Page 19 - Griffin Gazette Issue 1 - 2019

CEA CROPS CHEMICAL BCA OPTION FOR

SUSCEPTIBLE TO CONTROL OPTIONS ROOT APHIDS

ROOT APHIDS Successful treatment of root aphids The soil predatory insect Atheta coriaria,
in CEA production systems requires or rove beetle, is known to prey on root
Root aphids can infest hydroponic attention to a few factors. Drenching aphids, but the level of control has not
lettuce crops, spinach, basil, cannabis to control pests below the soil line been determined by research. Rove
and other herbs. Different species is a method that involves thorough beetle are recognized predators of
occur on the different CEA crops. saturation of insecticide into the fungus gnats, thrips pupae and shorefly
Some common management strategies substrate. Insecticides should be larvae. Rove beetles are nocturnal; adults
apply to all crops: drenched on moist media to optimize fly and the larvae are active and mobile.

1. Scouting is critical for early detection chemical penetration. Insecticide Contrary to popular belief, there are no
(see digital Gazette for scouting tips) drench options are very limited known beneficial, entomopathogenic
in hydroponics, deep water float
2. It is best to remove severely infested beds, ebb and flow systems, as few nematodes that will parasitize
plants from production products are properly labeled for root aphids.
3. Treatment should continue until the use in these systems. The simplest SUCCESSFUL
pest is no longer detected option to manage root aphids in
hydroponics would be to drench in
The most common type of root aphid the liner stage, prior to moving the MANAGEMENT OF
found in lettuce is the lettuce root aphid, crop to the recirculating system. For
Pemphigus bursarius. They're found in cannabis, options can be even more ROOT APHIDS IN
clustered groups and distinguished from limited; follow recommendations CEA CROPS
other root aphids by short antennae from your state. Some states allow
and undeveloped cornicles. Their waxy the use of EPA-registered products Discovering root aphids can be
coating can limit pesticide efficacy. while other states only allow the discouraging for growers due to
Pemphigus root aphids can also infest use of 25(b) products. Keep in mind challenges in achieving control. Scouting
herbs. Regardless of crop, infested that 25(b) products are often less is key to catching problems early. If you
plants will wilt during the day. Watch for effective compared to EPA-registered discover root aphids, take quick action
yellowing and stunted leaves, stunted pesticides. to discard highly infested plants and
plants and malformed heads. Extremely Altus (flupyradifurone): May be applied determine the extent of the infestation.
high populations can cause plant as a drench to cucumbers, lettuce, Remember to always read and follow the
death; discard heavily infested plants. peppers and tomatoes. product label, especially when it comes
If possible, cultivate root aphid resistant to treating edibles and cannabis crops.
lettuce varieties. Ancora* (Isaria fumosorosea Apopka
Strain 97): Naturally occurring fungus
The rice root aphid, Rhapalosiphum for drench application to CEA crops.
rufiabdominale, occurs in cannabis Repeat applications at 3-10 day More to see online
crops. Rice root aphids are olive-green intervals. Most effective when relative See our digital Gazette for more
with a relatively round body. Wingless humidity is 80% or higher for 8-10 information on root aphids.
forms develop on roots and survive in hours. OMRI.
all types of substrate. Offspring mature
in about 9-10 days. The adults can live BotaniGard 22WP* (Beauveria
for a month producing several offspring bassiana Strain GHA): Naturally
daily at 73°F. In cannabis, root aphids occurring fungus for use as drench on
are often detected when plants show vegetable crops in greenhouses and
chlorosis (yellowing of the leaves) or outdoor production.
stunting. Growers sometimes mistake AzaGuard (azadirachtin)*: Plant
root aphid infestation for nutrient derived, insect growth regulator for use
imbalance. If you suspect root aphids, as a drench. OMRI.
carefully scout the root system.
Azatin O (azadirachtin)*: Plant derived
insect growth regulator. OMRI.
* Allowed on cannabis in some states.
Check your state’s approved list of
active ingredients for cannabis.