Diaphragm valve

diaphragm valve A valve commonly used in irrigation systems that opens and closes as pressure changes on a diaphragm. It can pass mud and small stones.

dias A raised area for seating people such as speakers, leaders, or dignitaries.

dibber See dibble.

dibble or dibber A handheld pointed tool to make holes in the soil for planting seeds, cuttings, bulbs, and seedlings.

dibble hole A depression (hole or cavity) formed in a container or in a planting bed generally the size and shape of the liner, pot, or tube containing a plant's root ball to be placed in it.

dicalcium phosphate A chemical fertilizer with approximately 40% available phosphoric acid.

dichlamydeous Having two kinds of perianth members such as sepals and petals.

dichotomous In botanical terms, forked or divided in two.

dichotomous vein In a leaf blade, veins that fork and fork again, but never cross.

dicotyledon An angiosperm plant (a division of flowering or seed plants) that grows from a seed producing two cotyledons to begin growth. In a scientific name, this is a class of plants that is one of two categories in the angiosperm division. See also plant classification, taxon, and monocotyledon.

didymous A botanical term that means developing in pairs.

didynamous A botanical term, four stamens in two unequal pairs, as with most lamiaceae.

die A tool used for making threads on pipe, etc.

dieback A condition in woody plants in which twigs or shoots begin to die from the tips, often continuing down the plant structure in progressive deterioration. This can be caused by insect infestation, fungus, inadequate water, inability to withstand climatic conditions, extreme weather, early or late frost, nutrient deficiency, etc.

dielectric fitting A special type of adapter used to connect a copper or brass pipe with an iron or steel pipe that prevents galvanic action that otherwise would allow corrosion.

dielectric union A pipe union having an insulator between the two sides of the union to reduce corrosion caused by galvanic action.

differential assessment A property tax relief program for agricultural properties allowing eligible farmland to be assessed at its value for agricultural use rather than its fair market value, or highest and best use.

diffuse In botanical terms, spreading widely and irregularly.

diffuse radiation Diffused or scattered solar radiation. As it passes through atmospheric molecules, water vapor, dust, and other particles, it appears to come from the entire sky. There is no defined shadow as on a hazy or overcast day.

diffusion The transfer of a gas or liquid from an area of high concentration to an area of lower concentration.

digital controller or digital sprinkler controller An electrically operated sprinkler controller with a small (usually) computer capable of being programmed to automatically turn sprinkler valves on and off and keep track of time. It has a screen (various sizes) for reading programmed information regarding the operation of

0 0

Post a comment