Broadleaf Weed Management a Component of Integrated X-disease Management

To reduce the risk of transmission, removal of infected trees is key. It is also important to suppress or manage weeds present in your orchards, because the leafhoppers are attracted to the weeds, which they like to feed on.

X-disease phytoplasma infects most Prunus species, ex. cherries, peaches, nectarines, almonds, plums, and chokecherry. X-disease phytoplasma also infects a wide range of broadleaf plants. Previous work found dandelion, knotweed, goosefoot (lambsquarter), sagebrush, chickweed, mallow, alfalfa, puncture vine, tumble mustard, and flixweed were hosts (Jensen 1971). In a 2021 to 2023 survey 52 of 77 species tested were positive for X-disease phytoplasma (Harper et al in prep). Plants from six families had significant numbers of positives including members of the Asteraceae (dandelion), Malvacea (mallow), Amaranthaceae (goosefoot/ lambsquarter & pigweed), Polygonaceae (knotweed), Brassicaceae (flixweed, tumblemustard, hoary bittercress, & shepherd’s purse), and Plantaginaceae (plantain). See full list.

Grass

Planting grass in drive rows can reduce peak leafhopper numbers by approximately 50% compared to weedy drive rows (Northfield unpublished 2023). Leafhoppers cannot survive on grasses (Northfield and Cooper 2020).

Herbicide

Broadleaf-specific herbicide applications applied to the drive row can reduce leafhopper vector numbers by up to 50%, likely by reducing the preferred habitat for the leafhoppers (Northfield unpublished data). Time one spring broadleaf weed spray when weeds are small and before they develop seeds. A spring root sucker spray and a fall weed spray is another option. Pre-emergent herbicides for example pendimethalin (Prowl H20), norflurazon (Solicam DF) and residual herbicides for example indaziflam (Alion), rimsulfuron (Matrix SG), penoxsulam (Pindar GT), and post emergence herbicides for example pyraflufen-ethyl (eg. Venue), glyphosate (eg. Roundup Powermax), clopyralid (eg. Stinger, Agristar Spur), and glufosinate-ammonium (eg. Rely 280) are labeled for cherry tree rows. In addition to the tree row area generally targeted for weed management, consider herbicide applications that reduce broadleaf weeds in the grass strip using products that won’t kill grasses for example clopyralid (eg. Stinger, Agristar Spur) and pyraflufen-ethyl (eg. Venue). Watch your preharvest intervals.

Additional information

X-disease webpage

Alternative weedy hosts for X-disease phytoplasma

Little Cherry Virus webpage

Symptoms Gallery

X-disease Vector Gallery

Nursery Prevention of X-disease Phytoplasma and Little Cherry Virus Recommendations

BMPs for tree removal for X-disease and Little Cherry Virus infected trees

Case studies on tree removal for X-disease phytoplasma and Little cherry virus

Videos

Symptoms of Little Cherry Virus and X-disease Phytoplasma.

Síntomas de Fitoplasma X y Little Cherry Virus.

Symptoms of X-disease Phytoplasma in Stone Fruit.

Síntomas de Fitoplasma X en Frutas de Hueso.

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Perennial weed alternative hosts for X-disease phytoplasma

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Annual weed alternative hosts for X-disease phytoplasma

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Contacts

 

 

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