Next time a grassy schoolyard in Connecticut starts going bald from an infestation of grubs or billbugs, or crabgrass starts to supplant the turf and clover, groundskeepers will have to put some new techniques to work to combat the problems.

Gone are the containers of synthetic pesticides like Merit and Roundup that used to be a fixture of school lawn care. As of July 1, a law banning the use of synthetic pesticides on lawns of preschools and kindergarten through eighth-grade schools took effect, five years after the original law was passed by the General Assembly.

The law was revised and its full enactment delayed several times, even as many districts had been reducing or even totally eliminating pesticide use. It finally slipped through in time for the start of the 2010-11 school year.

“I have been getting a lot of inquiries and a certain amount of frustration,” said Bradford Robinson, pesticide program supervisor for the state Department of Environmental Protection. One grounds manager called him last week to ask him how to get rid of the billbugs destroying a new field.