Mapping Your Orchard

By Nick Sakovich

The advent of the computer age has enabled us to accomplish many wonderful things for agriculture -- from irrigation scheduling to payroll. Even accomplishing such complicated feats as satellite metering of precise amounts of fertilizer to very small increments of land. Now it’s time to let the computer help with another tedious task.

The question may arise, should I pull Block A ? It just dosn’t look good. Well, first of all, what percentage of the trees are healthy, what percent are dead or dying, and what’s in between? For years, you have been keeping an eye on another block, wondering when you will pull it. In this case, it would be good to know the rate of decline over the years; is it slowing down or is it getting worse? These are all questions a grower needs to know in order to make some very important decisions. We are talking about land efficiency; the potential of each tree site to produce its optimum yield. Dead trees, or those close to it, are obviously just taking up space and should be replaced with productive ones. Likewise, what about those in between trees that don’t look all that well, but certainly aren’t bad enough to pull? How many years are they going to stick around, producing less than optimal yields? The fact is, there are many trees within a given block that are producing substantially less than what that space could or should be producing. Perhaps in the future, as each tree is picked, a minicomputer will instantly calculate the amount of fruit removed, enabling the grower to then remove those trees which are least productive.

But until that day comes, it is very important for each grower to know the health status of each one of his trees. How can this tremendous task be accomplished? The answer is mapping. Each tree in the orchard needs to be rated and assigned a number which corresponds to a particular degree of health. A rating system of 1 to 5 works quite well; 1 being healthy and 5 being dead. This particular system can certainly be modified according to the needs and desires of the grower.

Assigning a rating of 1 or 5 is not difficult; it's either a darn good looking tree or, it's dead. Whether a tree is rated 1 or 2 is not critical. A 4 should not be hard to recognize, since the tree is close to death. A 3 is probably the hardest; you might be tempted to rate a bad 3 as a 4, or a good 3 as a 2. This is important, since the tree will either improve to a 2 or falter to a 4, which would then need to be removed. Be advised, as you are rating your first couple of rows, modifications will almost certainly take place.

One important and obvious reason for rating each tree is so the poorest trees (4 and 5) can quickly be identified and removed in order to make way for more productive trees. It is important to understand that a tree may look good at present, but may need to be rated a 4, if, for example signs of oak root fungus or extensive gummosis or gopher damage are seen. Conversely, if a particular tree looks poor, it may be given a better number if you know what is contributing to that poor condition, and you know it is temporary.

After you’ve walked many miles of orchard, you may well wonder, how has the computer helped me with this; it hasn’t. But now you can take your ratings and enter them into the computer. Graphics 1-4 are printouts from just such a rating system.

One gets a clear and immediate visual representation of what the orchard looks like. You can see exactly how many good trees you have and how many bad trees. Now, informative decisions can be made. In addition to helping make important decisions for the present, like getting rid of all the 4's and 5's, the charts can also be used for important future resolutions. One, two, or even three years down the road, the trees can be rated again, and their progress evaluated. Your fertilization program, irrigation schedule, or any other newly implemented program can quickly be evaluated. (Keeping in mind there may be other variables present beside your new cultural method).

Being able to evaluate each individual tree and graphically see, in an encapsulated picture, the varying degrees of tree health will tremendously help a grower to more intimately know his orchard and thus prepare him to better make those important decisions. This method will indeed allow the grower to utilize his land as efficiently as possible.