An overview of the various management practices that can be followed to control weeds in Triticum aestivum.

1. Weed Management in Wheat
SUBMITTED BY: AKASH SINGH SOARES (A-2014-01-005)
SUBMITTED TO: DR. M. C. RANA

2. Introduction
I. Major weeds in winter grain crops in India are Board leaved weeds
like Lamba quarters (Chenopodium sp.) Wild safflower (Carthomus
osycantha). In some parts of the country, perennial dicot weeds
viz. Canada thistle (Cirsium arvenses), Field Bind weed (Convalvulus
arvenses) are found.
II. Annual Grasses like Wild Oat (Avena fatua), Canary grass (Phylaris
minor). Due to weeds competition, many tillers wither before earing
stage. Ears get shortened due to prolonged competition, less number
of grains/ear and less weight of grains. The weed seeds get admixture
in the crop seed and reduce grain quality.

3. a. Mechanical Interculturing
Mechanical interculturing are not possible due to loss row
spacing. Hence practices like proper seed bed management. Use of clan
and high viability seeds crop rotation etc. are useful. One to two hand
weddings control simple annual weeds to boost crop production.
b. Herbicidal Control of Weeds
2, 4-D and MCPA are the most widely used herbicides, to control weeds
in wheat, oat and barley. 25 to 30 days age sage is sensitive to 2.4-D (rot
primordial). Rate at fully tillered stage is ½ to 1 kg a.i/ha.

4. c. Control of difficult annual Broad Leaf Weeds
Diuren and Limuren 0.5-1 kg/ha as pre and post emergence herbicides. A
mixture of Dicaba (0.125 to 0.250 kg/ha). Amine, 2,4-D 0.5 kg/ha) as
post emergence and Picehloram (0.30 to 0.42 kg/ha) as selective.
d. Control of Annual Grasses
Wild oat can be successfully controlled in wheat and barley by pre-
planting treatment of Diallate and Triallate and post emergence spray of
Barban Canary Grass : Nitrogen, tribunal, Limuron, Alachlor.
e. Control of Perennial Weeds
Bermuda grass (Cynodon dactylon), Dalapon or Amitrole /22 kg/ha pre-
planting paraquat 1 kg/ha. Pre-sowing 2 weeks before shallow summer
tillage and Attrazine. Spot treatment with MSMA, DSMA also controls it.

5. The wheat crop suffers badly due to heavy weed infestation. Phalaris minor Retz.,
Chenopodium albam L., Avena fatua L., Melilotus alba Deser., Melilotus indica All.,
Anagallis arvensis L., Fumaria parviflora Lam. and Convolvulus arvensis L. are
common weeds of wheat in the Indian subcontinent. Besides handhoeing and manual
weeding, use of herbicides plays a lårge role in weed management. Minimum tillage
has some positive effects on soil. Pre‐emergence application of pendimethalin,
terbutryn, methabenzthiazuron, bifenox and oxyfluorfen renders excellent weed
control in wheat. Isoproturon, methabenzthiazuron, metoxuron, terbutryn,
tralkoxydim and fluroxypyr post‐emergence give effective weed kill. For Avena fatua L.
control, triallate, difenzoquat and diclofop‐methyl show promising results. Herbicide
mixtures give broad‐spectrum weed control. Integrated weed management performs
better. Wheat cultivars Sonalika, WH‐147, WH‐2009 and HD‐2329 are tolerant to
isoproturon. Moderately susceptible varieties are WH‐157, WH‐291, DWL‐5023 and
HD‐2285. All these cultivars show tolerance to pendimethalin. Wheat herbicides now
in use do not have residual persistence. In wheat cropping systems, pendimethalin and
isoproturon meet the basic requirements.