Suminter focuses on organic produce for the textile and food industries.
"We had been looking to invest in clean technology and related sectors for some time, and we liked the entrepreneur (of Suminter)," Nexus India capital's Managing Director Sandeep Singhal said in a statement issued in Mumbai.
The investment amount was, however, not mentioned by the company.
Nexus typically invests around USD 2-5 million (Rs 8-20 crore) in a company and this is its fourth deal this year.
Suminter, which supplies to buyers in the US and Europe, currently has a farmer network in four Indian states, across 25,000 acres of land, that grow cotton, oil seeds, spices and herbs, as per the buyers' demand, the statement said.
The company works on a buy-back arrangement in which it pays farmers a premium, typically 10-15 per cent over the market price.
The harvest is processed and packaged at a central unit and then shipped overseas. It exports directly to the US and through a Netherlands-based subsidiary in Europe.