Pigeon pea is the often cross-pollinated crop but Alfalfa is the

Pigeon pea is the often cross-pollinated crop but Alfalfa is the Cross-pollinated crop.
In some crop plants, cross-pollination often exceeds 5 percent and may reach 30 percent. Such species are generally known as often cross-pollinated species.
Cross-pollination, also called allogamy occurs when pollen is delivered to a flower from a different plant.
Alfalfa, also called lucerne, is a perennial flowering plant in the legume family Fabaceae. Organic growers were concerned that GM alfalfa could cross-pollinate with their organic alfalfa, making their crops unsalable in countries that ban the growing of GM crops.
Pigeonpea is often cross-pollinated by bees (Megachile spp.). The level of cross-pollination between plants ranges from 0 - 40%, depending on genotype and insect pollinator populations.