Varieties and rootstocks are the topics of the September episode of the All In For Citrus podcast. Earlier this month, a field day was held in Jason Griffin’s grove near Lake Alfred, Florida. He is collaborating with the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) to evaluate several rootstock/scion combinations developed by UF/IFAS citrus breeders.

Griffin has focused much of the trial work on the OLL variety line, which was developed by Jude Grosser, UF/IFAS professor of plant cell genetics. Both Griffin and Grosser are podcast guests this month.

Grosser discusses his research developing the OLL varieties and why he believes they are a good fit for Florida growers. The OLL line grew out of his relationship with Orie Lee. Lee was a legend in citrus breeding circles and discovered an interesting tree in his research groves near Saint Cloud, Florida, where the original OLL cuttings were taken.

Grosser has developed several OLL varieties that are now commercially available. Combinations like OLL-8 on UFR-4 rootstock have performed well. Grosser also recommended growers consider the Orange 14 rootstock, which has shown some tolerance to both diaprepes and HLB.

Griffin discusses his grove trials and why he selected the OLL line. Tolerance to HLB, good yield and quality are among the reasons he likes the varieties. There are several rootstock/scion combinations he highlights as favorites during the podcast. One of those is OLL-20 on a mutant X639 rootstock. 

Griffin also talks about the importance of a solid production program to promote tree health and productivity. In addition to a solid fertilizer program, he is a big believer in compost and mulch to increase soil organic matter. More frequent and controlled irrigation is also an important part of his program.