Control of weeds in maize and wheat – Part 7: White goosefoot

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    Young white goosefoot.
    Mature white goosefoot and green goosefoot (insert).

     

    Flower axillaries with shine black seed (insert).
    Soft white hairy appearance of leaves and red-purple colour of stems.

     

     

    Scientific name: Chenopodium album
    Afrikaans name: Withondebossie, bloubossie, hondepisbossie, seepbossie of varkbossie
    English name: White goosefoot, fat hen, wild spinach

    Short description

    White goosefoot is an annual, multi-branched, erect herb that can grow as tall as 1,5 m. This weed has a sturdy taproot and the stems are ribbed, green-yellowish, often reddish striped and hairless.

    The leaves are simple, alternately arranged and vary from lancet-shaped to egg-shaped. The leaf margins can be entire or irregularly toothed and are dark green at the top and floury white below.

    Seedlings can appear woolly due to the white colouring of the young leaves. Leaves can be 5 cm long and 3 cm wide. The flowers of Chenopodium are green in thick self-standing axillary plumes, with no crown and five keeled calyx leaves. The seeds are lenticular, black and shiny and up to 1,5 mm in diameter.

    Distribution

    This weed is commonly referred to as ‘morog’ or pigweed, but this weed must not be confused with Amaranthus species which are also edible. Chenopodium is widespread in South Africa, is frost tolerant and occurs regularly in winter crops.

    Control

    Cultivation
    Chenopodium can be controlled through shallow cultivation at the seedling stage.

    Chemically
    The most effective way to control this weed is by using herbicides. Several herbicides are registered for use on this weed in maize and wheat (Table 1 and Table 2). Follow the instructions and dosage recommendations on the label carefully. Be aware that green goosefoot is also a Chenopodium spp. (C. carinatum) and while most of the herbicides listed in Table 1 and Table 2 will also control green goosefoot, it is still necessary to make sure which Chenopodium spp. is indicated on the herbicide label. Always contact a reliable chemical advisor before using any chemicals to ensure the correct doses and specifications on the label are adhered to. All herbicides registered for the control of weeds are summarised in the publication A guide to the chemical control of weeds in South Africa. A CropLife South Africa Compendium.

    TABLE 1: Broadleaf herbicides registered on maize to control white goosefoot.

    Active ingredient Formula Time of application
    2,4-D480 g/litre

    Post-emergence when crop is 30 cm tall or apply as directed spray

    2,4-D/dicamba240/80 g/litre

    Post-emergence on actively growing weeds, five to six leaf stages

    acetochlor/atrazine/simazine160/165/165 g/litre

    Pre-emergence at, or just after planting

    acetochlor/atrazine/terbuthylazine125/187,5/87,5 g/litre

    150/225/225 g/litre

    178,6/160,7/160,7 g/litre

    200/150/150 g/litre

    250/225/225 g/litre

    350/175/175 g/litre
    Pre-emergence at planting, or within three days after planting

    Early post-emergence, not later than fourth leaf stage of weed
    alachlor/atrazine

    336/144 g/litrePre-emergence at planting or within two days after planting. Some products should not be applied on sandy soils with a clay content of less than 16%
    atrazine

    500 g/litre

    900 g/kg
    Pre-emergence on well prepared seedbed
    Early post-emergence, not later than two leaf stage of weed
    atrazine/cyanazine

    167/333 g/litre

    250/250 g/litre
    Pre-emergence or early post-emergence
    atrazine/mesotrione/s-metolachlor

    208,5/26,8/208,5 g/litrePre-emergence application
    atrazine/metazachlor/terbuthylazine

    210/60/210 g/litrePre-emergence within three days after planting. Can be followed-up with an early post-emergence application
    atrazine/metolachlor

    300/300 g/litrePre-emergence within three days after planting
    atrazine/metolachlor/terbuthylazine

    174/252/174 g/litre

    262,5/175/262,5 g/litre
    Pre-emergence or early post-emergence before the fourth leaf stage of weed
    atrazine/s-metolachlor

    370/290 g/litrePre-emergence just after planting
    atrazine/s-metolachlor/terbuthylazine

    248,6/102,8/248,6 g/litre
    Pre-emergence
    atrazine/sulcotrione

    300/125 g/litre
    Pre- or post-emergenc
    atrazine/terbuthylazine

    250/250 g/litre

    270/270 g/litre

    300/300 g/litre

    450/450 g/kg
    Pre-emergence or post-emergence before fourth leaf stage of weed

    atrazine/terbutryn


    250/250 g/litre
    Pre-emergence at planting or just after planting

    bendioxide

    480 g/litrePost-emergence
    bromoxynil

    225 g/litre

    400 g/litre

    450 g/litre

    500 g/litre
    Post-emergence of weed between four and six leaf stage
    bromoxynil/terbuthylazine

    150/333 g/litrePost-emergence
    dicamba

    480 g/litre

    700 g/kg
    Post-emergence when crop is 30 cm tall
    dicamba/topramezone

    160/50 g/litreEarly post-emergence before six leaf stage of weed. Apply in tank mix with atrazine or atrazine/terbuthylazi
    EPTC

    720 g/litrePre-plant incorporated into the soil. See product label for application specifications
    MCPA

    700 g/kg

    400 g/litre
    Pre-emergence within five to six days after planting

    Post-emergence up until crop is 30 cm tall
    mesotrione

    480 g/litrePre- or post-emergence. Apply in tank mix with atrazine, atrazine/terbuthylazine or s-metolachlor
    mesotrione/s-metolachlo83,3/416,7 g/litre
    Pre-emergence
    s-metolachlor/terbuthylazine
    102,8/497,2 g/litre
    Pre-emergence
    metribuzine480 g/litre

    Post-emergence between four and six leaf stage of weed in tank mix with 2,4-D or bromoxynil
    terbuthylazine
    500 g/litre
    Post-emergence of weed in tank mix with 2,4-D/dicamba

    topramezone
    336 g/litre
    Early post-emergence before six leaf stage of weed. Apply in tank mix with atrazine or atrazine/terbuthylazine

    Note: Some grass herbicides such as acetochlor, s-metolachlor, alachlor and s-dimethenamid can be applied pre-emergence in maize to control white goosefoot. Glyphosate can be applied post-emergence where
    glyphosate-resistant maize cultivars have been planted.

    TABLE 2: Broadleaf herbicides registered on wheat to control white goosefoot.

    Active ingredient Formula Time of application
    2,4-D

    480 g/litre

    500 g/litre
    Post-emergence when crop is between growth stage seven and 13. Apply only in summer rainfall regions (not in KwaZulu-Natal)
    bendioxide480 g/litrePost-emergence on actively growing weed seedlings
    bromoxynil225 g/litre

    400 g/litre

    450 g/litre

    500 g/litre
    Post-emergence where weeds are fully germinated and not older than six leaf stage

    Post-emergence when wheat is between the third and end of stooling growth stage

    Post-emergence where weeds are fully germinated and not older than six leaf stage

    Wheat should be between third leaf and booting growth stage
    bromoxynil/pyrasulfotole

    210/37,5 g/litrePost-emergence in winter rainfall region when weed is between four and six leaf stage
    carfentrazone-ethyl/

    metsulfuron-methyl
    400/100 g/kg
    Post-emergence in the Western, Southern and Eastern Cape Provinces when wheat is between three to five leaf growth stages
    chlorsulfuron750 g/kgPost-emergence when wheat is between two to five leaf growth stage
    chlorsulfuron/metsulfuron-

    methyl/tribenuron-methyl
    119/79/222 g/kgPost-emergence in the Western, Southern and Eastern Cape Provinces when wheat is between four to six leaf growth stages
    dicamba700 g/kgPost-emergence only in tank mix with Enhancer (10 g - 12 g) + Reaper (10 g) + adjuvant
    diflufenican

    500 g/litrePost-emergence only in winter rainfall region when wheat has been established. Read product label for specifications on application
    florasulam/flumetsulam

    75/100 g/litrePost-emergence only in winter rainfall regions. Apply when wheat is between second leaf stage and before end of tilling. Weeds should be in seedling stage
    iodosulfuron-methylsodium/

    mefenpyr-diethyl
    50/150 g/kgPost-emergence only in winter rainfall regions, before fourth leaf stage of weed or 3 cm tall
    iodosulfuron-

    methylsodium/metsulfuron-

    methyl/mefenpyr-diethyl
    30/30/90 g/kgPost-emergence only in winter rainfall regions, before the fourth leaf stage of weeds or 3 cm tall
    MCPA400 g/litre

    700 g/kg
    Post-emergence when wheat is between seven to 13 growth stage

    Mainly annual broadleaf weeds in dry land wheat
    metsulfuron-methyl/

    thifensulfuron-methyl
    68/680 g/kgPost-emergence when weed is between fourth to fifth leaf stage
    metsulfuron methyl/

    tribenuron methyl
    80/300 g/kg

    120/600 g/kg

    200 g/kg
    Post-emergence in the Western and Southern Cape Provinces when wheat is between four to six leaf stage. Apply only in tank mix with 2,4-D ester or Voloxynil B 225 EC
    metsulfuron-methyl500 g/kg

    600 g/kg
    Post-emergence only in winter rainfall regions when wheat is between three and five leaf stage
    prosulfuron750 g/kgPost-emergence when weed is between four and five leaf stage
    pyraflufen-ethyl20 g/litrePost-emergence only in winter rainfall regions when weeds are between two to four leaf stage. Apply in tank mix with MCPA and bromoxynil
    thifensulfuron-methyl750 g/kg

    Post-emergence in Western, Southern, Eastern Cape Provinces in tank mix with Enhancer and adjuvant. Wheat should be between two and five leaf stage and not later than four weeks after weed emergence
    triasulfuron

    750 g/kgApply at planting in the Western and Eastern Cape Province regions
    tribenuron-methyl

    750 g/kgPost-emergence only in winter rainfall regions and irrigated wheat in summer rainfall regions when wheat is between three and fifth leaf stage
    trifluralin480 g/litreOnly use in planted fields. Read label

    Contact the writers at elbe.hugo@syngenta.com (Elbe Hugo) and, deweth@arc.agric.za (Hestia Nienaber).