Source: http://vasat.icrisat.org/crops/pearl_millet/pm_production/html/m10_2/ind...

Chemical control

The delay in manual weeding and intercultivation could be due to uncertain weather conditions. Therefore, chemical weed control has a place in pearl millet weed control strategy. Chemical control or herbicide application is advantageous in case of non-availability of labor and/or very high cost of labor for manual weeding. Use of correct herbicides will provide completely weed-free situation to the crop where as manual or mechanical weeding can be practiced only after the emergence of weeds. Use of chemicals (herbicides) to control weeds should be based on their comparative advantage over the manual and mechanical control of weeds.

Herbicide application requires some knowledge about the use of such chemicals. Improper use of herbicides may lead to the complete loss of the crop.

The farmers need to understand the proper use and application of herbicides before applying them to control weeds in pearl millet crop.Satisfactory control can be obtained by combining timely cultivation, crop rotation and herbicide applications. However, efficient and cost-effective weed control can be achieved by using combination of herbicides or combining manual and herbicide control methods.

Depending on the time of application, herbicides are grouped as:

• pre–planting (incorporated into the soil before sowing of the crop) herbicides,
• pre–emergence (after sowing but before emergence of seedling) herbicides,
• post–emergence (after emergence of weeds and the crop) herbicides.

Pre–sowing/planting (incorporated into the soil before sowing of the crop) application of herbicides.

Pre–emergence (after sowing but before emergence of seedling) application of herbicides.

Pre–emergence (after sowing but before emergence of seedling) application of herbicides.

Post–emergence (after emergence of weeds and the crop) application of herbicides.

Herbicides should be selected based on specific type of weeds (broad leaved or grass or sedge) encountered in a field, and also keeping in view the rotational crops followed after pearl millet harvest.

It is very difficult to control grassy weeds with post-emergence herbicides as pearl millet crop itself may be affected. So plan to use a pre-emergent herbicide if grassy weeds are expected. In general, herbicides like Atrazine, Propazine, Prometryne and Simazine are recommended for weed control in pearl millet. Atrazine usually gives better control of weeds than Propazine but Propazine was found to be safest.

If the field is weedy with annual grasses and broad leaved weeds before sowing pearl millet:

Spray Praquat (Gramoxone) on the weeds at 0.5 to 1.5 liters per ha depending on the weed density. Consult the product label prior to use.If the field is weedy with annual grasses and broad leaved weeds before sowing pearl millet: If sedges like Cyperus spp., Bermuda grass, Johnson grass,field bind weed dominate in the field, spray Glyphosate (Roundup) at 0.5 to 1 liter. Direct the spray on the weeds as Glyphosate becomes inactive in the soil. Consult the product label prior to use.

Pre-emergence application:

Atrazine or Propazine or Prometryne at 1.0 kg a.i./ha is recommended to control emerging weeds after the sowing of pearl millet. There should be optimum soil moisture at the time of application of Atrazine Application of Metalochlor 1 kg a.i./ha found to control the weeds effectively and increase the yield and net income of pearl millet intercropped with pulses like Cowpea / Black gram / Green gram (mungbean).

Post-emergence application:

Low rates of 2,4-D at 0.5 to 1.0 kg/ha may be applied when the plants are between 10 to 30 cm tall. Spraying later time affects yield by reducing seed set. Early treatment can also be injurious by damaging the root system.

    

 Abutilon indicum Indian Mallow                          Abutilon indicum

                    Alysicarpus sp. One-leaf clover

              Argemone mexicana Mexican poppy

  

           Celosia argentina White cock's comb

Cleome sp. Wild spider flower

                   Digera arvensis Kundra

   

                        Corchorus olitorius Jew's mallow

      

 Euphorbia hirta Spurge                          Euphorbia purviflora

                     

Portulaca oleracea Common purslane                           Portulaca pilosa

                 

                               Vernonia cinerea Little iron weed