by George Looby, DVM
The beautiful campus of Connecticut College in New London, CT was the site for a workshop presented by the Connecticut Chapter of NOFA on orchard health viewed from the organic perspective. Michael Phillips, owner/manager of Lost Nation Orchard in northern New Hampshire, conducted an all-day session divided between a traditional lecture style presentation in the morning and then an on-site visit to the orchard at Hidden Brook Garden in Ledyard, CT in the afternoon. Michael is a long time advocate of organic management and is the author of The Apple Grower. In addition to being a hands-on orchardist, he is also an author addressing the benefits of the organic way to a healthier life.
The speaker made it very clear that certain basic principals apply when setting out to establish an organic orchard and these must be determined and adopted to before other more sophisticated measures are undertaken. First the soil pH should be in the 6.3 to 6.6 range. This is done in the context of the cation balance based on the CEC number for a given soil type. The CEC number is the cation exchange capacity of the soil. Thus, the higher the number, the more cations such as calcium and magnesium can be held in the area from which the sample was taken. Increasing the organic matter in the soil will increase the CEC number, making essential nutrients more available. The very minimum level of organic matter in the soil should be 3 percent. Phosphorus and potash readings on a CEC test should be at least 200 pounds of each per acre.
In the natural sequence of things, CO2 plus photosynthesis combine to create sugars which when combined with nitrogen, lead to the creation of protein, the soluble amino acids of which are attractive to insects. Break that loop and you are onto something big. Fruiting plants belong to the biological transition zone where fungal biomass is ten times that of bacterial biomass, thus encouraging this relationship is an important goal. All trees originally developed in an environment where fungal biomass predominated so developing measures to replicate this natural sequence should do much to foster good tree health. Using products such as wood chips and aged compost favor fungal development which in turn lessens the bacterial population which in turn means less nitrate formation, less amino acids, less bacterial growth.
The hosts for the afternoon session were Bill Sokol and Anita Kozchinski who own Hidden Brook Garden located almost across the Thames River from the college in the town of Ledyard, CT. They have been certified as organic orchardists by the Baystate Organic Certifiers. The latter organization is accredited by the National Organic Program to certify organic crop, livestock and wild crop production as well as organic handlers (processors) for the northeast U.S. In addition to the orchard, Bill and Anita grow and sell vegetables. They have been growing organically for several years and they shared with their guests some of the trials and successes they have encountered along the way. They had a disastrous year in 2012, losing their entire crop to a late frost in May that followed a very warm March which pushed bud development far ahead of their normal schedule.
Insect pests have been with us from the dawn of time and often seems to be a losing battle. Integrated pest management (IPM) has done much to advance pest control. Biological control using species-specific predators has shown great promise as it continues to evolve. Physical barriers such as kaolin-based sprays serve to hinder feeding by that group of insects that feed on fruit and foliage. Oil-based sprays not only form a physical barrier but will also suffocate those bugs which fall in the path of the oil stream. The use of dormant oil sprays is acceptable in the orchard when in the start-up phase until the ecosystem is well established but there are herbal alternatives available which serve to accomplish the same results.
BT (Bacillus thuringiensis) spray falls into the group of materials that meets organic standards. It is an organism that kills insect pests but poses no dangers to those who use it.
Michael suggests its use in situations where ‘budworm’ may have been detected. Another naturally occurring product that has been used for many years is neem oil derived from the neem tree. It acts in a variety of ways including being a repellent, acts to retard the rate of feeding and disrupts the hormonal activity of insects resulting in reduced egg laying. The use of pheromone traps have long been used successfully in trapping Japanese Bettles and using the same principles traps have been developed that are used in snaring other insects in the organic orchard.
Some diseases such as apple rust must have cedar trees in the surrounding area to complete its two year life cycle. Without their presence as alternate hosts, the cycle should be broken. Cedars must be considered incompatible with good orchard management and converted into fence posts. Among the many, many interesting facts that emerged during the afternoon session was that it takes between 20-40 leaves to support one developing fruit thus one of the reasons for thinning developing apples. The greater the number of leaves available to support a developing fruit the better the quality of that fruit is probably going to be.
The search continues for new products and methods to control both fungal and insect pests that meet the organic orchardist’s criteria. One such product is Grandavo derived from a newly discovered bacterium which produces compounds that contribute to complex modes of action. Control of moths and mites is achieved through repellency, oral toxicity, reduced egg hatch and lowering the ability to reproduce. Another newer control product is the granulosis virus which is marketed under the names Virosoft and Cyd-X and when used in the correct time sequence is highly effective against the coddling moth larvae. Entrust is the trade name of another product that is derived from a naturally occurring soil organism, which has some limitations but useful when used under the recommended conditions. On the low tech side, cardboard bands can be wrapped around tree trunks, preferably smooth trunked varieties, which provide a nesting spot for Coddling Moth larvae to pupate. These are removed and destroyed once the cycle is finished.
Those in attendance at this workshop came away with new ideas to make their own operation more productive, more profitable and more enjoyable. NOFA is to be commended for yet another most worthwhile program.
Orchard health workshop
by George Looby, DVM