Orchard Health
When talking to people about farming, I have discovered that many people believe organic farming is simple and little attention is given to the orchards. I have talked to people that think all organic farmers do is wait for the fruit to grow but they couldn’t be more wrong. Growing fruit organically is a tedious task that requires much more attention and science than conventional farming. When considering “Orchard Health,” there are 3 main subjects we take into consideration:

Nutrition (the nutrition to help the trees grow and produce good fruit)
Insects (insects that attack the trees and fruit)
Diseases (Just like people, trees can get infections)

Nutrition
Knowing what to do with the nutrients in the ground that are available to the trees is a scientific process. Each nutrient in an orchard will have a different effect on trees. Even different combinations of nutrients, the amount of a nutrient that the tree absorbs, and the time of year the tree absorbs the nutrients will greatly affect a tree and its fruit.

The first step is to discover the nutrients that are presently in the ground and available to the trees as well as the nutrients that are currently in the trees. Discovering the levels of nutrients in the trees and the ground will give us an idea how our fruit may turn out this upcoming season. If we see that a nutrient is lacking, we can take action to fix it.

The nutrients in the ground do not change rapidly so a soil sample taken once a year will give us enough information to correct an out-of-balance nutrient. A leaf sample will tell us if the trees are actually absorbing the nutrients that they need out of the ground. If it appears that the trees are not absorbing an essential nutrient, it can often be applied directly to the trees and absorbed through the leaves. These samples are usually taken from July through August so when harvest is completed corrective measures may be taken in the fall to supply next summer’s crop with the nutrients the orchard needs.

Here are a couple examples of what we are looking for and what we may expect the results will be if no action is taken.

• If Nitrogen is too high in the ground we can expect suckers to grow and pits to split from rapid growth the excess Nitrogen caused.
• If Manganese is too low we can expect to see splitting pits.
• We may find we have good levels of Zinc, but if Potassium is too high it will bind up the Zinc and prevent the tree from absorbing it.
• If we find that Boron levels are low, buds won’t set and we won’t get fruit.

To prevent these situations and many other possibilities from happening we will apply substances that contain the nutrients we need to put our nutrients back into balance. Currently we are applying Organic Compost to our organic Peach orchard. This compost is made from the yard clippings and leaves that people put into the green barrels in the cities.

In the spring the trees are no longer dormant and starting rapid growth. Giving them Nitrogen while they are growing is like giving a growing child sugar for breakfast, lunch, and dinner. It will rot the kid’s teeth right out of his mouth. Excess N in the spring will subject the roots to rot and leaves to mildew. It will also cause such rapid growth to the fruit that will cause the pit to split in half. Because knowing what to apply and when to apply it is so important, we keep a close relationship with our highly trained crop adviser who is a Certified Crop Adviser as well as a licensed Pest Control Adviser.

Insects
Keeping good Orchard Health is also keeping control of the pests in the orchard including anything from bugs to bacteria. Here are just a few insects that organic farmers encounter.

Brown Mites feed on the trees and takes the nutrients from leaves and branches which will turn leaves yellow and weaken trees. To fight this pest we often release another mite into the field called the Western Predatory Mite that loves to feed on the Brown Mite. Another helper is the Brown Lacewing which nearly everyone has seen flying around in the spring. When the Lacewing is a larva, it is a mite eating machine.

San Jose Scale will crawl on the trees, pick a spot, and start feeding. Although they are very small they inject toxins into the tree while feeding. This can damage branches if scale populations get out of hand. To keep San Jose Scale under control, an organic oil is applied in a spray to the trees that will simply smother the small scale. Scale also has many enemies including Lady Bugs.

The Peach Twig Borer hibernates through the winter as a larva in a small chamber it made in young tree limbs. This often kills the young shoots or limbs. The Peach Twig Borer in the summer will eat on the fruit.  To prevent these moths from making families in our orchard we interfere with their mating. We cover the orchard with the same pheromones that the female Peach Twig Borer emits. After this pheromone is dense in the orchard the male moths don’t know where to look for a mate. Moths that somehow find each other often get their offspring eaten up by the gray field ant.

Diseases
Bacterial Canker is a bacteria that can kill limbs and cause the tree to produce a gummy sap. The tree will then start producing suckers when branches begin to die. Peach Leaf Curl is a fungus that will cause the leaves to curl, twist, and grow thick as if they have a cancer. These infected leaves can begin to fall and cause branches to die. To prevent either of there problems from occurring, we apply copper to the trees. It is a natural element and a certified organic step we use to prevent these diseases.

To learn more about protecting your fruit trees visit the University of California Davis website for some great advise specific to different crops. Michael Colombo Bella Viva Orchards Michael@BellaViva.com Orchard Health Video