September 5, 2018

3 Min Read

By John Wood, Certis USA Regional Manager

Harvest will soon be complete as pest management practices quickly turn toward fall protocols.

Around this time of year is the period we call root flush. The trees are generating essential new roots that will be used to store carbohydrates over the winter to allow for a stronger tree at bud emergence in the spring. These roots need to be protected, so there are two practices I recommend at this time of year. One, make a biofungicide application with Double Nickel LC through chemigation and second, about 30-days later, follow up with an application of MeloCon nematicide.

Recommendations: Double Nickel LC biofungicide first, followed by MeloCon WG biological nematicide

These important new tree roots warrant strong protection as they face disease and pest pressures. Applying Double Nickel LC biofungicide through chemigation employs five modes of action to provide effective root protection at low rates. The active ingredient of Double Nickel LC is a naturally occurring strain of a beneficial bacterium that colonizes and protects those young roots. In fact, it uses the root exudate, or the excretion on the root flush tip, as its food source. Double Nickle LC continues this colonization as long as the roots are in the flush zone protecting against soil-borne diseases and providing a physical barrier against nematode attacks.

As the roots grow, they attract nematodes to the root zone. Once nematodes infect tree roots, they live within the root tissues and the water film that surrounds roots where they feed on tree roots, stealthily waiting to steal the all-important carbohydrates the roots must store over the winter. Double Nickel LC provides nematistatic protection allowed under a FIFRA Section 2(ee) recommendation for the suppression of root knot (Meloidogyne spp.), cyst (Globodera spp.), lesion (Pratylenchus spp.), ring (Mesocriconema spp.) and spiral (Helicotylenchus spp.) nematodes. Suppression of nematodes occurs when Double Nickel LC is applied as part of a soil pest and disease management program.

To supplement the Double Nickel LC application, apply MeloCon WG biological nematicide through chemigation to distribute it in water 30 days after the Double Nickel LC application. MeloCon is a parasitic fungus that attacks all stages of common plant-parasitic nematodes, especially against eggs and infectious juveniles. Nematodes use water as a transportation source. Distributing MeloCon via chemigation gives it more opportunity to come into contact with and infect nematodes.

Remember that these must be separate applications. It is important not to combine Double Nickel LC and MeloCon as a tank mix, because MeloCon is a live fungus. Double Nickel LC is anti-fungal. This is why it is so important to wait 30 days between applications.

Root flush happens on nut trees twice a year: bloom/pre-bloom and harvest/post-harvest. Though labels indicate Double Nickel LC and MeloCon can be applied anytime of the year, the most cost-effective and efficacious times to use them are during these two periods. Remember, Double Nickel LC and MeloCon have 4-hour REIs, zero-day PHIs and both are residue exempt.

For more information about root flush and the use of biopesticides, you can contact your local Extension agent. The UC-IPM website at ipm.uncanr.edu has sound information available and your PCA and certisusa.com have additional references specific to the biopesticides.

Subscribe to receive top agriculture news
Be informed daily with these free e-newsletters

You May Also Like