Seed Trace Content of Fiesta Grapes

The number and size of seed traces in Fiesta raisin grapes was investigated for three years in commercial plantings and rootstock trials. Generally, Fiesta grapes contained about the same count of visually noticeable traces as Thompson Seedless, regardless of rootstock and vine age. However, Fiesta traces were most often larger than those of Thompson Seedless. Exceptions involved individual Thompson Seedless vineyards which produced larger than typical traces in some years. Fiesta trace size was significantly smaller when grown on Thompson Seedless roots. They also tended to be smaller in Fiesta grafted onto mature vines as compared to grafts on young, newly established vines.