"Today, I have taken the steps to remove sales of non-organic t-shirts and other products that damage the Earth from my concerts and my web stores," singer Neil Young writes on his website. "I vow to speak up and to do what I can to protect Earth." He has urged his fans to boycott accordingly.

Cotton is second for most pesticide use of all crops and uses 25% of all of the petrochemical based pesticides, fungicides and herbicides globally, argues the Canadian rocker.

"The Environmental Protection Agency considers seven of the top 15 pesticides used on cotton in the United States as 'possible,' 'likely,' 'probable,' or 'known' human carcinogens, " he writes.

"These chemicals absorb into the soil which can affect nearby crops, get into water supplies and rivers and affect many lifeforms downstream."

Young is along-time environmentalist, and recently announced his collaboration with Rainforest Connection. He helped to found Farm Aid and promoted his LincVolt electric car at another point in a long career as activist.

He will be headlining Farm Aid, along with Jack White, Willie Nelson, John Mellencamp and Dave Matthews, on September 13 in Raleigh, North Carolina.