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GENERAL INSTRUCTIONS

Overwatch eXL Granules Herbicide is a soil-applied, preemergent herbicide that is absorbed by the roots and shoots of germinating plants. It is upwardly transported via the plant's xylem/transpiration system. The mode of action is through blocking carotenoid biosynthesis. After absorption, susceptible germinating plants are deprived of protective carotenoids, disrupting their ability to photosynthesize. Weed seedlings that have absorbed Overwatch eXL Granules commonly emerge with a bleached and/or purple appearance and rapidly desiccate over a few weeks as their seed energy store is depleted.

Apply prior to sowing and incorporate by sowing (IBS) with knife point tynes and press wheels (KPPW). Activity of Overwatch eXL Granules requires placement near germinating seeds, which is most consistently achieved by mechanical incorporation. Best results are achieved when applied to a moist soil profile, and sowing occurs soon after application. Weed control may be significantly reduced where there is insufficient soil moisture to mobilize the active for uptake by the germinating weed seedling, particularly if the weeds germinate from depth and there is sufficient moisture for sustained growth.

APPLICATION

Ensure complete and uniform spray coverage on the soil. Reduced effectiveness may occur where there is reduced contact of the herbicide with the soil surface. Spray coverage may be compromised where application is made to a ridged or excessively cloddy soil surface or where cover of crop or weed residues restricts contact with the soil surface. Efficacy may be unsatisfactory if ground cover is shielded by heavy stubble. For example, stubble can be observed in header rows where stubble and trash have not been distributed evenly. Stubble lying horizontally on the ground will have higher active ingredient interception than standing stubble. It is best to delay application to recently burnt paddocks or windrows until rainfall occurs to disturb the layer of ash, as Overwatch eXL Granules may be strongly adsorbed to ash, inhibiting passage through to the soil.

Application to paddocks with excessive stubble load (>50% ground coverage) may lead to increased levels of bleaching in the emerging crop. The level of weed control achieved by Overwatch eXL Granules depends on the positioning of weed seeds relative to the layer of treated soil. Weeds that germinate from deeper within the soil profile may escape due to a lack of herbicide-treated soil solution in that root zone.

GROUP 13 HERBICIDE

As with all pre-emergent herbicides, it is important that treated fields are constantly monitored for weed germinations throughout the season and treated with corrective post-emergent herbicides as required. Avoid holding Overwatch eXL Granules spray solutions overnight in equipment. If this occurs, ensure that the spray solution is vigorously agitated so that the product is thoroughly resuspended. In case of equipment breakdown, flush spray lines out and maintain agitation on the spray vessel to prevent settling.

SEED PLACEMENT & EQUIPMENT

Only apply prior to sowing at a minimum depth of 1.5 cm (canola) and 3 cm (all other crops) below the soil surface to minimize phytotoxicity to the emerging crop. Sowing with knife points and press wheels is regarded as the safest sowing configuration when using Overwatch eXL Granules. Crop safety when using disc seeding systems is variable based on seed placement and the influence of stubble, causing insufficient soil cover to the seed. Overwatch eXL Granules should be applied prior to sowing and incorporated by sowing using knife point and press-wheel equipment. Incorporation with a knife point and press-wheel may result in reduced weed control in the drill row. If using a knife point and press-wheel planter, adjust working speed to avoid excessive soil throw into the adjoining seeding row. Weeds germinating from depth, about to emerge, or emerged weeds not controlled by knockdown herbicides may not be controlled by Overwatch eXL Granules.

ENVIRONMENTAL CONDITIONS

Overwatch eXL Granules requires adequate soil moisture for effective weed control and is most effective when applied evenly to moist soils just before incorporation by sowing. Sufficient rainfall soon after application allows Overwatch eXL Granules to move with soil moisture into the weed's root zone, increasing uptake potential.

CROP SAFETY

For all crops, there may be some risk of interim crop phytotoxicity. In most situations, phytotoxicity is expressed as bleaching of the older leaves. The effect is transient, and generally localized as the new leaves emerge unaffected. Crop bleaching disappears, and there is no yield penalty. In serious cases of overdosing or unfavorable environmental conditions, phytotoxicity can also lead to stunting and a reduction in crop plant populations (or thinning). Incidences of elevated crop phytotoxicity may occur in several situations, including overlapping spray swaths, heavy rain, irrigation or strong wind soon after planting, high/heavy rainfall events in light soil types, and increased phytotoxicity due to crop stress.

SPRAY EQUIPMENT

Always ensure the sprayer is clean, using a suitable tank cleaner as directed. Defer to the most rigorous cleanout procedure if tank mixing with a partner. It is recommended that Overwatch eXL Granules be applied at least 80 L/ha and as a minimum coarse quality spray. The most preferred application regime for Overwatch eXL Granules involves the use of standard boom ground sprayers fitted with bypass or mechanical agitation, TeeJet TTI nozzles operated at between 3 and 5 bar, narrow nozzle spacing of 25–50 cm, a minimum application volume of 60 L water/ha on bare soil, a maximum travel speed of 20 km/h, and the minimum boom height that still ensures double overlap.

COMPATIBILITY

Overwatch eXL Granules is formulated as a water-dispersible granule and has been shown to be physically compatible with various herbicide active ingredients. When mixing Overwatch eXL Granules with other herbicides, it is essential to understand all risks associated with using other herbicides in a tank mix. Ensure that all precautions on the label of the tank mix partner are closely followed. A comprehensive physical compatibility guide for Overwatch eXL Granules is available online, from your Overwatch accredited agronomist, or from your point of purchase or local FMC representative. Always read the product label and any available technical advice for the manufacturer's tank mix recommendations and to determine individual product compatibility options and correct mixing orders for individual products. As tank mix partner formulations can vary substantially between manufacturers, and with the quality of spray tank water varying with location, all spray mixtures should be jar tested before mixing commercial quantities. Physical compatibility does not always guarantee biological compatibility and should be undertaken only with careful consideration.