31. Chemical controls can include a variety of compounds.32. Chemical control is an option for practitioners who need to maintain high quality, visually pleasing turfgrass.33. Chemical control of the invasive plants, along with reintroduction of native species, have had some success.34. Chemical control of ground cover is advised.35. Using cultural control before chemical control can reduce detrimental effects to the ecosystem surrounding the growing environment. 36. The aster yellows index ( AYI ) can be used to determine when to apply chemical controls . 37. The disease is controlled mainly through genetic resistance, chemical control , crop rotation, and strategic timing of planting. 38. Chemical control of toadflax can be difficult.39. Chemical control of the pest is difficult.40. It reduces the spread of the plants in areas where mechanical and chemical control is not practical.
