Glean

Glean is a selective systemic herbicide developed by DuPont, containing the active ingredient Chlorsulfuron at a concentration of 750 g/kg, typically formulated as a water-dispersible granule or dry flowable. It belongs to the sulfonylurea chemical class, a family of herbicides discovered by George Levitt in 1975 that revolutionized agriculture due to their extremely low application rates and environmental safety profile. Glean is specifically recommended for use in wheat, barley, and oats, providing effective control of a wide range of broadleaf weeds both pre-emergence and post-emergence to the crop. It is intended for use on land with a soil pH of 7.5 or lower and is most effective when applied to actively growing weeds at rates as low as 10 to 20 grams per hectare, making it highly cost-effective. The product controls numerous troublesome weeds including wild mustard, shepherd's purse, lambsquarters, pigweed, velvetleaf, Canada thistle, chickweed, and cocklebur, among others.

How It Works
Glean works through systemic action, being absorbed by both the roots and foliage of target weeds and then translocated throughout the plant to the growing points in roots and shoots. Once inside the weed, the active ingredient chlorsulfuron inhibits the enzyme acetolactate synthase (ALS), also known as acetohydroxyacid synthase, which is essential for the production of branched-chain amino acids—valine, leucine, and isoleucine—that are vital for protein synthesis and plant growth. Research has demonstrated that this inhibition results in a rapid cessation of cell division within hours of application, reducing growth by up to 80 percent within eight hours, while initially leaving other processes like photosynthesis, respiration, and RNA synthesis unaffected. Without the ability to produce essential amino acids and divide cells, the weeds stop growing, gradually yellow, and eventually die, typically within one to three weeks depending on species and growing conditions. Because Glean is selective, it does not harm the cereal crops it is applied to, creating a safe environment for crop development while effectively eliminating competing weeds.