NovaSource Crop Protection


Tessenderlo Kerley Inc Logo

In 2005 Tessenderlo Kerley, Inc. formed, NovaSource, a business unit dedicated to manage and develop their crop protection business.

Tessenderlo Kerley, Inc. is part of Tessenderlo Group, founded in 1919 and the descendent of The Kerley Chemical Company, founded in 1947 by four brothers who recognized a growing demand for sulfur plant nutrition in Pecos, Texas, shortly after the end of World War II.

The Kerley Brothers developed a unique process for manufacturing sulfur-based liquid fertilizers that are safe, easy to handle and can be applied through irrigation equipment.

In the early 1950s, Kerley Chemical opened retail stores and began selling fertilizers to farmers, retailers and distributors throughout the western United States and midwestern corn belt.

Acquisitions, ownership changes and growth guided the company through the years, while Tessenderlo Kerley established itself as a leader in the production and marketing of specialty products used in the agriculture, mining and process chemical industries. Tessenderlo Kerley is now the world’s largest producer of sulfur-based thiosulfate fertilizers.

For over 100 years, Tessenderlo Kerley, Inc. has demonstrated its commitment to agriculture through innovation, research and the development of sustainable crop protection products. 

NovaSource Product Expansion Through Acquisitions

Tessenderlo Kerley, Inc. acquired established crop protection products for the NovaSource portfolio so growers can continue to benefit from them.


Tessenderlo Kerley, Inc. acquires the global norflurazon (Solicam®) assets from Syngenta LLC. as well as DuPont's global hexazinone product and its hexazinone/diuron-only mixture. This resulted in NovaSource expanding their portfolio to include: Velpar®, Pronone® and Advance® trademarks, excluding assets in Brazil.


Tessenderlo Kerley, Inc. acquires the global carbaryl business for agricultural markets (Sevin®) from Bayer Crop Science


Tessenderlo Kerley, Inc. reaches agreement with Purfresh® and acquires Purshade®


Tessenderlo Kerley, Inc. acquires the global linuron (Lorox®, Linex®, LayBy Pro) business from Dupont


Tessenderlo Kerley, Inc. acquires the global terbacil (Sinbar®) business from Dupont and the global Surround® Crop Protectant business from BASF


Tessenderlo Kerley, Inc. obtains registration for metam potassium and introduces Sectagon® K-54. NovaSource introduces a portfolio of fosetyl-Al based fungicides in the ag, turf and ornamental markets in the USA