Playing The Citrus Rootstock Market Has Risks And Rewards
October 24, 2014 
Photo courtesy of Phillip Rucks
A previous edition of “Citrus Nursery Source” announced the release of the first four experimental UF/IFAS citrus rootstocks. The list included UFR 2, UFR 3, UFR 4, and UFR 16 [pictured]. It was explained these citrus rootstocks were selected and released on the basis of their positive reaction to HLB in multiple experimental field trials under severe HLB disease pressure. Scion trees grafted onto these rootstocks showed a reduced frequency of infection and reduced disease symptoms once infected, when compared to other commercial diploid rootstocks. As is true with all experimental material, the disclaimers are critically important. Nurseries and growers were reminded that long-term performance of trees on these rootstock selections is unknown, and yield and fruit quality data is quite limited. Furthermore, trees on these new rootstocks still require thorough psyllid control, and have performed best under experimental production systems that feature constant nutrition.
Florida Foundation Seed Producers Inc. has expanded the list to include: UFR-1, UFR-2, UFR-3, UFR-4, UFR-5, UFR-6, UFR-15, UFR-16, and UFR-17. A current roster of nurseries licensed to produce these nine rootstocks can be found at ffsp.net.
Though each nursery is managing its stock differently, they are afforded the opportunity to produce liners for grafting with commercial varieties as well as establish seed-source trees. Eighteen nurseries are currently listed on the site, including commercial nurseries and nurseries producing trees exclusively for private use (company nursery).
I contacted some of the licensed nurseries to gauge grower reaction to this opportunity and to get an update on the status of production. Bear in mind the following points were gathered from a series of informal interviews and is not a comprehensive or conclusive analysis:
- Despite the experimental status of this material, some of nurseries took the opportunity to establish seed source trees. They realize and accept the inherent risk of investing in unproven rootstocks, but want to be in a position to produce liners, should one of more of these prove successful in private and public trials.
- Most of the nurseries interviewed planted the seed for liners. At presstime, the liners ranged in size from three inches to six inches tall. Quantity of liners varies from nursery to nursery, but most have only 400 to 700 liners — as germination rates were quite variable. These liners will be available for grower orders. Interested growers can lock them up now.
- A couple of the nurseries have growers lined up to plant trees produced from these liners. In these cases, the nursery is in regular communication with its customers and is promoting the opportunity. Nurseries tend to know who their more progressive growers are and they are promoting the opportunity in their direction.
- The more typical response was: “Growers are not asking for them.” Liners from these rootstocks are not sold and remain available. Nurseries feel most growers still don’t know these liners exist. In the vast majority of cases, as one would expect, these liners will be budded with round oranges. If a grower wants to try these rootstocks on something other than round orange, this is the time to contact their nursery of choice and arrange to have trees grafted with their variety of choice.
- Due to the relatively small volume of trees from the initial seed distribution, some of the nurseries are not promoting the experimental liners — as they don’t want customer demand to exceed supply. Nurseries don’t like to turn away business. They assume that they will be able to drum up enough growers to plant the trees once they are ready.
A couple things have happened to cause growers to press the “pause button” in regard to working with experimental rootstocks:
- There is knowledge that larger scale trials will take place with these liners, and also later with USDA experimental stocks. Some growers would rather wait on more formal results rather than invest time and resources on a small private trial.
- Growers talk to growers. This is a word-of-mouth business. Once the word got out that better rootstock candidates may be coming — that may be better than these — it fueled more doubt and hesitancy. Why plant these if better stocks will be out before these trees are even in production?
- Growers are reporting better results from their nutritional programs, soil pH adjustments, and psyllid control. These growers are going to stick with their current rootstocks until more definitive information becomes available. “I want to make what I know works better.”
- Longer term, most nurseries recognize that if any of these new rootstocks prove viable, it will take years to establish sufficient seed sources to meet commercial demand. It will require tissue culture (TC) and rooted cutting production. Several TC facilities are involved in ramping up their capability of producing rootstock liners.
One such facility, Phillip Rucks Citrus Nursery, has some liners of the new UF rootstocks ready now and expects to have several hundred thousand liners ready for its customers by Spring 2015. Rucks is producing liners from rooted cutting and TC.
- It’s not surprising that we heard a range of opinions on this topic. However, there were some take away messages that may prove helpful to nurseries and growers:
- Nurseries that promote are generating more interest. Don’t assume that growers are getting this information and will beat a path to your door. We have seen this with new scion varieties. Putting trees in the budwood house and waiting for orders doesn’t produce results. Talk to your growers. Actively seek information and share it.
- Large trials are absolutely necessary in this process. However, our chances of success are improved immeasurably by having more growers involved. Florida is blessed with highly skilled scientists and a committed and effective CRDF. Nevertheless, many innovations originate at the grower level. The more growers try these rootstocks the more the industry will benefit. This is a collective effort.
- Most of the liners produced from the first batch of seed are uncommitted. Growers — this is your opportunity. Yes, more and potentially better material will be coming. This is true for scions as well — but we can’t stop innovating and improving. This is an incremental process.
- Round orange growers would be well served to reserve their trees now as orange trees will be in higher demand — once the trees are ready. Growers looking for other varieties on these particular rootstocks will be sorely disappointed unless they make arrangements in advance.
- USDA-ARS has entered a large number of rootstock candidates into the DPI cleanup program. The official release of five USDA stocks (US 1279, US 1281, US 1282, US 1283 and US 1284) was announced last month. Source plant material was provided to the Bureau of Citrus Budwood Registration and will be distributed according to FDACS regulations. Watch for more information on these.
Make It A Date*
Growers, processors, packers, marketers, and more are welcome to attend the upcoming UF/IFAS, NVDMC Variety Displays.
Nov. 6: CREC, Lake Alfred
Dec. 11: CREC, Lake Alfred
Jan. 15, 2015: IRREC, Ft. Pierce
Feb. 17, 2015: CREC, Lake Alfred
* All events start at 10:00 a.m.
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