In Search of the Holy Grail

After years of growing plants, any grower worth his salt is always looking for ways to tweak a little more production from his farm.

In 2002 as part of our ongoing research efforts developing sustainable nursery practices, we started to trial a new product that was new to the agricultural industry that promised accelerated growth, and an increased resistance to disease and insects of a variety of agricultural row crops. The new product was Messenger. Messenger contains harpin protein that induces plants to turn on its natural defense systems. Since that time it has been discovered but not well documented that other non pathogenic microbes can elicit the same responses when colonization occurs over the entire plant

The first of these natural defense systems is called Hypersensitive Reaction, which induces the few cells that are in direct contact with Erwinia amylovora (the fire blight pathogen) to collapse, effectively halting the spread of the infection.

The second plant response is called Systemic Acquired Resistance (SAR). When plants are sprayed with harpin protein derived from Erwinia, SAR provides protection against a broad range of pathogens much like a vaccination protects people from the flue.

The third response in an increase in photosynthesis, resulting in faster maturing crops with higher nutritional levels as measured by brix. Studies have shown that when a plant has a high Brix index reading they are not appetizing to insects. Brix is the measurement in percent of soluble carbohydrates (sugars) in the cytoplasm or plant sap.

The fourth attribute related to harpin is insect resistance. Insects will generally attack weaker plants because the plant sap is lower in carbohydrates than healthy plants. Plants that are feed too much urea, or ammonium nitrogen will grow soft lush foliage that is more susceptible to insect attack. Protease inhibitors will be discussed later.

We’ve used Messenger since 2002 as part of our sustainable integrated pest management program when we witnessed a surprising growth response from Fuchsia Garden Mister Bonistat. This plants dark maroon leaves blocks sunlight from the chlorophyll in the middle lamella. They normally grow extremely slowly in the dark months of our northwest winters. Since then we have seen a strong growth response in a variety of crops. Messenger has become part of our production practices for everything that we produce.

At least two other materials with different modes of action give similar responses in plants. Recent studies indicate that many plants grown in a soil-less substrate benefit from the addition of silicon in the nutritional program. Intrepid Coco-Coir® supplies silicon when the high level of biological activity present in the soil weathers the Olivine. Silicon is an essential nutrient for some plants, most notably cucurbits. Recent studies indicate that silicon increases the brix index of hothouse grown vegetables. Brix is the measurement in percent of total dissolved solids or carbohydrates in the cytoplasm. In the case of vegetables, higher brix measurements are used to indicate when a vegetable has reached peak nutritional value for harvesting. Plants in the Cucumber family require silicon in their diet to facilitate suberization or stiffening of the cell walls. Cucumbers growing without adequate supplies of silicon are much more susceptible to becoming infected with powdery mildew and other diseases.

Plants can also use these defense mechanisms to protect themselves from invading pests. Thorns on a rose evolved to keep it from being eaten by animals. New research indicates that plants, when given the right stimuli activate what is called the systemic wound response. When an insect starts to feed on one part of a plant, a chemical peptide signal called systemin travel throughout the entire plant, stimulating it to produce protease inhibitors. When an insect starts to feed on these plants, the chemical inhibitor blocks the digestive enzymes (proteases) in its gut, causing digestive upset and it stops feeding.

Several years ago, while researching which insecticides to use in our integrated pest management program, I was drawn to a class of chemicals called Neonicotinoides or synthetic nicotine modeled after the natural botanical insecticide nicotine. When I was in high school, I worked on a mink ranch in Deming WA. We diluted nicotine sulfate ten to one in isopropyl alcohol to make a particularly lethal preparation. When it came time to harvest the pelts, the owner would inject one cubic centimeter of this into the mink’s chest cavity. My job was to quickly catch and hold the mink for the injection. The nicotine proved so effective that few animals were still alive two seconds after I set them back in the cage and started to catch the next mink. I never took up smoking after that experience and thirty years later, it helped me make the decision to choose nicotine as one of the few chemicals we use for insect control. My decision was easy because it is a systemic with long residual activity, no cross-resistance with other classes of insecticides and is more selectively toxic to insects than mammals.

Resent research indicates that Neonicotinoides are also responsible for turning on a plants natural defense system. I won’t go into any more detail other than to say that I have had very good results. The integrated systems I have developed produce exceptional quality year after year. When Messenger, silicon, and neonicotinoides are used in a rotating program, plants can actually protect themselves without the use of highly toxic chemicals and grow healthy in the most natural way possible.

This research is a result of our ongoing quest to develop the best production practices for producing outstanding quality that goes beyond what can be seen. We continue to study the latest products from agriculture and apply techniques that result in optimum quality and the healthiest possible plant so that the end consumer in assured a successful and enjoyable gardening experience. An experience that motivates them to return to your nursery and buy more of our plants.