The Arizona Vegetable Integrated Pest Management Update (Part Two) from the University of Arizona (UA) Cooperative Extension in Yuma, Ariz. released Sept. 20, 2012.

Using the botanical classification of crops to evaluate herbicide tolerance

By Barry Tickes, UA Area Agriculture Agent

An increasingly diverse number of minor acreage specialty crops are grown in this low desert region every year. Managing some of these crops can be difficult without local experience.

Crops in the same family often have similar growth habits, pest problems, and fertility requirements. It can be helpful to know the botanical family.

There are few pesticides registered for these crops due to limited acreage but the response to pesticides is often, but not always, similar to that of other crops in the same family.

Kerb (pronamide), for example, is generally safe to crops in the composite family (lettuce, artichokes, radicchio, etc.) but is harmful to crops in the brassica family(broccoli, bok choy, etc.).

The question of Balan safety to endive came up this week. Prefar and Kerb are registered on this crop but not Balan. Endive is in the same botanical family as lettuce. This is the Aster, sunflower, or composite family. It is the largest family of flowering plants.

Endive is in a different genus, however, than lettuce. The genus is in the chichorium (chicory) genus while lettuce is in the lactuca genus. Escarole and radicchio are types of endive. It is unclear if Balan is not registered on endive due to crop safety or other registration issues.

Herbicides are sometimes unregistered on certain crops since required studies have not been completed and a tolerance has not been established.

We are currently evaluating the safety of Balan to endive and escarole and should have an indication in about a week.

Click the link to listen to Barry.

Contact Tickes: (928) 580-9902 or btickes@ag.arizona.edu.

What’ insects are out there at night on the farm? An update on black light trapping

By Ta-I Huang, UA post doc research associate

Black light trapping is an effective way to survey local insect diversity.

Our original intention was to monitor Bagrada bug activity and to see if the insect could be trapped using a black light system.

We set up three locations on the YAC farm: between a broccoli and cauliflower field; between a broccoli and bermudagrass field; and in a greenhouse where our Bagrada colony is located. We monitored using black lights for 12 hours overnight last weekend.

We observed no signs of the Bagrada bug attracted towards the wavelength produced by black lights. However, other closely relative stink bug species and Lygus plant bugs were found in few numbers.

The majority of the insects collected in our light trap were beetles. The rove beetles (Staphylinidae) and ant-like flower beetles (Anthicidae) constituted more than 90 percent of the beetle population.

Other common beetles collected include scarab beetles (Scarabaeidae), ground beetles (Carabidae), and darkling beetles (Tenebrionidae).

Crickets were extremely abundant in our light traps with several species collected, largely since the field selected for light trapping was not sprayed with insecticide.

Interestingly, day-time active flea beetles which show great numbers in untreated broccoli fields were not caught any in our light traps.

Although Bagrada bug and flea beetle cannot be attracted by black light, insecticide applications are still effective in reducing the populations. A broccoli field during stand establishment can be completely wiped out by the combination of Bagrada bug and flea beetle feeding if no chemicals are applied.

As the cole crop growing season carries on, more leafy tissues become available and loppers and other worms will be another challenge.

Monitoring of adult moth population at night using black lights will be helpful for determining increased activity, especially on organic farms.

Click the link to listen to Ta-I.

For more information, contact Huang at huang@cals.arizona.edu.