ISSUE 10 July 3, 2002
CROP ROTATION RESTRICTIONS TO LENTILS
Rotation to lentils following application of Everest is 24 months. The ND Weed Guide indicates 11 months for edible legumes. This is correct for field pea and chick pea. However, rotation to lentils is 24 months.
Following Peak application, rotation to field pea is 10 months but 22 months for lentils and chickpea.
BROADLEAF/OTHER CROP HERBICIDE UPDATE - PART 2
Mode of action: Photosystem I inhibitor
a.i.: diquat- NH3 salt (2 lb ai/gallon)
Comments: Reglone has been used in Canada for several years and in 2000 will now become the U.S. standard formulation in the U.S. Same active ingredient as Diquat (diquat- dibromide salt). Labeled for preharvest desiccation of potato, alfalfa, clover, grain sorghum, and soybean seed crops.
Mode of action: ACCase inhibitor + photosynthetic inhibitor
a.i.: bentazon (Basagran) + sethoxydim (Poast)
Crops: Field pea
Comments: Federal registration approved as a supplemental label for use in dry pea. Labels can be accessed through CDMS.
Mode of action: EPSP synthase inhibition
Comments: - Some U.S. generic glyphosate = $18-20/gallon.
Glyphosate is available under the following labels:
1. 3 lb ae/gal ipa salt with full, partial or no adjuvant load.
2. 3 lb ae/gal (NH4)2 salt with full adjuvant load. - Touchdown 3
3. 3.7 lb ae/gal ipa salt with full adjuvant load. - Roundup UltraMax
4. 4 lb ae/gal ipa salt without adjuvants. - Several generics
5. 65% SG NH4 salt with full adjuvant load. (Roundup Ultra Dry)
- A supplemental label has been issued for preplant, preemergence, and at planting for flax.
- Supplemental labels are being developed for preharvest and spot treatment use in dry pea, lentil, and chickpea. Supplemental label for preharvest and spot treatment in dry edible bean in being considered.
- Studies in MN, NE, and KS confirm less weed control from application made after 6:00 pm until sunrise. Best control was observed when applied during daytime through full sunlight. IA seen similar results with Pursuit.
Mode of action: ALS inhibitor
Crops: Labeled in corn as Permit. Sandea = Dry beans, potato, veg crops.
Comments: Registration pending in dry beans, potato, and veg crops. Also labeled in turf as Manage. Excellent control of large-seeded broadleaf weeds. Will leave a residue in the soil - follow crop rotation restrictions. Longest carryover at pH 7. Rate of breakdown increases as pH increases or decreases from 7.
Mode of action: Mitotic inhibitor
Crops: Canola, crambe, and safflower
Comments: Federal registration has been approved for canola, crambe, and safflower nullifying any submitted Section 18 application. These federal registration resulted from contributions from IR-4, the Minnesota Canola Council, and Northern Canola Growers Association, and Leonard Shock, safflower grower at Vida, MT for the safflower registration.
Mode of action: Plant growth regulator
Crops: Registration on pasture/rangeland expected in 2003. Provides excellent common mallow control.
Comments: Tough will be discontinued after all existing supply has been sold. Section 24c registrations will be supported through 2004 for garbanzo beans (chickpeas) and mint in ND. Use of Tough on chickpea and mint are still required to sign indemnification agreements each year.
Valor 51DF (Valent)
Mode of action: PPO inhibitor - Cell membrane disruptor
Comments: Soil applied at 2 to 3 oz/A. Requires for 0.25 inch of rain for activation. Similar to Authority/ Spartan herbicide except no carryover. Research in alfalfa (established only), dry bean, field pea, mint, potato, onion and some vegetable crops are in development. Burndown will be allowed <30 days prior to planting wheat, corn, and sunflower. Provides E common mallow control also shows excellent algae control (on roofs). Shows white mold control in soybean. Very insoluble and absorption does not change with pH as sulfentrazone. Do not tankmix with acetamide (Dual, Outlook, etc.) herbicides.
a.i.: adjuvant recommended for all herbicides that require addition of an MSO or MSO + 28% nitrogen adjuvant system.
Comments: Available through AGSCO in 2002. A liquid multifunctional adjuvant composition. Recommended rate is 1 to 2% v/v. In most cases, 1% concentration is sufficient . Research shows additional nitrogen fertilizer is not needed. Concentration greater than 1% v/v is recommended in conditions are less than favorable for weed growth (very low air temperature and humidity, and tolerant weed species).
NDSU Extension Weed Specialist