Mark VanGessel, Extension Weed Specialist; mjv@udel.edu
Delaware Department of Agriculture and MANA (Makhteshim Agan of North America) have approved a state label (24c) for use of Glory herbicide for winter wheat and barley. The active ingredient is metribuzin, formulated as a 75% DF. GLORY herbicide was requested for control of ALS-resistant chickweed. Glory is the only formulation of metribuzin with this special label in DE.
In addition to common chickweed, UD Weed Science has also had encouraging results with control of corn speedwell, henbit, and knawel when applied to weeds 3 inches or less. Injury has been a concern with metribuzin so we looked at metribuzin applied in the fall and two timings in the spring. Early-spring (early-March) applications caused some leaf burn on certain varieties, but injury was transient and no yield reduction was observed in three years of our trials. Late spring applications (first week of April) caused leaf burn, as well as some stunting and reduced yields in one of the three years.
Application timing is from 2 leaf stage of the small grain until jointing; and rate is dependent on crop stage, refer to label.
GLORY may be tank mixed with Axial, Harmony, Harmony Extra, 2,4-D, MCPA, Banvel/Clarity, Osprey, or Powerflex herbicides. A nonionic surfactant containing at least 80% active ingredient may be used in GLORY tank mixes. Do not use a crop oil concentrate or methylated seed oil (MSO) or any adjuvant containing vegetable or petroleum oils as crop injury may result. Use only water as the carrier, do not apply in nitrogen.
Precautions from the Glory label:
- Do not use on soils containing less than 0.75% organic matter.
- On irrigated cereals, do not apply more than 0.5 inch of water for the first irrigation. The maximum amount for each additional irrigation should not exceed 1 inch. Allow a minimum of 14 days between the first irrigation and subsequent irrigations.
Risk of crop injury can increase when applications are made:
- when the crop is under stress such as winterkill, frost damage, disease, drought or excessive moisture, severe grazing, or when these conditions follow the application;
- in combination with fluid fertilizer especially with the addition of surfactant;
- prior to the growth stage specified on this label;
- to soils high in lime or sodium, a pH greater than 7.7, calcareous, gravelly, thinly covered, or exposed subsoil areas;
- to fields where cereal seeds have been planted less than 1 inch deep;
- to a sensitive wheat or barley variety; and
- to frozen soil or crop still in winter dormancy.
Crop rotations range from 4 to 18 months. Refer to the label for rotations.