The statement that is NOT a feature of glyphosate is (4) Inhibition of early steps in the biosynthesis of branched chain amino acids.

Explanation of each option

1. Little residual soil activity – True

• Glyphosate binds strongly to soil particles and is degraded microbially, so it shows limited residual activity and is mainly effective as a post‑emergence foliar herbicide.​

2. Ready translocation in phloem – True

• After foliar absorption, glyphosate is efficiently loaded into the phloem and moves from source leaves to sink tissues (meristems, roots, rhizomes), which underlies its strong systemic, broad‑spectrum control.​

3. Inhibition of a chloroplast enzyme catalyzing the synthesis of aromatic amino acids – True

• Glyphosate inhibits 5‑enolpyruvylshikimate‑3‑phosphate synthase (EPSPS) in the plastidial shikimate pathway, blocking biosynthesis of the aromatic amino acids phenylalanine, tyrosine, and tryptophan.​

4. Inhibition of early steps in the biosynthesis of branched chain amino acids – NOT a feature (correct option)

• Branched‑chain amino acids (valine, leucine, isoleucine) are targeted by other herbicides such as ALS/AHAS inhibitors.

• Glyphosate does not inhibit the branched‑chain pathway; its primary target is EPSPS in the aromatic amino acid pathway, so this statement is incorrect.

SEO‑oriented introduction (for article use)

Glyphosate is a widely used, systemic, post‑emergence herbicide that is rapidly translocated through the phloem and acts by inhibiting the plastidial EPSP synthase enzyme in the shikimate pathway, thereby blocking aromatic amino acid biosynthesis. It has relatively low residual activity in soil and does not target the branched‑chain amino acid pathway, making “inhibition of early steps in the biosynthesis of branched chain amino acids” the feature that glyphosate does not exhibit.