Hessian fly

See: Mayetiola destructor. Heteroecious

Greek = different houses. A heteroecious plant parasite is one that is compelled to parasitise two different species of host, often called the winter host, during which sexual recombination occurs, and the summer host, which involves asexual reproduction only, in order to complete its life cycle. A heteroecious pathosystem has two species of host. In practice, the only heteroecious parasites of plants are species of aphids and rusts, but some of them are major pests and disease of crops. During the summer phase, these parasites are r-strategists and a system of biochemical locks and keys, derived from the vertical subsystem and the gene-for-gene relationship, can be shown to have a remarkable evolutionary survival advantage. (See Self-OrganisingAgro-Eosystems, available as a sharebook on this website, for a more detailed discussion). Heterogeneous

Of different descent (c.f., heterogenous = of different composition). Pronounce it heterogeneous (c.f., heterogenous). See also: homogeneous, homogenous.

Growing Soilless

Growing Soilless

This is an easy-to-follow, step-by-step guide to growing organic, healthy vegetable, herbs and house plants without soil. Clearly illustrated with black and white line drawings, the book covers every aspect of home hydroponic gardening.

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