Weed Spotlight: Kochia (KOCHIA SCOPARIA)

Identification 

Kochia has a deep taproot, with an erect, highly branched stem that varies in colour from green to red. It has alternating, linear leaves and small, green flowers that lack petals and are found in clusters in the upper leaves. Kochia can grow up to 7 feet tall with competition, or show a more bushy appearance from 3 to 4 feet without competition.

 

Habitat

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Kochia is a highly adaptable summer annual broadleaf weed that has a wide tolerance for different soil types.1 It is very drought tolerant and can spread rapidly in dry conditions. Kochia populations resistant to many modes of action have been documented in many world areas. Resistance to ALS (Group 2) herbicides is widespread in Canada. Although resistance to synthetic auxins (Group 4) was confirmed in the United States, no cases of resistance have been found in Canada. Glyphosate resistant kochia has been confirmed in both the US and Western Canada.

 

Reproduction

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Kochia has wind-borne pollen and readily cross-pollinates. Seeds germinate in early spring because of their frost tolerance. Plants grow rapidly through spring and summer, sending their taproots up to 16 feet in depth. Kochia flowers and sets seed in late summer. Seeds are short-lived in the soil–up to three years, but mostly no more than one year. Seeds germinate at shallow depths.

 

Yield Loss

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The tumbleweed nature of kochia creates a distinct linear pattern of resistant plants in fields. A tumbling kochia plant can travel long distances, dropping seeds along the way, making it difficult for farmers to prevent kochia from entering their fields. In a Manitoba field study, at plant population densities of 195 plant/m2, kochia reduced spring wheat yield by 73%.2

 

How to Outsmart Kochia

  • Scout early and often.
  • Start clean and control kochia when it is small.
  • Always use two effective modes of action on the target weeds to help reduce resistance selection pressure.
  • Tillage is effective for kochia control.
  • Mowing or spot-tillage can be used on larger lines or patches before the plants go to seed.

 

 

Tank-Mix options for Kochia:

 

  

CORN HYBRIDS WITH ROUNDUP READY® 2 TECHNOLOGY

PP/PRE (tank mixed with Roundup Transorb® HC)

Dicamba, Heat® LQ

 

POST (tank mixed with Roundup WeatherMAX®)

​Armezon®, Dicamba, Distinct®

 

GENUITY® ROUNDUP READY 2 YIELD® SOYBEANS

 

PP/PRE (tank mixed with Roundup Transorb® HC)

Authority®, Authority® Charge, Heat LQ

 

POST (tank mixed with Roundup WeatherMAX®)

Viper® ADV

 

ROUNDUP READY 2 XTENDTM SOYBEANS

PP/PRE (tank mixed with Roundup Transorb® HC)
XtendiMax with VaporGrip Technology + Heat® LQ or Authority® or Authority® Charge

POST (tank mixed with Roundup WeatherMAX®)​
XtendiMax with VaporGrip Technology + Viper® ADV

GENUITY® ROUNDUP READY® CANOLA

 

PP/PRE (tank mixed with Roundup Transorb® HC)

CleanStart®, Conquer®, Pardner®

 

 

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Sources:
1 http://www.nwcb.wa.gov/detail.asp?weed=80
2 Friesen, L. F., Mayert, T. S. H. and Morrison, I. N. 1991. Control of sulfonylurea-susceptible kochia at two growth stages in spring wheat (Roblin). Res. Rep., Expert Committee on Weeds (West. Sect.). p. 442.