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"Imperial Porphyry" from the Red Sea Mountains of Egypt A waterworn cobble of porphyry Rhyolite porphyry from Colorado; scale bar in lower left is 1 cm (0.39 in). Porphyry (/ ˈ p ɔːr f ə r i / POR-fə-ree) is any of various granites or igneous rocks with coarse-grained crystals such as feldspar or quartz dispersed in a fine-grained silicate-rich, generally aphanitic matrix or groundmass.
Horticulture emerged as a distinct field from agriculture when humans sought to cultivate plants for pleasure on a smaller scale rather than exclusively for sustenance. Emerging technologies are moving the industry forward, especially in the alteration of plants to be more resistant to parasites, disease and drought.
A plant which completes its life cycle (i.e. germinates, reproduces, and dies) within two years or growing seasons. Biennial plants usually form a basal rosette of leaves in the first year and then flower and fruit in the second year. bifid Forked; cut in two for about half its length. Compare trifid. bifoliate
Porphyry (geology), an igneous rock with large crystals in a fine-grained matrix, often purple, and prestigious Roman sculpture material; Shoksha porphyry, quartzite of purple color resembling true porphyry mined near the village of Shoksha, Karelia, Russia; Porphyritic, the general igneous texture of a rock with two distinct crystal ...
A key event in the conservation of plant genetic resources was the establishment of the International Board for Plant Genetic Resources (IBPGR) (now Bioversity International) in 1974, whose mandate was to promote and assist in the worldwide effort to collect and conserve the plant germplasm needed for future research and production. IBPGR ...
Male-fertile non-GM plants must then be grown with the GM crop to ensure pollination. In some cases, a xenia effect due to the genetic difference between the two strains has been observed that increases grain yield, and could make it financially viable to grow the male-sterile plants in such a mixture.
In a general context, both can refer to agriculture. Within agriculture, both can refer to any kind of soil agitation. Additionally, "cultivation" or "cultivating" may refer to an even narrower sense of shallow, selective secondary tillage of row crop fields that kills weeds while sparing the crop plants.
Polyculture is the growing of multiple crops together in the same place at the same time. It has traditionally been the most prevalent form of agriculture. [1] Regions where polycultures form a substantial part of agriculture include the Himalayas, Eastern Asia, South America, and Africa. [2]