(Reprinted with permission of Ag Alert, a publication of the California Farm Bureau)
Published: Jan. 17, 2001
By Christine Souza, Assistant Editor
Pull out old trees. Closely examine nitrogen levels. Utilize
foliar nutrient sprays. Stay away from spray
additives. These are just a few money-saving suggestions that
John Edstrom, University of California Cooperative Extension
integrated pest management advisor, provided growers at the
recent Sacramento Valley Dormant Season Meeting in Live Oak.
"I'm here to learn as much as possible. I was most
interested in the talk on cost savings," said Jim Tarkey, a
long-time almond grower from the west side of Butte County.
"Price has not been good for almonds. We were getting about
$2 per pound and now the price is 80 cents per pound. We have to
find
anything we can to save money."
Almond growers from Colusa, Yuba and Sutter counties gathered at
the Spilman orchard to gain insight on cutting costs.
"Reductions in cost must be made carefully with
consideration for per-unit costs, or the cost to produce a pound
of almond meats. Balancing inputs in each block based on yield
potential is foremost," Edstrom said.
Edstrom, a Colusa County farm advisor for almonds, suggests that
growers, at the end of the season, remove older product blocks to
promote rejuvenation. Prime candidates for removal are areas
affected by trunk cankers and root and crown disease. Most
pruning can be omitted in orchards within four to
five years of removal. One-half of the normal rate of nitrogen
fertilizer can also be omitted if orchard removal is expected in
one to two years. Replants should be discontinued within six
years of orchard removal. Paying close attention to fertilization
of almond trees can save money.
"I'm getting firm in the idea that we do not need nitrogen
levels above 2.2 (percent leaf nitrogen level). There are some
varieties that need less fertilizer," Edstrom said.
"And I hope nobody is putting fertilizer on in the winter
anymore. That is very wasteful and a poor practice."
It is realistic to reduce nitrogen levels by 30 to 50 percent
when under flood and sprinkler irrigation, and with micro and
drip irrigation, 20 to 30 percent is appropriate. Growers may
improve efficiency of fertilizers by splitting nitrogen
applications or injecting continuously with micro and drip, and
also, by avoiding excess irrigation. Ensure leaf nutrient levels
are monitored when adjusting fertilizer programs.
Growers should purchase only the least expensive sources of
nitrogen such as ammonium sulfate or urea in dry form and UAN-32
in liquid form.
To measure potassium levels, analyze leaves in June or July and
adjust
application rates as needed. "Heavy amounts of potassium
have been applied in recent years, probably too much in many
cases," Edstrom said.
Values above UC-recommended levels of 1.4 percent have not
increased yield in repeated tests even in high-yielding blocks.
Avoid soil-banding potassium in drip orchards unless the band can
be put on top of the wetted area. Material placed outside this
area will not move into the root zone and much
will be wasted or greatly delayed in availability. Inexpensive
sources of potassium are potassium sulfate and potassium
chloride.
Gypsum applications have been used effectively to correct soil
imbalances or water penetration problems, but this remedy also
appears to be overused. In many cases, little benefit has
resulted so it is important to use side-by-side comparisons to
ensure gypsum is needed. "Gypsum is wonderful and
cost-effective. Be sure to put it on where you need it and not
where you don't," Edstrom said.
Complete fertilizers, such as materials which contain nitrogen,
potassium and calcium, tend to be very expensive and in many
cases unnecessary, Edstrom said. "For the past 20 years at
the Nickels Soils Lab we have produced over 3,000 pounds (of
almonds) per acre without applying complete fertilizers. Tests on
newly-planted trees comparing nitrogen alone vs. complete
fertilizers have shown no benefit beyond nitrogen," Edstrom
said. "I would really question that (spending the money on
these)."
He suggests foliar nutrient sprays can save money on the farm.
Although they cannot substitute for soil fertilizers, foliar
potassium, zinc and boron are justified if lab samples indicate a
need. Edstrom feels many other mixtures are a waste of money, but
exceptions may include rare instances of sandy or
very low-fertility soils. New research on the severe almond bud
drop problem associated with bacterial canker and sandy soil
points to some benefit from foliar calcium. Other spray materials
such as the sugar-based Fulcrum have not proven to be beneficial
to almonds.
Almond growers can get away with inexpensive treatments by using
beneficial predators as part of a pest management program, he
said. "Avoiding the use of disruptive sprays is the key to
this entire low-cost, non-toxic pest management program so
important in our industry today," Edstrom said.
"Preserving predators nearly eliminates the need for spider
mite control when orchards are well-irrigated. When mite sprays
are necessary, inexpensive summer oil treatments are generally
effective if applied early."
The dormant spray can be eliminated without pest problems if the
orchard is not sprayed in-season with disruptive insecticides
that kill the beneficials. Disruptive materials include synthetic
pyrethroids,
organophosphates and carbamates. He said navel orangeworm sprays
make this difficult, but adequate control can be achieved using a
combination of early harvest, orchard sanitation and soft-spray
materials. Without toxic sprays, San Jose scale and brown almond
mites can be controlled with beneficials and
dormant oil sprays.
Edstrom stated that spray additives used to control pests and
diseases are a huge waste of money. Most all additives can be
omitted unless they are called for on the label or are needed for
pH adjustment. The majority of fungicide and insecticide trial
protocols do not call for additives and tests have obtained
excellent pest and disease control without them.
Irrigation and pruning are other areas in which almond growers
can penny-pinch. Edstrom suggests pre-season and in-season soil
moisture levels can be monitored and irrigation can be reduced
during hull split. Some recent research shows pruning can be
reduced in tightly-spaced trees. Until this concept is proven, a
standard or "minimum pruning" program should be
followed. Large trees at spacings of less than 100 trees per acre
require more traditional training and pruning methods, while
smaller trees in
closely spaced blocks need less. Alternate-year pruning can also
save costs in mature orchards. Pole-mounted chain saws can
increase pruning crew efficiency. Moderate use of machine topping
or hedging is a cheap way to open up crowded orchards.