Dessicator

A glass jar with a air-tight lid that is used for drying out small quantities of plant tissue, such as seeds or root nodules. Dry calcium chloride is a powerful desiccating chemical, but it is toxic and must be kept well separated from living tissues. Alternatively, silica gel is harmless, but it is less powerful in its drying action. Determinate habit

The converse of the climbing habit in plants. A determinate plant remains relatively small and close to the ground, like dwarf beans or potatoes. The determinate habit results from the terminal flower of an inflorescence opening first, and the further lengthening of the stem is then arrested. Dew

See: Guttation. Diallel cross

A polycross in which each parent is mated with every other parent. In a full diallel cross, each parent is represented twice, once as a male and once as a female. More commonly, a half diallel cross is used, in which each parent is represented only once, either as a male or a female, but not both. A half diallel cross is usually used at the start of recurrent mass selection . The alternative is to use a random polycross. Dichotomous

A dichotomous stem is one that forks regularly into two branches. Dicotyledon

Any Angiosperm that has two cotyledons. They are often called the broad-leaved plants. Seeds of dicotyledons can be split into two halves (e.g., split peas) and they include all the peas and beans, most of the temperate fruits and nuts, crops of the cabbage, cucumber, and potato families, cotton, tobacco, rubber, tea, coffee, cocoa, cassava, sweet potato, and many vegetables, herbs and spices. Dieback

A plant disease symptom in which stems die backwards from the tip. Diebacks are usually caused either by a pathogen attacking the young tissue of the stem tip, or by a disease in another part of the plant producing toxins that kill the growing point. They can also have a physiological cause, such as a nutrient deficiency.

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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