Montgomery County Agriculture and Food Systems

Risk Update – May 26, 2026

Fusarium Head Blight Risk Tool

High risk as of May 26, 2026; however, wheat has finished flowering. To see commentary from Extension Pathologists, including fungicide application information, click on the megaphone icon in the top right corner. 

Wheat Field Notes – June 15

Poolesville

Growth Stage:  Feekes 11.4 (harvest ready). Scattered heads infected with sooty mold. Fusarium seems to be minimal. Most spikelets had 2 kernels (the third did not develop).

June 12

Laytonsville

Growth Stage: nearing the end of Feekes 11.2 (dough stage.) Scattered heads infected with sooty mold. Fusarium seems to be minimal.

June 4

Laytonsville & Poolesville

Growth Stage: Feekes 11.2 (dough stage) 

May 28

Laytonsville

Growth Stage: Feekes 11.1 (milky fluid can be squeezed out of the kernels) Insect Pests: Aphids, brown marmorated stink bug (all low) Beneficial Insects: Spined soldier bug, spiders

Poolesville

Growth Stage: Feekes 11.2 (material squeezed out of the kernel has a doughy consistency) Insect Pests: Aphids, cereal leaf beetles (both low) Beneficial Insects: Spiders

May 21

Laytonsville

Growth Stage: Feekes 11.1 (milky fluid can be squeezed out of the kernels). Insect Pests: Cereal leaf beetle and aphids (very low)

Poolesville

Growth Stage: Feekes 11.1 (milky fluid can be squeezed out of the kernels) Insect Pests: Cereal leaf beetle (low)

May 14

General Notes

• If cereal leaf beetles are still active and have reached the threshold of 1 larva per stem, consider spraying. The larva can eat quite a lot if left unchecked; damage can still occur between flowering and the soft dough stage.

Laytonsville

Growth Stage: Feekes 10.5.3. Insect Pests: Cereal leaf beetle (very low.) Beneficial Insects: Spiders

Poolesville

Growth Stage: 10.5.3 (late flowering) Insect Pests: Cereal leaf beetle (10-15% of plants with 1 larva per stem; below threshold of 25%); aphids (low) Beneficial Insects: Lady beetles

May 7

Laytonsville

Growth Stage: Feekes 10.5.2-10.5.3 (mid- to late-flowering) Insect Pests: Aphids and cereal leaf beetle (both very low) Beneficial Insects: Spiders

Poolesville

Growth Stage: 10.5.3 (late flowering) Insect Pests: Cereal leaf beetle (10-15% of plants with 1 larva per stem) Beneficial Insects: Spiders

April 30

Laytonsville

Growth Stage: 10.3 (heading one-half complete) Insect Pests: Aphids (very low); no cereal leaf beetles caught Beneficial Insects: Spiders, green lacewing Disease Present: Leaf rust (on lower leaves, scattered throughout the field)

Poolesville

Growth Stage: Majority of field at 10.5 (heading complete); some areas of the field at 10.5.1 (beginning flowering). Insect Pests: Cereal leaf beetle (10-15% of plants with 1 larva per stem). Minor damage to the flag leaf.f Beneficial Insects: Spiders, green lacewing

April 23

General Notes

• Winter annuals are flowering and setting seed. Note heavy‑population areas and plan fall herbicide applications.
• Freeze damage is very minor. Some plants show a killed leaf, but the head and growing point remain healthy.
• Cereal leaf beetle eggs and larvae are present. Wheat is at or near boot stage.
  • Penn State Agronomy Guide threshold: 1 larva per stem at boot stage.
  • University of Delaware threshold:   “The treatment threshold is 25 eggs and/or larvae per 100 tillers. Treatment is suggested when the egg threshold is reached, and more than 50% of the sample consists of larvae.”

Laytonsville

Growth Stage: Feekes 8–9 (flag leaf visible; some fully emerged) Insect Pests: Cereal leaf beetle (low), aphids (very low) Beneficial insects: Spiders

Poolesville

Growth Stage: Feekes 10 (boot) Insect Pests: Cereal leaf beetle (moderate), aphids (very low) Beneficial Insects: Spiders

April 16

General Notes

Cereal leaf beetle eggs are present,t and larvae are hatching. Eggs may be parasitized, so thresholds focus on larvae.

• University of Delaware threshold: 25 eggs and/or larvae per 100 tillers, with >50% larvae.
• Penn State threshold: 1 larva per stem at boot stage.

Laytonsville

Insect Pests: Cereal leaf beetle (low). Beneficial Insects: Spiders, lady beetles

Poolesville

Insect Pests: Cereal leaf beetle (moderate; ~10% of stems with 1 larva or eggs). Beneficial Insects: Spiders

April 9

General Notes

Scout fields to confirm weed control after herbicide applications. Winter annuals (henbit, deadnettle, chickweed) and roughstalk bluegrass are flowering. Cereal leaf beetles and aphids are the primary insects to monitor at this time of year.

Laytonsville

Growth Stage: Feekes 5 Insect Pests: Aphids (very low) Beneficial Insects: Spiders, lady beetles

Poolesville – Field 1

Growth Stage: Feekes 5–;6; Insect Pests: Cereal leaf beetle adults low);) Beneficial Insects: Spiders, lady beetles

Poolesville – Field 2

Growth Stage: Feekes 5 ; Insect Pests: Cereal leaf beetle adults (;low); Beneficial Insects: Spiders, lady beetles

Corn Field Notes – July 15 and 24

Western bean cutworm and fall armyworm moth captures are at 0-1 per week. Pollination and fertilization that occurred during the 100+ degree days in early July have resulted in poorer kernel development. See these articles for more information on pollination during high temperatures and estimating yield. Most of the corn that was damaged by the high winds has righted itself.

July 7 and 8

Wind-damaged corn: Fields in the eastern part of the county appear to have 50% or less of flattened corn from the storms this past weekend. Corn plants may try to right themselves, so wait a few days to assess damage. If stalks are broken above the ear, the ear will still be there, but yield may be lower. Stalks broken below the ear will have a greater negative impact on yield. Scout for ear molds on any ears close to the ground and harvest early if mold is present. For more information, see this article from Purdue Extension article. Contact your crop insurance agent with loss information and to review your coverage.

Tar Spot: The Crop Risk Tool currently has a low risk for tar spot spore presence. However, scout fields, as corn is susceptible to tar spot up to R3 (milk stage).

Poolesville

Growth Stages: V13, R1 (silking), beginning R2 (blister). Insect Pests: Southern corn rootworm beetles and Japanese beetles are present in low numbers. Disease Present: Disease pressure is also low.

June 26 and 29

Laytonsville and Poolesville

Growth Stages: V10 to R1 (silks emerging). Insect Pests: Very low insect and disease pressure. Only one western bean cutworm moth caught. Trap set up for fall armyworm.

Watch for waterhemp and Palmer amaranth. At this stage, they could be a foot or a couple of inches tall; they do like hot weather, so scout fields with known populations. If you find a pigweed plant with no hairs or thorns, it’s likely waterhemp or Palmer.

June 15

Poolesville - Field 1

Growth Stage: V8  Western bean cutworm trap set up.

June 4

Poolesville - Field 1

Growth Stage: V6  

Poolesville - Field 2 

Growth Stage: V5 

Poolesville - Field 3 

Growth Stage: V4 

May 28

General Notes

Summer annual weeds like pigweed, lambsquarters, and ragweed are just emerging to about 1 inch tall.

Poolesville - Field 1

Growth Stage: V6  Slug Damage: Some slug damage on the lower few leaves; at this growth stage, the corn is outgrowing it.

Poolesville - Field 2 

Growth Stage: V4-V5  Slug Damage: Minimal 

May 21

General Notes

With the recent rains, slug damage may increase. Corn is likely tall enough to outgrow any damage; however, scout fields with smaller plants/have recently emerged. Pokeweed seedlings are emerging; established plants that are regrowing are about a foot tall.

Poolesville - Field 1

Growth Stage: V4. Some purple color from cooler weather remains. Slug Damage: Minimal  

Poolesville - Field 2 

Growth Stage: V3. Purple color from cooler weather is mostly gone. Slug Damage: Minimal 

May 14

Poolesville - Field 1

Growth Stage: V3. Leaves turning purple due to cooler weather (slower growth results in sugar buildup.) Slug Damage: Minimal 

Poolesville - Field 2 (New to this report)

Growth Stage: V1  Slug Damage: Minimal Weeds: Morning glory emerging

May 7

Poolesville

Growth Stage: V2 Slug Damage: Minimal

April 30

Poolesville

Growth Stage: VE (emergence), almost V1. No evidence of slugs present. Some moisture in the topsoil. (Can squeeze the soil into a ball, but it does not make a ribbon, explained here by the U.S. Department of Agriculture.)

April 23

General Notes

Corn’s growing point remains below the soil surface until the V6 stage. If corn had already emerged before the April 20–21 freeze, the plant should regrow even if the leaves were damaged or killed.

April 16

Poolesville

Corn was planted but had not yet emerged.

Insects:

• No slugs observed
• Wireworm and grubs present at low levels

Weeds:

• Summer annuals emerging, including pigweed species

Soybean Field Notes – August 12

Poolesville

Growth Stage of full-season soybeans: R5 (beginning seed)  

Growth Stage of double-crop beans: R2 (full flowering)

Insect Pests: In both fields, insect pests include green cloverworm, grasshopper (less than in prior scouting), green stinkbug, and aphids. Beneficial Insects: Spiders and lady beetles are present. 

August 7

Laytonsville

Growth Stage of full-season soybeans: R5 and R6. Insect Pests: Green cloverworm, aphids, stinkbugs (green and brown marmorated), grasshoppers, and bean leaf beetles; all populations are low populations. Beneficial Insects: Spiders and lady beetles are present—disease: Some present, but below threshold.

Growth Stages of double crop beans: V2. Insect Pests: Green cloverworm present, but in low numbers. Beneficial Insects: Spiders also present.

Continue to watch for waterhemp and Palmer. 

July 15

Insect pests remain at low populations.

July 7 and 8

Laytonsville and Poolesville

Growth Stages: R2 and R3. Insect Pests: Populations are low (grasshoppers, Japanese beetles, silver spotted skipper, green cloverworm, brown marmorated stink bug, and aphids). Bean leaf beetle population is higher than last week; however, they are still below the threshold (15% leaf area damaged and 5 beetles per foot of row). Beneficial Insects: Lots of spiders are also present.

Double-crop soybeans have emerged and have the first leaves unfolded (VC). Weeds are just emerging out of the ground.

June 26 and 29

Laytonsville and Poolesville

Growth Stages: V4 and R2 (flowering) 

Watch for waterhemp and Palmer amaranth. At this stage, they could be a foot or a couple of inches tall; they do like hot weather, so scout fields with known populations. If you find a pigweed plant with no hairs or thorns, it’s likely waterhemp or Palmer. 

Insect Pests: Low insect pest pressure. Japanese beetle adults are now present. Bean leaf beetle and grasshopper populations are a bit higher than previously, but still not near the threshold. Other pests present include silver spotted skipper, brown marmorated stink bug, cloverworm, webworm, and potato leafhoppers. Beneficial Insects: Spiders and lady beetles are also present. 

Depending on the insect pest and the soybeans’ growth stage, soybeans can tolerate up to 30% of leaf defoliation during vegetative stages and 15% defoliation during reproductive stages. This is often more than is aesthetically acceptable. Visit the Crop Protection Network’s website for pictures of varying defoliation levels.

June 15

Laytonsville and Poolesville

Growth Stages:  V2, V6 (about 10% of plants starting to flower), and V7. Insect Pests: Very low populations (tarnished plant bug, grasshopper, silver spotted skipper, minute pirate bug). Beneficial Insects: Spiders, ladybeetle. Diseases: None seen

June 4

I added a few more fields; to make this report easier to read, I’ll be providing a summary. (Any pest issues will be highlighted if necessary.)

Poolesville, Laytonsville, and Derwood

Growth Stages: V4, V3, and VC. Insect Pests (all low populations): Bean leaf beetle, green cloverworm, silver spotted skipper, brown marmorated stink bug. Slug Damage: Minimal. Beneficial Insects: Spiders, ladybeetles. Weeds: Marestail 6-18 inches tall. Pokeweed and hemp dogbane are beginning to flower. (This is good news for upcoming postemergent herbicide applications because at the bud to boom stage, it is easier for systemic herbicides to move down to the roots and provide higher control.)

May 28

Laytonsville

Growth Stage: VC  

Poolesville

Growth Stage: V2  Insect Pests: Bean leaf beetles (low) Slug Damage: Minimal

May 21

General Notes

With the recent rain, scout fields for slug damage, especially if the soybeans are just emerging or only have a couple of leaves emerged. Pokeweed seedlings are emerging; established plants that are regrowing are about a foot tall.

Poolesville

Growth Stage: V2  Slug Damage: Minimal

May 15

Poolesville

Growth Stage: VC  Slug Damage: Minimal

Laytonsville

Growth Stage: VE  Weeds: Crabgrass emerging

May 7

Poolesville

Growth Stage: VC (unfolding of the first unifoliolate leaves) Slug Damage: Minimal

April 30

Growth Stage: VE (emergence) - VC (unfolding of the first unifoliolate leaves). No evidence of slugs present. Some moisture in the topsoil. (Can squeeze the soil into a ball, but it does not make a ribbon, explained here by the U.S. Department of Agriculture.)

April 23

General Notes

If soybeans had emerged before the April 20–21 freeze, they may show signs of damage.

• If damage occurred above the cotyledons (the first thick leaves to emerge), the plant can regrow.
• If damage occurred at the hypocotyl (the hook that first emerges) or at the cotyledons, the plant cannot recover.

Poolesville

Growth Stage: VE (emergence). Insects: No slugs observed.

April 16

Poolesville

Soybeans were planted but had not yet emerged.

Insects: No slugs. Weeds: Summer annuals, including pigweed species, emerging

Sweet Corn Field Notes – August 12

Corn earworm moth captures are very high (35 per day); a 2-3-day spray schedule is recommended. This is likely the peak flight.

July 24

Corn earworm moth captures are lower this week (3 per day), but a 4-day spray schedule is still recommended.

July 7 and 8

Corn earworm moth captures are 4-8 per day; a 4-day spray schedule is recommended.

June 26 and 29

Corn earworm moth captures were 2.5 and 4 per day; a 4-day spray schedule is recommended.

June 22

Poolesville

7 moths per/day. Corn is beginning to silk; 4-day spray schedule recommended.

June 11

Brookeville and Poolesville

Corn earworm traps set up

April 23

Freeze Damage

Corn’s growing point remains below the soil surface until the V6 stage. If corn had already emerged before the April 20–21 freeze, the plant should regrow even if the leaves were damaged or killed.

Corn Earworm Monitoring

We will deploy corn earworm traps in June.

The much-needed rain is causing issues with rot in some vegetables and low-growing fruit.

I have some rapid tests for tomato spotted wilt virus. If you suspect the virus is present in your fields and you would like to test, please call Kelly at 301-226-7954.

For current vegetable insect scouting tips, visit the University of Delaware's Weekly Crop Update. 

If you experienced crop or property damage from the April 20–21 freeze, please contact the Farm Service Agency (FSA) if you have not already done so.

FSA Phone: (301) 250‑4735 ext. 2

Weeds

• Virginia Tech Weed Identification

Insects

• Common Soybean Pests in Maryland
• Mid-Atlantic Guide to the Insect Pests and Beneficials of Corn, Soybean, and Small Grains

Diseases

Corn, Soybean, Small Grains, and Cucurbit Diseases, University of Delaware

Weather

• Maryland Mesonet

(A network of weather stations across the state, including three in Montgomery County)