Avocado Record Keeping - 1996
Plop, plop. The sound of fruit dropping. Ever wonder how much fruit is lost from windfall or the tree thinning itself in order to carry the remaining fruit? We monitored 15 trees in a 5 acre block from January to harvest in September. On a weekly basis, fruit were collected from the ground and weighed. Except after major wind storms, there was no distinct period of fruit drop until near the time of harvest. In total there was approximately two bins per acre lost, and at 68¢ a pound, this fruit loss represented about $1,400 an acre. Most of the dropped fruit was 8 ounces and larger.
At harvest, we weighed fruit from each of our treatments on a per tree basis. As many of you have observed in your own groves, some trees consistently outyield other ones. There is one tree in our trial that over a four year period has produced over 500 pounds yearly. There are other trees in the trial that regularly produce little or no fruit.
This is a research plot, but the information cited is typical of what can help a grower make better decisions. The successful avocado grower is a business person. And as in other businesses, records are necessary in order to make decisions, such as whether a size-pick is justified in light of the amount of fruit drop or whether certain trees should be removed for lack of productivity. Most growers do keep some sort of record of expense and income, but too few analyze the productivity of their trees.
The maintenance of production records takes little time and can yield considerable knowledge. One of the most impressive practices I witnessed in Israel was the yield records that were kept on each tree in an orchard. When a tree did not produce the average for the orchard over a period of time, it was removed and replaced with a potentially more productive tree.
A tree producing 100 pieces of fruit requires the same care and expense as one which produces 5 times that amount, other conditions being equal. Obviously, then, the lower yielding tree does not produce its potential profit. To know which trees in an orchard are producing optimum amounts of fruit requires a systematic set of production records. These records need to be written down, not just memorized. The data accumulated over several years, can then lead to a tree removal pattern at orchard thinning time.
These records need not be exact. A simple method which should suffice would be to make a tree-by-tree estimate prior to harvest. Note on a sheet of grid paper with tree and row numbers the amount of fruit on each tree. It does not matter that an estimate of 156 fruit is different from the actual harvest amount of 129 or 186, but that a ball park figure is obtained. The important point to arrive at is whether the tree is carrying a small or large amount of fruit.
Trees which are revealed to be unproductive over a period of time can then be replaced, grafted, or removed during an orchard thinning. The trees which are retained should be those with the best bearing habits. Analysis of the yield records will disclose how the thinning program is to be accomplished with the retention of the greatest number of high producers.
If the fruit count is done early, such as in December, this record system will also double as a guide to whether a select-pick should be made. By removing fruit early, the amount of fruit drop later on and the amount of stress on the trees will be reduced. In this way the grower can know what sort of picking program to expect in the coming year.