Pre-Season Vegetable Pest
By Patrick Cavanaugh, Editor,
And Laurie Greene, Associate
On Wednesday, Imperial Valley growers and
PCAs gathered at the UC Desert Research and Extension Center in El Centro to
hear updates on pest management and spray techniques. It was all part of the
preparation for the 2014 crop year.
The director of the center, Sam
Wang, welcomed everyone and introduced all speakers.
Dr. Antoon Ploeg, Associate Nematologist and Associate Cooperative Extension
Nematologist, UC Riverside, addressed nematode management in vegetable crops.
He focused on three major nematode species including:
Research shows that these
nematodes live for approximately one year, but propagate during that time. Needle
nematodes are present at all soil levels, but prefer deeper root-level soil and
like warm weather. Thus, they are found worldwide in hot areas, including
Imperial County and Mexico.
“Needle nematodes’ presence
in a field tends to be unevenly dispersed, so scientists do not report levels
per se; they report that the field either has or does not have nematodes,”
These parasites may propagate
five times per season. They are found on many vegetable plants, and studies
have analyzed nematodes in beans, tomatoes, pepper plants, cabbage, and brussel
Of the three different
species mentioned that affect many crops in California, Ploeg said, “Root Knot
nematodes are the most damaging of the nematodes, as they enter the roots and
cause severe galling of the roots. They thrive in sandy soils.”
Ploeg noted that the industry
is looking for new materials for protecting crops from this troublesome
nematode. “We have Vydate and there are several novel materials in the
pipeline. Some of those products look very promising.”
This nematode is particularly
troublesome on Imperial Valley sugar beets and on cruciferous crops throughout
Nematode control research is
ongoing with work on anaerobic soil disinfestation—a practice of mixing compost
matter in the soil that heats up to certain levels that kill the cyst nematode.
a UC Farm Advisor in Imperial County, spoke about new and old materials for
pest control in cool season desert vegetables.
In looking at materials that
control worms, whiteflies and aphids, Natwick asked two questions: “Are these
newer materials as efficacious as the older materials?” and “Are the new
Some of the newer worm
control products include Anthranilic Diamide insecticides (Synapse, Coragen,
Verimark, Volium Express); Spinosyns (Success and Radian); IGRs (Intrepid and
Rimon) and others such as Torac.
Newer aphid controls include
Movento, and Beleaf.
Newer whitefly control
materials include Neonicotinoids, Movento Oberon, Coragen and Verimark &
Exirel, Brigade (a pyrethroid), and Torac.
Pros and Cons of New vs.
The Pros of old vegetable insecticides include:
· Resistance Management partner
· Fits existing IPM program
The Cons of old vegetable insecticides:
The Pros of new vegetable insecticides:
· Resistance rotation partner
· Environmentally friendly
The Cons of new vegetable insecticides:
Natwick then considered the
premixed in-the-can materials: Why? Or Why not?
Premixed in-the-can Pros:
· Cheaper than “in-the-tank mixtures
· Convenient for mixing and loading of the sprayer
· New product for the company with old active
· Broad spectrum insect control
Premixed in-the-can Cons:
· Confound insecticide resistance management.
· Environmental exposure of a.i. when pest is not
present (always potential for environmental harm)
· May not be more efficacious than one a.i.
· Takes tank mix decision away fro PCA or grower (more
important that PCAs keeping more control of input, need flexibility)
Milt McGiffen, UC
Riverside CE Vegetable Crops Specialist and Plant Physiologist spoke about nozzles,
surfactants, and sprayer parts.
Nozzles are important to the
private applicator because they:
· Control the amount –GPA
· Determine uniformity of application
· Influence the drift potential
In a diverse agricultural
region like Imperial Valley, there is a high potential for drift to injure
- Decide systemic or contact material. Need knowledge of
- What is target?
- Broadleaf (smooth, hairy, waxy)
- Leaf orientation – time of day
- Disease prevention
McGiffen spoke about spray nozzle
basics incorporating the different types of nozzles and their spray patterns,
which include flat fan, even fan, and modified flat fan.
“Droplet size less than 200
microns in size are highly driftable and should be avoided,” McGiffen said.
Factors affecting drift are
drip size, nozzle type, nozzle size and nozzle pressure (which the applicator
Weather can also affect drift
including air movement, direction, velocity, temperature, humidity, air
stability/inversions (not an advisable time to spray) and topography (low and
McGiffen also spoke about the
importance of adjuvants. He said growers and PCAs should always follow the
label suggestions on the type of adjuvant to use with a spray material.
Barry Tickes, with
the University of Arizona Yuma Ag Center, spoke about the lack of good
herbicides for lettuce crops in Arizona and California.
Of the new pesticides
registered for leaf lettuce in the last 10 years, 15 were insecticides, four
were fungicides and -1 was an herbicide (negative since Kerb was pulled off
Tickes noted that the
registrant for Kerb has been working hard to complete necessary studies to get
it reregistered, and hopefully it will be available in about three years.
Tickes said the EPA is
allowing a Section 18 Emergency Exemption, “but we will have a tough time
getting approval because one of the first questions they has is if there is an
“We can always use hand labor
to get the weeds out, but that would not be cost effective for growers,” Tickes
said. “But there are exemptions in the area that—without the material—could result
in an economic loss, which may qualify.”
herbicides may come from new uses of old products registered on other crops,
such as Pursuit; however, its low rate will most likely not be enough for
“We are also looking at new
application techniques and genetics,” noted Tickes. “Herbicide-resistant lettuce
has been developed, but genetically-modified lettuce will most likely never be
approved by consumers.”
Tickes surmised that
mechanization might be the way to go. “This new machine does a remarkable job
in large scale weed control as well as lettuce thinning."
Labels: Antoon Ploeg, Barry Tickes, El Centro, Eric Natwick, lettuce, Milt McGiffen, Nematode, Nozzle, Pre-Season Vegetable Pest Management Workshop, Sam Wang, Section 18 Emergency, UC Desert Research, UC Riverside