Growth Products, Ltd: Agriculture


Dr. Christopher Becker

BAAR Scientific, LLC

6374 Route 89

Romulus, NY, 14541

Introduction: New York is the second biggest apple producing state in the country. Fire blight (Erwinia amylovora) is a difficult bacterial disease for the apple growers. It is unpredictable, control measures are limited and application timing is critical. Given optimal conditions it can wipe out an entire orchard in a single growing season. The bacterium is dormant over winter and over-winters in living tissue at the margins of cankers. The disease becomes active again in the spring when temperatures get above 18°C (64°F). Rain, heavy dews, and high humidity favor bacterium growth. The most popular varieties (Gala, Honey Crisp, Red Delicious, Granny Smith, Fuji, Jonathan) are also the most susceptible to Fire blight, a disease that can spell disaster for apple growers. As with Apple scab or black spot caused by the fungus Venturia inaequalis, it also winters in debris.

Objective: Determine the efficacy of Companion® Biological fungicide as a standalone treatment or in combination treatment with Growth Products TKO phosphite 0-29-26 for Fire blight and Apple scab as compared to Regulaid®* and a 17% Streptomycin.

Method: Potted apple trees (Cultivar Idared) were used for this study that had 5 to 12 blossom clusters per tree; 2 year old trees from Waffler Nursery, Wolcott, NY. Eight individual potted trees served as eight individual replicates per treatment. Trees were treated during early, mid, and late bloom on May 27, May 31, and June 3. All treated trees were inoculated with a 1 x 10 7 solution of Erwinia amylovora on June 4, 2017.

Using a CO2 Backpack sprayer calibrated to deliver 100 gallons per acre, the trees were sprayed to first drip with a “dilute” solution of products. Trees were sprayed in late afternoon, each day, where drying conditions were very good. Inoculation on June 4 was conducted at approximately 5 pm, followed by overhead misting of the trees for 15 minutes. An additional 0.19 inches of rainfall was recorded overnight and trees remained wet until about 9 am the next morning. For the inoculation at bloom, a 1 x 107 suspension was atomized onto all blossoms.

Fire blight data was collected from all the shoots that had blossoms on each tree. Within 10 days there was the visual wilting of the flower clusters, and the first data was collected on June 18. Data was collected by estimating the resultant area of the flower cluster that expressed symptoms of Fire blight. Data represent severity data as the area was estimated per tree and the average across the 8 trees per treatments. A second set of data was collected on July 10, which was approximately 5 weeks after treatment. Additional applications of treatments were applied on June 10, June 24, and July 3. These applications were made, in order for evaluations of treatments against Apple scab.

Results & Summary


The trees where no treatments were applied had an average of over 18, and 58 % of the shoot area with Fire blight remained June 18, and July 10, respectively. Streptomycin treated blossoms resulted in 0.47 and 8.13% of the shoot area with Fire blight. On June 18 (2 weeks after inoculation) the treatment with Companion alone had 15, 76 and 34.84% of the shoot area with Fire blight. However the amount of Fire blight actually increased when Regulaid was added to Companion®. Companion® plus TKO 0-29-26 resulted in increased management of Fire blight, compared to Companion alone at 64 oz. /acre.

This trial was a severe evaluation of the treatments against Fire blight; because the weather at the site had 6.32 inches of rain in May, 3.37 inches in June, and 5.51 in July. Temperatures while slightly below normal, were in the optimal range for the development of Fire blight. In this study, it appeared that Companion alone or especially with the addition of TKO 0-26-29 provided reasonable reduction in Fire blight. Dr. Christopher Becker states “I suspect that in an orchard situation, the reduction would have been greater”.

apple study

Apple Scab

Apple leaves were evaluated for the percent area with Apple scab lesions on July 20, 2017. All the treatments that contained Companion® had severity of Apple scab that was significantly less than the non-treated controls. This trial showed that Streptomycin and the TKO 0-29-26 had essentially no efficacy against Apple scab. Streptomycin has no efficacy against fungi and would not be expected to have any effect against Apple scab. That the TKO 0-29-26 had limited efficacy against Apple scab is consistent with an evaluation of previously published reports. None of the treatment had what might be considered commercial control; however, because the trial was not started until the end of May, there were significant infection events for Apple scab. What is great to see, is that the addition of Regulaid slightly reduced the severity of Apple scab, compared to Companion alone. Plus, the addition of TKO 0-29-26 provided significant improvement in the management of Apple scab, compared to Companion® alone. An explanation for improved management of Apple scab for TKO 0-29-26 over Regulaid®, probably surrounds the ability for Phosphorous Acid fungicide products to be very systemic within plants.

No phytotoxicity was noted on the apple trees in this study.

apple study

TKO Phosphite is a registered trademark of Growth Products, Ltd.
Companion Biological Fungicide is a registered trademark of Growth Products, ltd.
Regulaid is a registered trademark of KALO, Inc.