Major Weeds
Amaranthus viridis	Celosia argentena	Chloris barbata
Commelina benghalensis	Cyperus rotundus	Digitaria longiflora
Echinochloa sp	Euphorbia hirta	Phylanthus niruri
Trianthema portulacastrum

Weed Management:

Among the pulses, pigeonpea is only crop that has characteristically slow initial growth rate making it less competitive with weeds are not controlled in time.
           
In traditional production systems, intercropping is able to reduce weed infestation by 50 to 70 percent. Intercropping of maize and Sorghum can suppress weeds for longer period. With short season pigeonpea, fast growing cereals are unsuitable intercrops. However, low stature crops such as cowpea, greengram, blackgram, groundnut and soybean as smother crops can minimise the weed problem. Short season pigeonpea can take advantage of high plant density even when grown assole crop .
           
For short season pigeonpea, the first 30 days appear critical, although this period may vary with the genotype and time of sowing. One hand weeding at 45 DAS is not as effective as two weedings at 25 and 45 days after sowing. A number of herbicides have been found useful for pigeonpea systems. The following PRE herbicides are very effectiv in minimizing weed problem;

• Alachlor(1.0-1.5)
  
• Metolachlor(1.0-1.5)
  
• Pendimethalin(1.0-1.5)
  
• Oxadiazon(0.75-1.0)
  
• Prometryn(1.0)+ Fluchloralin (1.0)+ Paraquat(1.0)

Paraquat can be used to control weeds that have already germinated at the time of sowing. There may not be any toxic effect to crop even when paraquat is applied 4 days after sowing. It is common observation that herbicides are slightly inferior to hand weeding in pigeonpea. It is therefore, suggested to give a hand weeding at 40 to 45 days after sowing. It is common observation that herbicides are slightly inferior to hand weeding in pigeonpea. It is therefore, suggested to give a hand weeding at 40 to 45 days after sowing in herbicide applied fields. Marginal superiority of Oxadiazon and Pendimethalin herbicides has been indicated, since they are effectve for longer period than others recommended for weed control in pigeonpea.