Ben Faber, Farm Advisor and Mary Lu Arpaia Extension Specialist
Sometimes growers respond to “DO's”. Do plant on mounds or berms, Do use avocado clonal rootstocks, etc. But sometimes we respond better to “DON'Ts”. Don't plant in wet soil. Don't bury the stem when planting. Don't apply foliar nutrients to avocado. So here, is a list of Don'ts that might make more of an impression than Do's. And some of the Don'ts are actually Do's, so read them well!
Prior to Planting
Don't do a soil analysis to determine suitability. You don't want to know what the pH is or salinity, or where a hard pan might be or areas of waterlogging or high winds. If you know before planting, you can make alternative arrangements, like correcting soil pH or leaching to correct salinity. That's too much work.
Don't chose an appropriate rootstock. Whether you are planning for citrus or avocado, select appropriate rootstocks for the site. Citrus has many more options than avocado, but even with avocado, some rootstocks are more tolerant of certain conditions, such as root rot, salinity and high pH.
Don't consider incorporating pollinizers in an avocado orchard. They might create more fruit.
At Planting
Don't plant on berms or mounds when there is potential for poor water or air drainage. Maintaining good water management which berms can help, can lead to the long-term health of the orchard.
Don't mulch at planting. This keeps weeds down, reduces evaporative loss and provides some control of avocado root rot.
After Planting
Don't control gophers and ground squirrels and rabbits and mice. They can be especially hard on young trees, but older citrus stems are always a sweet dessert for rodents.
Don't walk the orchard irrigation system, to check for leaks, breaks and non-uniformity.
Don't' have an irrigation system evaluation. It might point out how to better apply water and grow a healthy tree and more successful operation.
Don't prune, thin or manage tree height and size for optimum production.
Don't use irrigation in anticipation of and during frost or heat events.
Don't whitewash trees to prevent sunburn damage of exposed branches after heat or frost damage
Don't do fall leaf analysis to assess fertility needs and management
Don't walk your orchard to assess conditions and observe how harvest and pruning operations are progressing. Walking the orchard only at harvest time means if poor tree conditions have progressed it's harder to correct.
Don't do ground management with cover crops, mulch or various erosion control practices that lead to soil health.
Don't improve conditions for improved avocado pollination and fruit set. Consider promoting biological control through use of hedgerows, cover crops, pesticide use, fertility/pruning/irrigation and other horticultural practices.
Harvesting
Don't coordinate with your packer on the harvest; this might lead to better fruit quality and higher returns.
Don't pay attention to minimum maturity standards for citrus and avocado; they are just cumbersome regulations.
Don't worry about mixing avocado varieties in the bin, what is the consumer going to know or care?
Don't pay attention to the weather. Extremely hot weather coupled with delays delivering the fruit to the packinghouse may result in a loss of fruit quality and actual weight loss/size from the field to the packinghouse. Likewise, picking wet citrus can lead to peel disorders that only manifest after the fruit is packed.
Don't visit the picking crew while they are picking to inspect the quality of the harvesting job. What harm does a few long stems on citrus for instance do to fruit quality? Or if you are size picking to meet market demand, does it matter that there is a lot of undersized fruit?
These are all sarcastic Don'ts, but there are some real Don'ts that growers forget about:
Don't plant into wet soil. It leads to compaction and poor root growth.
Don't make a hole just as deep as the planting sleeve. Making a deeper hole can lead to the root ball settling and eventually covering the tree stem which can lead to stem cankers.
Don't incorporate an organic planting mix. This leads to decomposition and eventual settling of the material around the football and the stem getting buried.
Don't let the mulch accumulate around the trunk, leading to crown rot.
Don't let mulch fall into planting hole. Same as incorporating in the planting media.
Don't incorporate a fertilizer in the planting hole. The tree is loaded from the nursery and there is a good chance of burning the roots.
Don't spray when wind speeds exceed 10 mph If you are spraying pesticides, no matter how close you are to finishing or how little is still left in the tank. Famous good intentions that backfire.
And for those who prefer a more positive approach, using Do's, here's another way of listing field activities. Remember that every situation is different and avocados may be more sensitive to some of these Do's than citrus and other deeper-rooted trees crops. So said another way:
Do soil testing prior to planting.
Do choose appropriate rootstocks.
Do mulch at planting, keeping it away from the tree stem and don't incorporate an organic planting mix in the hole.
Do incorporate pollinizers.
On flat ground, shallow ground, Do plant on berms or mounds, especially avocados.
Do make a hole no deeper than the root ball and make sure it's not sloppy wet when digging and don't backfill with organic planting mix. Use the native soil. And don't put fertilizer in the planting hole.
Do mulch trees, especially avocados.
Do control rodents, especially in citrus and young trees. But even mature citrus can collapse in a weekend of gopher feeding.
Do an irrigation system evaluation and walk your irrigation lines frequently.
Do maintain tree size, preventing tree shading of neighboring trees and self-shading.
Do use irrigation system for winter warming and cooling during heat spells.
Do whitewash trees after defoliation to prevent sunburn damage.
Do leaf analysis to optimize fertilizer applications.
Do walk the orchard to evaluate conditions before they get worse.
Do make pesticide applications following all guidelines.
Do optimize the orchard for biological control, soil health and tree performance by keeping as much of the ground covered with mulch or cover crop, and including alternative pollen and nectar sources from hedgerows.
Do make sure the trees and orchard are getting the right amount and timing of as good a quality of water as possible.
Do coordinate with your packer on timing of harvest and delivery to the packinghouse to optimize fruit quality. You don't know where your fruit is going to go in the national and international market and it is important that we all do our part to maintain the excellent reputation of California citrus and avocado.
Do pay attention to fruit seasonality and variances between growing seasons. Paying attention to the market while picking fruit of optimal quality is an important balancing act. Don't play the late market unless you can actually hold your fruit late.
Do pay attention to weather when you are planning harvests. Keep in mind that the fruit are living and will respire and lose moisture. Keeping fruit in the shade will minimize weight loss before transport to the packing house. Keep the time in the field after harvest to a minimum.
Do inspect the harvested fruit before it leaves your grove. Make sure that stems are short and will not cause puncture wounds (= decay) on adjacent fruit. Make sure you are not mixing avocado varieties in the bin since they will likely be graded out at the packinghouse anyway and will at the least result in an uneven looking packed box.
There are so many Don'ts that it's hard to list them all. The best is this one:
The last Don't is, don't attend grower meetings like those sponsored by CA Citrus Research Board, CA Avocado Society, CA Avocado Commission, CA Assocation of Pest Control Advisers, Pesticide Applicators Professional Association, Groundwater Management group or other grower organizations. Don't stop learning.
If you have some other outstanding Don'ts, Do pass them on to me. Do continue learning and being inquisitive.
