1,5-dimethyl-6-thioxo-3- (2,2,7-trifluoro-3-oxo-4- (prop-2-ynyl) -3,4-dihydro -2H- benzo [b] [1,4] oxazin-6-yl) -1,3,5-triazine-2,4-dione Form a

The present invention relates to 1,5-dimethyl-6-thioxo-3- (2,2,7-trifluoro-3-oxo-4- (prop-2-ynyl) -3,4-dihydro -2H- benzo [b] [1,4] oxazin-6-yl) -1,3,5-triazine-2,4-dione new crystalline form A. The present invention further relates to a method for producing the crystalline form and containing 1,5-dimethyl-6-thioxo-3- (2,2,7-trifluoro-3-oxo-4- (propan-2- the alkynyl) -3,4-dihydro -2H- benzo [b] [1,4] oxazin-6-yl) -1,3,5-triazine-2,4-dione - the new crystalline form of formulations for plant protection.