Are you good at math? You can predict the future fruit quality of your hardy citrus seedlings with the following formula:
Fruit Quality = (Leaf Taste (0-100) x .14) + ((Cold Hardiness (°F )+ 15) x 3.33) x .52) + 21.39 ± 10
Leaf taste examples: Trifoliate Orange = 10, Benton Citrange = 50, Yuzu = 100.
This formula is based on the data collected from 48 citrus trees that have been taste tested as well as grown on our property so that their leaves could be tasted and counted. Our original idea was to incorporate leaf type into the prediction model (percentage of leaves that were unifoliate or bifoliate), since this would be a normal, practical test someone might conduct. However, the current data showed there was no meaningful correlation between leaf type and fruit quality when controlling for true citrus vs. Citroncirus (Citrus x Poncirus).
Please note that we are limited by our sample size, as well as the numerous and inconsistent sources for the fruit we tested, and we cannot guarantee the same effects across a larger or more controlled sample. However, the link between cold hardiness and reduced fruit quality is undeniable! Unfortunately, cold hardy citrus breeding will always be limited by this fact, but there is promise in the meaningful overlap that exists between fruit quality and hardiness ratings.
There is a very strong correlation between (lack of) cold hardiness and fruit quality.
There is a medium correlation between leaf taste and fruit quality. We attribute this to the fact that there are measurements contributing to fruit quality that are probably not linked to leaf taste (ie. fruit size, seed count, peelability).