Herbicide is just a category of pesticide. Pesticide is used to rid an area of unwanted pests while herbicide is used to get rid of unwanted plant life, like weeds, brush, unproductive bushes or trees, and other growth that takes nutrients away from crops and other useful plants. History shows that in industrialising countries in the past, including United States, Germany, Japan and South Korea, the same phenomena have occurred as workers have left agriculture and herbicides have been adopted. The objective of this research paper is to evaluate the relationship between use of herbicides and shortages of labour and cost effectiveness of herbicides in India after launching MGNREGA. Uses of herbicides are increasingly being adopted around the world as a substitute of weed management labour. Generally MGNREGA provides 100 day wage employment in a year to every rural household who is ready to do unskilled manual work. This unique feature of the programme has not only provides job to labour having no employment but also the labours working earlier in the agriculture fields. After coming of MGNREGA in 2006 Indian agriculture sector is suffering from two major problems that is shortage of labour and high wage rate. Therefore use of herbicides in India is being rapidly adopted. It is interesting to note that the real farm wages increased by 3.7 percent p.a. during 1990s compared to only 2.1 percent p.a. during 2000s and then rapidly rising by 6.8 percent p.a. during 2007-08 to 2011-12 in India. Due to MGNREGA raises the real wage rate of unskilled worker by 20 percent, create 70 million new work opportunities. FAO data shows that the use of herbicides has moved up from 2121.66 tonnes in the 2008 to 6334.98 tonnes in 2010. This shows use of herbicides has increased significantly after MGNREGA due to shortage of labour and cost effectiveness.