Fowler Nurseries, Inc. Bud Failure Handout

For decades, Fowler Nurseries' business policy and the Fowler family's philosophy has been and is to be upfront and honest with our growers and keep them informed, whether it be concerning varieties and rootstock selection, product availability or issues concerning the quality of our trees. So, we ask that you please take a few minutes to read this informational letter concerning Non-infectious Bud-failure (BF).

If you are producing almonds, then you are aware of the potential for BF to be expressed in many almond varieties, most commonly in Carmel and Nonpareil. Fowler Nurseries has been fortunate for the past 25 years to have used a Nonpareil source with extremely low BF potential. This source has been referred to as ‘Nico W'. You may have noticed this source designation on our tree bundle labels. This source has been our old reliable workhorse, which produced little to no BF until recently. We have received grower reports of some BF in recent years, and this month we were alerted to the presence of 1.1% BF in a fifth leaf orchard. This situation is a primary concern for us and is prompting this notice informing you about our BF status and our efforts to provide the best nursery stock possible. You have put your confidence in our selection of Nonpareil sources; and we do not take this confidence lightly. Let us tell you what we have been doing to keep the confidence you have shown in us.

Recognizing our ‘Nico W' source may not maintain its low BF potential forever, we established Nonpareil budwood trees from 7 new Nonpareil sources with ‘reported' low BF incidence. This was done about 10 years ago, long before we received any report of BF in ‘Nico W'. One of the more interesting sources is called ‘3-8-2-70', which you may have noticed on our bundle labels recently. However, ‘reported' low BF is not an adequate standard to earn our confidence. So, that is why we initiated BF progeny trials to methodically assess each individual new budwood tree for BF potential. The oldest of these trials is in its 6 th leaf. All the trials are being conducted in the southern San Joaquin Valley , where conditions are the most conducive to the expression of BF.

In case you are not familiar with progeny trials, they are established by taking budwood from each scaffold of an individual budwood tree (mother tree), propagating ‘progeny' trees from this budwood and planting the progeny trees in a commercial style orchard with detailed mapping. The progeny trees are surveyed annually for the expression of BF. The detailed mapping enables tracing progeny trees back to the mother tree, in the event BF is expressed. Our process of establishing new sources started 10 years ago and will continue for at least another 4 years. The process of establishing new sources would be simple if the budwood trees expressed BF, but they do not. And if they did, we certainly would not cut from such a tree.

No Nonpareil source can be considered BF free. Every source has potential for BF expression. The challenge is to find a source with the lowest potential for BF expression. As mentioned above, we are utilizing progeny trials to determine the BF potential for each individual source budwood tree; and our new sources are in various stages of progeny trials. Although some of these trials are in the 6 th leaf and are showing no signs of BF, we are continuing to use our ‘Nico W' source until our confidence is firmly established in the new sources. In our opinion, it is not prudent to jump into new sources without the confidence that the new sources are better than ‘Nico W'. There is a risk of BF with using ‘Nico W', and likewise a risk in using an unproven source. We will continue to put a source designation on our bundle labels, as well as on invoices, since this is so important to you and to us. Keeping sources mapped in your orchard can help identify a budwood tree or source that has degraded toward producing trees with BF. Yes, this implies that a good source can change from low BF potential to higher BF potential.

The BF potential for a given source is not static. BF potential is dynamic, changing with stresses, weather, successive seasons of growth and re-propagations of budwood trees. Our ‘Nico W' source is an example of the dynamic nature of BF having changed over the 25 years of use. The dynamic forces, that affected ‘Nico W', are also affecting other sources. This is why long-term progeny trials are so important. While our progeny trials are located in an area conducive to BF expression, we have our new budwood trees located in the vicinity of Nicolaus, 26 miles north of Sacramento , because of its relatively cool spring and summer weather. Additionally, our budwood trees are and have always been maintained in the manner recommended by the late Dr. Dale Kester, UC Davis, to slow the progression of BF. The dynamic factors are also present in your orchard. Of the factors mentioned, stress is the only factor you have any control over. Stressful conditions in your orchard can bring about the expression of BF. Examples of some stresses are heavy cropping, excessive irrigation, and dry soil conditions.

No discussion of BF can leave out comments on Carmel . We have been offering two sources of Carmel : Carmel #1 and Carmel BRO. Carmel #1 (aka FPS#1) is the source that was recommended by Dr. Kester based on his progeny trials. Very limited amounts of this source were made available to nurseries for propagating their own budwood trees. This source, from our budwood trees, is expressing 6% BF in a 5 th leaf orchard. We have heard stories (unverified) that this source from other nurseries is expressing as early as the second leaf. Demand for this source was created by the University recommendation; and this demand did not permit the completion of progeny trials on individual nursery budwood trees. As with Nonpareil, we recognized the need for establishing alternative sources for Carmel prior to receiving reports of BF from existing sources. We initiated a new source called ‘Carmel BRO' in 1993. We were able to perform progeny trials on our ‘Carmel BRO' budwood trees. And the progeny trees did not express BF until the 9 th leaf, when less than 1% of the trees expressed. On the basis of our progeny trial and grower experience we are recommending the use of Carmel BRO at this time. As with Nonpareil, on our invoices and bundle labels, you will find the Carmel source stated for the trees you receive.

As you can see, we have not been idle when it comes to providing Nonpareil and Carmel nursery stock with low bud failure potential. Our efforts are exceptional in the nursery industry because we recognize the trust you place in your nursery stock provider. The Fowler Nurseries commitment to quality nursery stock has been a hallmark for the past 93 years and will continue into the increasingly complex future. This letter has information and potentially new concepts that may generate questions. We encourage you to contact us to discuss your questions, concerns and appropriate responses to the presence of BF in your orchard. A copy of an article by Joe Connell, UCCE Butte County , is attached to this letter to serve as a guide for your personal decisions as you assess the impact of this regrettable turn of events.