Barrett A. Courville | 1/21/2011 11:23:45 PM
Citrus Question of the Winter
By far, the most common question that I have received about citrus trees this winter is why the tree did not produce as much as it did last year. Well, there are several possible explanations. To begin with, we had a severe winter in 2009-2010. Many trees received freeze damage and lost productive branches. We were lucky. They could have died from the freezes. In spring, the damaged trees spent most of their energy and nutrients in an effort to replace lost tissue and branches. This was at the expense of fruit production. Another related factor was the late arrival of warm weather in the spring. As many trees were blooming at the normal time, we experienced abnormally cold weather in the late spring (if you don’t believe me, just ask a rice farmer). These cool temperatures caused many blooms to die before they could be fertilized by pollen. No fertilization, no fruit on that bloom. We also underwent a short, but severe drought in the early summer. Many of the young fruit died and fell from the tree in an effort to save moisture for the tree. Add to all this, that in the previous winter, we had one of the largest productions of citrus fruit in memory. To produce this bumper crop, the trees depleted many nutrient and moisture reserves in the main body of the tree. So they went into a harsh, prolonged winter and a dry summer without much reserve to produce fruit.
County agents may seem to blame a lot on the weather. That’s because the weather is responsible for a lot. We can do everything we are capable of, but if Nature doesn’t cooperate, we will not succeed as well. Let’s hope for a more favorable environment for this year.
It’s time now to perform one of the tasks to help your citrus or other fruit trees.
Fertilizing Fruit Trees
Earlier this month I discussed the importance of properly fertilizing shade trees and shrubs in the home lawn. It is equally important to maintain proper fertility for the many species of fruit trees we have for home production. January through February is the preferred time of year for fruit tree fertilization. Proper applications at this time of year will help assure that plant nutrients are in adequate supply for the entire growing season. The better start you give the tree, the better chance for optimum production this year.
All plants remove nutrients from the soil, use them to produce food, use this food for fruit production and store the rest in the tissues of their trunk or stem to initiate new growth in the spring. Keeping an adequate supply of plant nutrients in the soil is essential for continued growth and production. The major nutrients used by the plant are nitrogen, phosphorus and potassium. These are the nutrients used in the greatest quantity. To assume that they are present in proper amounts, we add fertilizer to the soil. A late winter application of fertilizer will accomplish this when the need for nutrients is greatest for fruit trees.
Citrus trees are usually provided with one and one-half pounds of 8-8-8 fertilizer per year of age up to a maximum of 12 pounds per tree (eight years of age). In June, an additional one-half pound of ammonium nitrate per year of age up to a maximum of 10 pounds (20 years of age) can be applied. The additional nitrogen in June helps promote leaf development and greater food production.
Fig trees in general need one pound of 8-8-8 per year of age (up to 10 pounds maximum). Blackberries need one-half pound of 8-8-8 per row foot in late winter. Apply an additional one-half pound of ammonium nitrate per row foot after berry harvest. Pecan trees receive three pounds of 8-8-8 or equivalent per inch of trunk diameter measured one foot above the soil line. Older pecan trees (25 years or older) need an additional one-half pound of ammonium nitrate per inch of trunk diameter. Apply this in May or June. Following this formula, you will find that pecan trees are quite expensive to fertilize properly. Many home gardeners have decided to treat the pecan as a shade tree and be happy for any nuts that it provides.Livestock Shows