What does PCNB stand for?

PCNB stands for Pentachloronitrobenzene. This chemical compound is notable in agricultural practices, particularly as a fungicide used to control a variety of soil-borne diseases in crops. Its effectiveness arises from its ability to inhibit the growth of specific fungi, making it valuable for maintaining plant health and yield.

Understanding PCNB's role in seed treatments and broader agricultural contexts is critical for effective pest and disease management strategies. The other choices do not correspond to recognized acronyms or widely accepted terminology in the context of agricultural chemicals or treatments. This establishes Pentachloronitrobenzene as the correct identification of PCNB, linking it directly to its purpose and applications in agriculture.