More is known about treating Bartlett pears than d’Anjous, Bosc, or other varieties, says ­Welcome Sauer, president of AgroFresh, which markets SmartFresh. In general: • MCP-treated pears sold earlier in the season take longer to ripen. • Pears stored longer ripen more quickly. • Treated pears stored in CA ripen more slowly ­afterwards. • Pears treated with MCP too early might not respond well. • Pears treated too late might be past the response zone. • Every variety acts differently to MCP in every region of the world.