Pistachio > Year-Round IPM Program > Fruit development > Survey for Weeds: Late spring

Pistachio

Survey for weeds: Late spring

By surveying weeds in late spring, you can identify species that escaped earlier control efforts, and you will know which perennials are present and which summer annuals are emerging. It is possible that you will find winter annuals, summer annuals, and perennial weeds in various stages. If herbicides were used, this information will help determine the need to use different herbicides.

Manage weeds in tree rows. Annual weeds in row middles may be beneficial, but before shaking, manage weeds to provide a clean and smooth orchard floor.

Record your weed observations in order to make weed management decisions. Keep these records so that you can track weed species and numbers from year to year to better understand ongoing weed control problems such as resistance, and to determine how effective your management operations have been over the long term.

How to survey your orchards

• Survey in late spring or early summer, after summer annuals have germinated.
• If using cultivation, monitor at least 2 weeks before cultivating.
• If using preemergence herbicides, identify species not controlled.
• Check the ground cover in row middles for perennial seedlings. Check for regrowth of perennials a few weeks after cultivation.
• Sketch a diagram of the orchard and mark areas where perennials or other problematic weeds are found.
• Indicate the growth stage of the weeds on the form (seedling or mature).
• Rate infestation either using a numeric scale from 1 to 5 (1 being the lightest and 5 being the heaviest), or using "light," "medium," or "heavy."
• Record your results on a weed survey form.

Important links

• Photos of summer annual weed seedlings
• Photos of perennial weed seedlings
• Example weed survey form (PDF)
• Weed Management in Established Orchards

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