The most critical period for the weed competition in sugarcane is up to 4 months after sowing beyond which the crop smothers the weed flora by it self. Weed control in sugarcane is accomplished by adopting mechanical or chemical methods. Mechanical methods of weed control include cultural practices, hot weather ploughing, hoeing and weeding, mulching, cropping system etc. that reduce the weed population and increase the crop yield. But these methods are very cumbersome, time taking, expensive and at times it becomes of non-availability of labour and unfavourable climatic conditions for such operations. Mechanical methods can be practices effectively during the pre-monsoon period but their use during monsoon period is not very effective. Three to four interculturing are done as and when required.

Chemical weed control offers a good substitute of mechanical measures. Several herbicides have been tested for weed control in sugarcane.

1) Atrazine or Simazine @ 1.5-2.0 a.i./ha as pre-emergence (3-8 DAP)
2) Diuron or Alachlor or Tafazine @ 2.0 kg a.i./ha as pre-emergence (3-8 DAP)
3) Basalin @ 1.0-1.2 kg a.i./ha as pre-planting
4) Sincore (Metribuzine) or 2-4-D sodium salt @ 2.0 kg a.i./ha and 1.5 kg a.i./ha in 600 litres of water should be sprayed uniformly on the soil surface before emergence of eye buds i.e.10 to 15 days after planting. In addition to this, hand weeding should be done to remove weeds within the lines of cane as and when required.

Farmers of south Saurashtra are advised to cover the crop with sugarcane trash mulch (patari) @ 5 t/ha. If there is a shortage of sugarcane trash (patari), application of atrazine @ 2.0 kg/ha as pre-emergence followed by application of 2,4-D (sodium salt) @ 1.0 kg/ha at 60-70 days of planting should be sprayed or the crop should be kept weed free up to tillering stage.

Farmers of south Gujarat heavy rainfall areas are advised to carry out hand weding 2-3 times at an interval of 30 days along with the interculturing. In shortage of labour, application of atrazine and 2,4-D (sodium salt) or metribuzin @ 1.0 kg/ha as pre-emergence is also found effective for controlling the weeds.

Farmers of south Gujarat heavy rainfall areas are advised to spray atrazine @ 2.0 kg/ha as pre-emergence (3-4 days after sowing) followed by application of 2,4-D (sodium salt) @ 1.0 kg/ha at 8-10 days after planting or only atrazine @ 2.0 kg/ha as pre-emergence (3-4 days of planting) or 2,4-D (sodium salt) @ 1.0 kg/ha + paraquate @ 0.5 kg a.i./ha after three and six weeks of planting for effective control of weeds.

Hoeing and earthing are closely associated factors because hoeing is necessary for earthing. The hoeing is done with the help of savel or ccultivators and it just starts after one week of planting.(the first hoeing is called blind hoeing) and second about 3 weeks after sowing and subsequent hoeing after very irrigation. The objectives of blind hoeing are i) to break the hard crust at surface which might create problems to the sprouting seedlings, ii) to cover the exposed seedlings properly, iii) to up root the weeds, iv) to replace the damaged setts by diseases and pests. In all, the crop needs about 4-6 hoeing. The hoeings are necessary for better aeration,to check the loss of water through evaporation, better tillering, control of weed, insects and diseases. Earthing is done to protect the crop from lodging, facilitate irrigation and economize water use efficiency, to control weed infestation in the field, to remove the water shoots and drain out the excess water from the field. Earthing up is done at 2.5 to 3 months after planting with the help of ridger.