Dr. Ayanava MajumdarExtension Entomologist

Alabama Cooperative Extension SystemGulf Coast Research & Extension Center

8300 State Hwy 104, Fairhope, Alabama 36532Cell phone: 251-331-8416

PART 3A

Trap Cropping for

Sustainable Crop Production(discussion on key insect behavioral concepts)

Objectives

• To discuss basics of IPM• To help you identify & use cultural control

tactics• To make a strong case for trap cropping (using

published scientific literature)• Discuss some basics of insect behavior• Provide general trap cropping guidelines

Point to Ponder: What is Integrated Pest Management (IPM)?

• IPM is an effective and environmentally sensitive approach to pest management that relies on a combination of common-sense practices.

• IPM programs use current, comprehensive information on the life cycles of pests and their interaction with the environment.

• IPM takes advantage of all appropriate pest management options including, but not limited to, the judicious use of pesticides.

• Organic food production applies many of the same concepts as IPM but limits the use of pesticides to those that are produced from natural sources, as opposed to synthetic chemicals.

Source: USEPA http://www.epa.gov/pesticides/factsheets/ipm.htm

Premise for using cultural pest control strategies

• Set action thresholds: “Sighting a single pest does not always mean control is needed.” Think in economic terms!

• Monitor and Identify Pests: “…monitoring and identification removes the possibility that pesticides will be used when they are not really needed...”

• Prevention: “…using cultural methods…that can be very effective and cost-efficient and present little to no risk to people or the environment.”

• Control: “Effective, less risky pest controls are chosen first, including highly targeted chemicals, such as pheromones to disrupt pest mating, or mechanical control, such as trapping or weeding.”

Source: USEPA http://www.epa.gov/pesticides/factsheets/ipm.htm

USEPA’s Four-tiered Model of IPM

Multiple cropping for Diverse Habitat

Host plant quality hypo.: plant species can interact in a way to reduce attractiveness to pest (Theunissen 1994)

Pre-IPM Era (-1970s)Resource concentration hypo.: herbivores (=pests) remain in an area where essential resources are concentrated (Root 1973)

IPM Era (1970-1990s)

Natural enemies hypo. (Root 1973): cultural control tactics can conserve or increase natural enemies (Hummel et al. 2002, Peachey et al. 2002, Schmidt et al. 2004, Carmona & Landis 2003)

Diverse background moderates insect behavior (1960 – 1985): insects get confused or separated!

Post-IPM Era (1990-)

What is a trap cropping?

• Agronomic definition:– Trap cropping is the planting of an attractive trap crop

to protect the main crop (PAN Germany, 2009). Trap crop may or may not be harvestable.

• Entomological definition:– Trap cropping is a production system that exploits

insect behavior by continuously providing food plants in the preferred stage (Grossman 2008)

“Presence of second crop in the vicinity of principal crop diverts a pest, which would otherwise attack

the principal crop” (Van der meer 1981)

“Trap cropping is a special case of multiple cropping.”

Why should you use trap crops?

Corn earworm devastated sunflower (trap crop) but stayed away from peanuts

Image source: ICRISAT, India

Combined use of cultural control

+Insecticides =IPM approach

Trapcrop

New insecticide

Host finding & oviposition behaviorArrestants:

• Plant color, odor, shape (acts at a distance)

• Texture, phytochemicals, treatments (acts after landing)

Note: Adult females make the decision to oviposit &

starts a primary infestation!

How trap cropping works?Various behavioral theories that could explain success of trap crops.

1. Visual camouflage (Smith 1969)

2. Masking of host plant odor (Tahvanainen & Root 1972)

3. Resource concentration hypothesis (Root 1973)

4. Natural enemies hypothesis (Root 1973)

5. Physical obstruction (Perrin 1977)

6. Deterrent chemicals (Uvah & Caoker 1984)

7. Interplant interaction alters host quality (Theunissen 1994)

8. Impaired apparency of host plants to insects (Finch & Kienegger 1997)

9. Appropriate/inappropriate landings (Finch & Collier 2000)

Trap cropping arrangements

• Trap crop surrounds the main crop from all sides

• Feasible on small to medium scale

• Too resource-intensive on large scale (seed, time, management)

• Boucher et al. (2003): bell pepper/cherry peppers/pepper maggots

Perimeter Trap Cropping

Trap cropMAIN CROP

TRAP CROP

Trap cropping arrangements

• Dr. Sam Pair, USDA-ARS• Trap crop = early planted

squash, apply insecticide on borders

• Squash lured 66% cucumber beetles and 90% squash bugs

Perimeter Trap Cropping (contd.)

Main crop (watermelon, cantaloupe, cucumber)

Trap crop (squash)

Trap cropping arrangements

• Planting trap crop (alfalfa) in rows within the main crop (cotton)

Row Trap Cropping

Alfalfa

Cotton Cotton

Sustainable American Cotton Project, NCAT

Southern green stink bug

Trap cropping arrangements

Planting trap crop (alfalfa) in rows within the main crop (strawberry) & a using vacuum!

Row Trap Cropping (contd.)

Alfalfa

Strawberry(34 rows)

Strawberry(34 rows)

Strawberry production in California

Western tarnished plant bug damage

Trap cropping arrangementsStrip Trap Cropping

• Planting trap crops in a strip along one common border between two or more crops

• Tillman (2006): cotton/sorghum/southern green stink bug…integrated pheromone trap + trap crop

Also reported high parasitism rates from tachinid fly in sorghum

Trap cropping arrangementsStrip Trap Cropping (mechanism)

Sorghum(trap crop)

Cotton

Peanut (reservoir for pest)

Green stink bugs migration

Trap cropping arrangements

• Tillman (2006): IPM approach to stink bug control

Strip Trap Cropping (contd.)

Sorghum trap crop

Picture source: Agricultural Research Magazine, January 2008

Trap cropping systems

• Trap crop is highly attractive to the insect pest, but the trap crop does not support its growth & development.

• Diamondback moths are attracted to yellow rocket over cabbage, trick is:– Trap crop planted in higher densities (more eggs)– Trap crop planted earlier than main crop (increase attractiveness)

Dead-end Trap Cropping

(Shelton & Nault 2004, Badenez-Perez et al. 2004)

TRAP CROP MAIN CROP

NE Conservation System

• Grass shelters natural enemies

• Many night-feeding insects hide in grass during day…treat the edges!

• Sample in grass and keep it under control

Grassy buffers

Grassy buffer zone in

temporary agroecosystem

Grassy buffer zone in

permanent ecosystems

How multiple cropping/conservation systems affect natural enemies?

Increases spiders (Hummel et al. 2002), increase predatory mites (Peachey et al. 2002), maintains or increases ground predators (Schmidt et al. 2004, Carmona & Landis 2003)

Conserves ground-dwelling predators that regulate aphid population (Schmidt et al. 2004)

Conservation tillage improves soil persistence of insect pathogens (Hummel et al. 2002)

Advantages of trap cropping• Sustainable technology – literature review with numerous successful applications

• Suitable for commercial and noncommercial crop production

• Allows small startup without investing in large equipment

• May pay for itself if crop is harvestable (alfalfa, squash)

• Can be integrated with existing farming/gardening practices

• Reduces dependence on chemical pesticides

• Conserves indigenous natural enemies by providing shelter & continuity

• Knowledge intensive practice (like IPM)

• Need for additional planning (e.g., early planting), materials (e.g. seeds, land), and labor

• Trap crop recommendations are unique to the insect (behavior affects efficiency of trap crops)

• Results may be inconsistent (moderated by weather events)

• Proportion of cash crop: trap crop = 10%, 20%,?

• Timely management of insects in trap crop: problem if you miss!

Disadvantages of trap cropping

Recommendations for trap cropping• Try it on a small scale to gain confidence

• Integrate with biological/chemical i-cides, pheromone trapping, mass trapping, etc.

• Trap cropping is more management intensive!

• Trap cropping could manage one or two insect species

• Works great against sucking pests (plant bugs) and slow fliers (beetles)

• Could work against generalist feeders like lepidopteran moths (cutworms, diamondback moth, etc.)

Recommendations (contd.)

• Trap crop should be highly attractive to pest!

• Choose trap crops that have bushy growth habit (alfalfa, grasses, etc.) and/or large leaf area (squash, ornamental plants?)

• Proportion of land in traps (10-25%)…or choose per your observations & skills

• Plant a dense row of trap crop, plant early

• Choose a simple design – easy to manage

• Keep your main crop well irrigated, prevent plant competition

• Keep records and maintain a pest calendar

What insecticides can be used with trap crops?• May use the following

regularly and in rotation:

– Thuricide, Dipel (Bt)

– Novodor, Foil (Bt)

– M-pede (soap)

– Pyganic (pyrethrum)

– Pyrellin (pyrethrum + rotenone)

• Contact a nursery for supplies & purchase early

• Do not use unlabeled insecticides (e.g., RTU home pesticides)

Trap Cropping for

Sustainable Vegetable Production

QUESTIONS?

PART 3A