Rancidity - A chemical change in the fats resulting in unpleasant odours and taste due to formation of peroxide linkage with atmospheric oxygen attacking the double bond, thereby increasing the iodine number inspite of the fact that little glycerol and free fatty acid are released.

Rape - A plant (Brassica napus) related to the turnip and grown for Forage, particularly for sheep, during the autumn and early winter. There are giant and dwarf varieties which produce rapid, succulent, leafy growth, something weeds. It is sometimes included in grass Seeds Mixtures as a Cover Crop and grazed early. It is also often grown as a Catch Crop after Peas or early Potatoes, or in cereal stubble. Rape is very susceptible to Club Root and Mildew. Also called forage rape, cole or coleseed. Certain varieties possess seeds rich in oil.

Ratoon - Emergence of new crop tillers from the root in soil stocks specially in sugarcane and sorghum is known as ratoon and the practice of keeping the same crop for the next season is termed as ratooning.

Ray Fungus - A bacterium (Actinomyces bovis) which forms radiating threads in grasses and cereals and may cause Actinomycosis if eaten by livestock.

Reactor - An animal which is shown to possess a certain disease by a positive response or reaction to a test for the particular disease.

Readily Available Moisture - The volume of water held in the soil between Field Capacity and Permanent Wilting Percentage which is capable of being removed by plants. As a soil dries between these two reference levels the growth rate and yield of a crop are reduced.

Reap - To cut a crop, particularly a cereal, to harvest the grain.

Real Value of Seed - Value of seed sample in comparison to another defined as 'the percentage of pure germinating seeds'. It is calculated by the formula.

Purity % x Germination %
RV =100

Reclaim - To recover land from an undesirable state and put it in a desirable state; to undertake the reclamation of land for example, to drain wet land orirrigate arid land to make it useful for agricultural purposes.

Red Clover - A deep rooting, short lived, species of clover, with an erect hairy stem, untoothed leaflets, short, broad, sharp-pointed stipules, and pale rose flowers.

Red Fescue - A species of grass (Festuea ruhra) normally under-sown in thinly sown spring cereal crops. Best suited to relatively poor upland and marginal soils.

Red Poll - A hornless, dual purpose breed of cattle derived from crosses between the now extinct Suffolk Dun breed and red cattle from Norfolk. The annual average Milk Yield was 3880 kg (3779 litres ; 830 gal.) with an average Butterfat content of 3.80%.

Red Rubies - A popular name for Devon cattle due to their deep cherry red colour.

Reddzlagg - A trade name for heat treated calcined calcium aluminium phosphate one of the main forms of phosphatic fertilizer now in use. It is a finely ground powder containing 32% phosphoric acid (P₂O₅) and a range of minor elements. It can be used on soils at all pH's.

Redmeat - Includes beef, lamb, mutton and venison. By contrast, whitemeat includes veal, poultry meat, rabbit and pigmeat. Pigmeat is an anomaly since it is frequently classed as redmeat by the meat trade. Redwater. A parasitic disease of cattle caused by a microscopic protozoan, Babesia (Piroplasma) bovis, which attacks red blood cells releasing Haemoglobin, and causes listlessness, salivation, fever, diarrhoea, reddish urine, and eventual death if untreated. The disease is transmitted by the common sheep tick,Ixodes ricinus, the intermediate Host.

Reed - 1. A tall grass (Phragmites communis) which grows extensively in thick reed beds in swampy conditions. The dried stems are used in East Anglia for thatching.
2. The uterus of a Ewe.

Reforestation - The planting of trees on land where a forest has previously stood, but has been destroyed, e.g. by a forest fire. (Afforestation).

Registered Seed - Progeny of breeder's or foundation seed handled under procedures acceptable to the certifying agency to maintain satisfactory genetic purity and identity.

Relative Weed - One that may have some use to a fanner in certain circumstances.

Rendzina - A shallow type of soil developed over calcareous rocks, with a brown to black horizon of Mull Humus, often as the only Soil Horizon, over the parent rock. A neutral to alkaline soil with a variable content of free calcium carbonate.

Rennet Curd - Coagulation of milk by the action of the enzyme  rennin. It is also known as sweet curd.

Rennin - An enzyme occurring in the Gastric Juice of young mammals  which causes milk to clot and curdle by converting the soluble protein caseinogen into casein which then forms an insoluble calcium casein compound. This is the principle of cheese making and impure rennin (rennet) is extracted for this purpose from the rennet stomach or abomasum of calves.

Replacement Value (R V) - It indicates extent up to which a given protein could replace some standard protein in terms of nitrogen balance. The formula is :

RV = 100 ­ [Nitrogen balance1 - Nitrogen balance2] x 100
Nitrogen intake1

RV=[Difference in nitrogen balance]  x 100
Nitrogen intake

Replacement values of a particular feed stuff tells us how much quantity of protein part is equivalent to standard protein viz. egg or milk protein By this way we can judge the quality of protein from different sources.

Resazurin Test - A test used to determine the keeping quality of milk.

Re-seed - To re-establish a Ley by sowing seeds of grassland Species, usually in the form of a seed mixture. Reseeding may be carried out after ploughing up a previous ley which has deteriorated, or as part of a rotation

Residual Herbicide - A herbicide which, when applied to the soil,persists for some time, killing weeds on germination.

Residue - That which remains after a part is taken or separated. Agricultural residues refers specifically to the dry portion of agricultural crops as distinct from the fruit, grain or other ingradient for which the crop is grown e.g. stalks, straws, cobs, seed hulls, nutshells, fruit bits. Vegetable wastes, such as green pea vines and bean vines, are sometimes called vegetable residues.

Resting Pasture - One from which grazing animals have been removed to allow it to recover and put on new growth.

Restorative Crops - Crops which are grazed whilst growing so that livestock return organic matter and nutrients to the soil in the form of faeces and urine, e.g., a ley, folder roots, Kale, etc.

Reticulum - The second stomah of a ruminant which receives harder food material passed on from the first stomach or rumen and in which accidentally eaten small stones normally accumulate. Also called the honeycomb stomach after its internal mucous membrane lining which has a honeycomb like structure.

Retting - The exposure of harvested flax to moisture so that it partially rots and the pectin, which binds the fibre bundles to the woody stem, is weakened, allowing the fibres to be more easily separated from the rest of the stem.

Reversible Plough - A popular type of plaugh having two sets of bodies, used for one way ploughing. One set of bodies, turning furrows to the right, are used for ploughing in one direction the other left handed set for ploughing in the other direction. Automatic, hydraulic or mechanical mechanisms are used for turning over the sets of bodies. The reversible plough has the advantage that headland use is much reduced; no ridges, depressions or finishes are left in the field and the surface is left level. They are mainly used for deep ploughing before preparing seed beds for root and vegetable crops. Also called one way plough.

Reversion -1. The process by which soluble monocalcium phosphate, a constituent of superphosphate, is rapidly converted in the soil to the less soluble di-calcium salt, producing a finely divided precipitate which is easily available to plants.
2. A viral disease affecting blackcurrants causing the development of narrower and darker leaves than normal and reducing the amount of fruit produced.

Rex Rabbits - Varieties of fur breeds of rabbit with very fine, densely
textured coats. They can be bred in any colour.

Rhine - A large, broad ditch or open water course in flat marshy areas.

Rhizome - A horizontal creeping underground stem growing just
below the soil surface, from which axillary buds produce new stems and roots giving rise to new separate plants, acting as a foodstore and means of vegetative reproduction, e.g. Couch Grass, raspberry.

Rhode Island Red - A hardy, medium sized, laying breed of Fowl, rich reddish brown in colour with black or greenish blak tail feathers, yellow legs and a single comb. Hens lay large brown eggs.

Rice - 1. Small branches or twigs. Also pea straw.
2. A cereal (Oryza sativa) grown in the tropics mainly for human consumption, poor in fat, protein and minerals. Sometimes fed to poultry.

Richmond's Formula - Based on fat content by Gerber method and specific gravity at 60°F as determined by a lactometer made for this purpose.

TS = 0.25G + 1.2F + 0.14.

Where T S is total solids per cent, F is fat and G lactometer degrees i.e., 1000 (SG-1) at 60°F. (Lactometer readings taken at temperatures other than 60 are corrected to by adding or sub­tracting 0.1 lactometer degree for each degree F above or below(60).

Rick - A stack.

Rickets - A disease of young animals due to a deficiency of either vitamin D or Phosphorus. Bones are unable to absorb Calcium from food and fail to harden or ossify properly. The long limbs tend to bend and develop swellings on the ends at the joints.

Riddle- A large coarse sieve. Also called screen. Riddles of specified mesh size are used to sort Ware Potatoes from a potato crop.