In the past three years Devon Vorderburg has shown top avocado growers in the Americas how they can turn a failing farm into a Profitable High Production Farm through lowering inputs and eliminating Insecticides and Fungicides. Devon has stated “There is always fear and chaos is always involved when growers use a reactive approach of "let’s throw a chemical on it mentality" he explained to Colombian Avocado growers. Devon is an American expert, representing Agri-Organic of Panama, on high-production sustainable agriculture who is highly respected in Colombian Agriculture and had recently spoken to farmers in Antioquia about alternative methods to control disease and insects.
In Orchards across the Americas an unseen battle plays itself out every year. Alternaría – botrytis spore lands on avocado orchards. The fungus inadvertently releases its signature protein, its natural calling card. Foliar receptors on the avocado leaves picks up this calling card and bind to the signature protein, setting off a cascade of biochemical responses. One of the responses is the formation of a flavonoid called stilbene. The function of the stilbene is to block the destructive enzyme. The Botrytis fungus releases to damage the cell walls of the fruit.
Natural defense systems
Devon explained that plants, like humans, have immune systems that respond to external cues. These external cues prompt a plethora of biochemical responses that trigger the expression of hundreds of genes. The genes stimulate the production of biochemicals called phyto-chemicals, among other things to deter or kill invading diseases and insect pests. This response takes only minutes.
He heavily emphasized to the growers that “When humans use chemical pesticides to control pests and diseases, the rich suite of biological compounds that the plant would have naturally synthesized in order to protect itself are not produced. Consequently flavor, nutritional and medicinal qualities in the plant are reduced. The beneficial phyto-chemicals are replaced by toxic man-made chemicals. When using chemicals such as synthetic pesticides on plants we are essentially restricting the full potential expression in those plants.”
During the seminar Devon talked extensively about some of the Biochemical Weapons that plants synthesize when they are systemically induced. Mr. Vorderburg has over 15 years of experience with post-secondary metabolites. He continued to explain that flavonoids are produced to deter pathogens and plants produce tannins for UV protection to deter feeding by insects and herbivores. Phytoalexins are produced with strong anti-microbial activity and accumulate around sites of infection. Phytoalexins are highly fungicidal. Jasmonates signal and stimulate the production of enzymes that inhibit insect digestion. They are also known to be fungicidal and highly unpalatable to insects.
He further emphasized on how activating the plant’s natural resistance through a process called ISR (Induced Systemic Resistance) provides an alternative to chemical use. This alternative is an effective method of achieving quality without reducing yield.
Devon cites an example of Induced Systemic Resistance in tomatoes. Fusarium wilt in tomatoes, caused by the soil-inhabiting fungus Fusarium oxysporum, often infects and causes damage to mature tomato plants. However, scientific research has shown that treating the tomato plants with AOMMA-Agro can induce systemic resistance. AOMMA-Agro is a product packed with minerals which are the co-factors, fulvic and organic acids which stimulates microbes known as plant growth-promoting rhizobacter or PGPR. AOMMA-Agro assists plants in producing substances that promote and induce systemic resistance in the tomato. When the inoculated plant is planted in soil infected with Fusarium oxysporum, the plant synthesizes biochemicals that discourage the fungus.
AOMMA-Agro produces a biochemical stimulus that can trick a plant into believing it is under attack. AOMMA-Agro, for example, can assist plants into producing cytokinins that are involved in ISR. The soil can also be inoculated with resistance-inducing microbes such as Trichoderma harzianum. Trichoderma species are hyperparasites. They produce enzymes that collapse, shrink and digest host hyphaes – the threadlike cells of fungi. Trichoderma also produce water-soluble, diffusible antibiotics as another measure to counter fungal parasites and pathogens. Recent research has shown Trichoderma can help to control the egg and larval stages of root-knot nematodes. Some farmers in Central America use Trichoderma very effectively for nematode control in Morinda Citrifolia, Mango, Bell Pepper, Rice, Potato and Tomato crops.
Compost teas are packed with a variety of resistance-inducing substances, offering another sustainable way to fight a variety of diseases. Depending on the specific recipe, compost teas have been used to combat Phytophthora, Fusarium, Botrytis, mildew, mold and scabs.
During Mr. Vorderburgs seminar, he showed growers the plots that have been using his innovated techniques for almost three years and the results are astonishing where plots have no insect or disease pressure with lush growth. These plots produced plants with very high sugars being produced in the plant sap with brix levels of 12 to 14. The soil tilth around the plots have dramatically changed. The quality of fruit and production have increased. He revealed some innovated fertility techniques during critical points when fertilization is key. Devon presented a totally unorthodox fertility approach that growers in Colombia had not previously considered after post-harvest which increased plant energy for next year’s production and resulted in higher yields and optimum fruit quality in Hass varieties.
Devon had two very interesting questions to every grower, “He asked all the growers if this makes any sense? I hear many growers say my trees are healthy other than the fungus problem etc. Devon said that is like saying my friend is healthy considering he has cancer of the liver.” Devon then asked again if anyone wanted to take their children to the local hospital to get chemotherapy to prevent cancer? The growers responded “you are crazy” Devon responded “then why are we trying to prevent diseases in your orchards that are not even present with chemical warfare?”
Devon concluded "If you will feed your plants with the right nutrition, plants have an inherant immunity to insects and diseases without a doubt.