The objective of this project is to evaluate rootstocks for winegrape performance in a wide range of coastal, foothill and central valley production areas, and in sites which are infested with phylloxera, nematodes or both, or which have the potential for such infestations. In 1992-93, 9 rootstock trials were harvested. A total of 16 trials are mature enough for harvest in 1993-94. The VR hybrid rootstock trials in Alexander Valley and San Jose, indicate that the rootstock VR 039-16 is the best rootstock for sites infested with fanleaf degeneration complex. Improved vine growth and yield as well as decreased rate of fanleaf infection are seen for 039-16 in both sites. At this point there are no other rootstock recommendations which could be made for fanleaf sites. Recommendations for planting 039-16 outside of fanleaf sites cannot be made until more is known about phylloxera resistance mechanisms and the risk posed by this one-half vinifera rootstock. In other experiments, rootstocks seem to be showing site x genotype interactions. This is especially true for Teleki 5C and 110 Richter. In deep, fertile soils well supplied with water, 5C shows itself to be quite vigorous, producing about 0.8 lbs cane prunings/ft row versus 110R at less than 0.4 lbs. However, in a hillside site, 110R is one of the top-ranked rootstocks in both growth and yield. These types of site interactions mean that multiple trials will be necessary to help choose an appropriate rootstock for the wide range of coastal and northern production sites. Details of individual trials are given in the full report.
/wp-content/uploads/2017/09/AFV-Header-Logo.png 0 0 AVF /wp-content/uploads/2017/09/AFV-Header-Logo.png AVF1992-11-17 11:27:192017-11-17 11:30:10Field Evaluation of Winegrape Rootstocks