This set of management recommendations may seem daunting at first. Some of you may not have enough resources (time and/or money) to fully implement the whole program on all of your susceptible acreage. It is often asked how best to deploy limited resources against this disease in heavily infected orchards. Not an easy task since everyone has a different situation and not implementing all of the management tactics is risky.
Given limited resources you have several choices:
- You could pretend the disease was not in your orchard and do nothing;
- You could do a portion of the controls on all of your acreage;
- You could do all of the controls on a portion of your acreage.
The practice of doing nothing will never be recommended. The data are clear, the disease will spread quickly and significantly reduce yields.
Most growers try a little something on most of their acreage. We have very little data with which to guide you in this area. We know that practices such as only cultural controls in the absence of chemical controls will not control EFB. We also know that the single fungicide spray per year approach will not work either. In any one year, a single spray at bud break has a 60% probability of achieving EFB control.
However, over multiple years, there will be a 100% failure of control.
So how about implementing all of the control recommendations on a portion of your acreage? Ok, but what portion? In general, many growers may be overly focused on the diseased part of their orchard.
Growers should focus their energy and resources on the healthy part of the orchard each year. All of the disease management tactics are geared toward protecting or reducing the EFB risk of healthy trees. The act of removing cankered wood from an infected tree is as much an act of reducing the spore load in your orchard as it is to eradicate EFB from the tree. Time spent scouting for EFB is best done in the healthy orchard since that one canker can become hundreds if not found early. Although scouting for cankers in the infected orchard is easier, you already know it is there! The fungicides can only protect healthy shoots and trees. They can not remove cankers from infected trees.
So the healthy portion is protected but what do you do with the diseased portion of the orchard? This will depend on what resources you have left. How many cuts can you afford ($) per tree? One? Two? Not much of a tree is left but it may be the right decision. What about fungicides? Some of you get a better price on copper products but realize it is not as effective as Bravo. You might consider using Bravo on the healthy part of the orchard and copper products on the diseased portion.
The first choice would be to implement the full set of recommendations on all of your acreage. We know that growers who have done this for many years have been able to maintain yields as if there were no disease. Doing nothing is unacceptable especially from an area perspective as it increases the whole industry's risk to EFB. Orchard inputs increase when managing EFB. It is difficult to justify these inputs especially when nut prices are low. Smaller acreage may be necessary to adequately control EFB given the same amount of resources.
Everyone knows the Hollywood mythology that werewolves can only be killed by a silver bullet. We sometimes extend the analogy to plant diseases such as EFB where we hope a single application of something (the silver bullet) will completely control the disease. Like the werewolf, such hopes are probably mythical. Management of EFB will require hard decisions and a lot more work. It is often said that EFB takes the FUN out of filbert farming.
This does not mean that the future is not bright. Indeed, new chemical registrations along with new resistant cultivars are available. There is good reason to believe that the next generation will still be growing hazelnuts, profitably, despite the presence EFB.
