He told visitors to last week's Royal Show: "We grow crops for people, not bugs and birds, and we must protect them in a safe way."
He spoke after criticism from growers that the current pesticides regime was too tight and threatened to reduce yields. "Banning a pesticide in use at the moment without a viable alternative is something we are concerned about," he said. "We cannot afford to have yields reduced by 20 to 30 per cent - that's preposterous."
Rooker said bringing a pesticide or herbicide through the regulatory framework to market took years and cost millions of pounds.
"We have world-leading centres and it's not in our interest to damage them, any more than it's in their interest to produce unsafe chemicals. We need a positive approach."
He added: "We are radical and we want reform, but it must be reasonable and cost-effective so we don't snuff people out of business on a hunch or a whim or on political correctness."
However, he said the Pesticides Safety Directorate was world class and attracted foreign producers keen to benefit from the selling power that UK registration bestowed.
"We are not here to attack growers. The quality of our food is world class and we have more regulation than the rest of the world. We don't have to apologise to anybody."