to collect more data to confirm the long-term impact. As for boron tolerance, GRN 3 rootstock showed the least amount of B uptake across three years. Correlation between juice Na and pH, berry size and B, have been found and it further validated the importance of rootstock selection, since rootstock might largely affect the fruit/wine chemical composition and yield.