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Glossary: F

See: forma specialis
F1, F2, etc.
The letter ‘F’ stands for ‘filial’ and refers to the generation. Thus F1 is the first generation (sons), F2 is the second generation (grandsons), and so on, following the cross of two parents, that are labelled P.
This nomenclature is used mainly with autogamous crops and refers to the self-pollinating generations that follow cross pollination.
Facultative parasite
A parasite that is able to extract nutrients from both a living plant host, and from dead plant material. See also: Obligate parasite.
Fagopyrum spp.
Buckwheat. This one of the pseudo-cereals.
Three species are cultivated. Fagopyrum esculentum is the common buckwheat, F. cymosum is the perennial buckwheat, and F. tataricum is the Tartary buckwheat.
The buckwheats are a very ancient crop originating in China. They are not very important commercially but they have persisted agriculturally for many millennia.
They are open-pollinated and amenable to general improvement by amateur breeders using recurrent mass selection. There is room for improvement in horizontal resistance to both pests and disease.
Fagus sylvatica
The beech. A hardwood tree used in plantation forests. Not recommended for amateur breeders.
A taxonomic group of closely related genera.
Family selection
When working with pure line crops, the technique of family selection, or ‘head to row’ selection, can lead to a more rapid genetic advance.
Family selection means that all the seeds derived from one ‘head’ or ‘ear’, or from one plant, constitute a ‘family’. All the members of one family are planted together, in one row, or in one small plot.
The selection is in two stages. The first stage selects the best families. The second stage selects the best individual plants within those best families. Only the best individuals, from the best families, are kept.
Note: This term has nothing to do with the taxonomic group called a family.
See: Food & Agriculture Organisation of the United Nations.
Farm animal breeding
The breeding of farm animals deserves a mention in a guide to plant breeding for one simple reason. There are no single-gene characteristics of any economic significance in farm animals.
The domination by Mendelian breeders that occurred in professional plant breeding, has been avoided in animal breeding. The improvement of farm animals has involved population breeding, often conducted by individual farmers.
However, a feature common to both kinds of breeding is that heterosis has been exploited in poultry breeding. More recently, artificial insemination has caused a considerable loss of genetic diversity in some species.
Farmer participation schemes
The process of ‘farmer participation’ in plant breeding is to allow farmers some influence in the production of new cultivars.
The participation can vary from the one extreme of a farmer-survey to determine farmer preferences, to the other extreme of the farmers doing the actual breeding -- which we welcome you to do in association with OPBF -- and possibly under the guidance of a professional breeder.
Farmer selection
This is an aspect of some plant breeding programs, including ours, in which the farmers make the final selection of cultivar. It is also known as participatory plant breeding.
Each farmer is given a different group of new clones or pure lines of a crop, emerging from a breeding program. They then grow them and choose those they like best. Their favourites become their own property, with the sole provision that the breeder may have some of them for the purpose of further breeding. The farmers may then grow that material for their own use, and give or sell propagating material to their friends and neighbours.
This farmer selection represents one of the first steps in self-organising crop improvement.
Farmer’s privilege
This is a clause in the plant breeders’ rights legislation of most countries that permits a farmer to use some of their own crop of a registered cultivar for seed on their own farm only. A farmer may not sell any of that crop for seed unless licensed to do so.
However, some seed companies deny this right, particularly with respect to GMOs, by a special clause in the sale contract.
See also: Breeders’ rights.
Farmyard manure (FYM)
The composted excrement of farm animals, mostly cattle, pigs, and horses, but also poultry, and usually mixed with straw, used as a fertiliser for crops. Organic farmers use only natural (i.e., non-synthetic) fertilisers and FYM is one of the most important of these.
Feed grains
Grains, mostly cereals, used for feeding farm animals. Maize is the most important of the feed grains.
The modification or control of a process or system by its own results.
Feedback can be either positive or negative. Positive feedback leads to increase and is destabilising. For example, population growth depends on the number of reproducing individuals. As the population increases, the rate of growth also increases, and there can be a population explosion.
Negative feedback leads to stability. For example, an excess of individuals limits the available food, and leads to a loss of breeding individuals. The population size is then stable.
See also: Homeostasis.
Female sterility
Some crops (e.g., banana) do not produce true seed because of a female sterility. However, male sterility is much more common, and is more useful in plant breeding as a technique for achieving cross-pollination.
Fermentation is the alteration of biological substances by either microbiological or chemical means.
Microbiological fermentation may be constructive (e.g., the production of penicillin) or destructive (e.g., the breakdown of sugars into carbon dioxide and alcohol, in beer, wine, and bread).
Chemical fermentation occurs without the participation of micro-organisms and it occurs, for example, in the fermentation of green tea into black tea, and in the production of silage.
Fertile Crescent
An archaeological term used to describe the fertile area of ancient agriculture that extends from modern Israel in a wide arc to the valley of the Tigris and Euphrates rivers.
This term, which is derived from ‘fertile’, has two meanings in crop science. It can refer to the feeding of crops with compost, farmyard manure or artificial fertilisers; and it can also refer to the sexual fertilisation of a female ovule by a male pollen cell.
Festuca arundinacea
Fescue is a grass used widely for sown pastures. There are technical problems in its breeding.
See: Sorghum bicolor.
Plant fibres give strength to stems.
Some of them can be retted to provide bast fibres for the manufacture of coarse materials such as sacking, sails, and tarpaulins. The most important of these are flax (Linum usitatissimum), hemp (Cannabis sativa), Manila hemp, or abaca (Musa textilis), Sunn hemp (Crotalaria juncea), jute (Corchorus spp.), and sisal (Agave sisalana).
With the development of plastic fibres, the demand for natural bast fibres has decreased dramatically. These crops are now relatively unimportant. Flax, hemp, and sunn hemp are easy to breed, but Manila hemp and sisal are not recommended for amateur breeders.
Note that cotton is a plant fibre, but it is not a bast fibre and it remains a very important crop. There is also some development in the use of hemp and bamboo fibres in fabrics and clothing.
Ficus carica
The edible fig. This is a vegetatively propagated crop of very ancient domestication, which originated in southern Arabia. It has been cultivated in the Mediterranean basin since antiquity and, more recently, it has been taken to all suitable areas of the world.
Several Mediterranean countries produce large amounts of dried figs, and fig paste, for export. The so-called fruit is a complex organ containing numerous minute flowers on its inner surface, and these are pollinated by the fig wasp (Blastofaga psenes), which enters through a very small pore at the distal end.
About 600 distinct clones have been recognised. Dottato is an ancient Roman cultivar of fig that was mentioned by Pliny the Elder (23-79 AD) and which is still being cultivated in Italy. These figs are of interest because of their ancient clones, which demonstrate both the utility and the durability of horizontal resistance.
Fig breeding is technically complicated, and is not recommended for amateur breeders.
Field resistance
Resistance that is apparent in the field but not in the laboratory. This vague term has been widely misused and is best avoided. It is sometimes used, incorrectly, as a synonym for horizontal resistance. See also: Tolerance.
Field screening
A screening operation that is conducted in the field, as opposed to the greenhouse, or the laboratory. Because of the necessity for on-site selection, amateur breeders working with horizontal resistance should always employ field screening, except for a final laboratory screening for certain aspects of quality, which cannot be determined in the field.
Field trials
Typically, these are statistical trials carried out under field conditions. The statistics involved used to be the bane of agricultural students’ lives but these days they are handled entirely by computer.
Note that statistical trials are very valuable when comparing cultivars, spacing, or fertiliser use for variables such as yield and crop quality. But they can be very misleading when comparing treatments for the control of crop pests and diseases, because of parasite interference.
Note also that statistical trials measure the probability of small differences being real differences. Big increases in yield or horizontal resistance do not need statistical trials and, for this reason, they are not usually necessary for amateur breeders.
See: Ficus carica.
See: Corylus avellana.
Finger millet
See: Eleusine coracana.
Fir, Douglas
See: Pseudostuga menziesii.
A disease of trees in the Rosaceae family (e.g., apple, pear, hawthorn) caused by a bacterium called Erwinia amylovora. Diseased trees appear to have been scorched by fire.
Most grain legumes cause flatulence because they contain proteins that are indigestible, and which ferment in the lower bowel to produce carbon dioxide and other gasses. Some reduction of the flatulence factors is possible by breeding, and this could be a breeding objective of amateur breeders.
See: Linum usitatissimum.
Flecks, hypersensitive
See: Hypersensitive.
See: Genetic flexibility.
Flocking of birds
The phenomenon in which birds in flight behave as a single entity. This behaviour is thought to provide protection against predators. It is an excellent example of an emergent property that is observable only at the systems level of the population.
A scientist studying a single bird (e.g., a pigeon) in an aviary could not observe or analyse the flocking habit. This failure to work at the higher systems levels constitutes suboptimisation. See also: Schooling, n/2 model.
A single flower in an inflorescence that is made up of many flowers grouped together.
The reproductive structure of seed-bearing plants, containing either specialized male or female organs (dioecious, monoecious), or both male and female organs (hermaphrodite), such as stamens and a pistil, enclosed in an outer envelope of petals and sepals.
Fodder beet
See: Beta vulgaris.
Fodder crop
Any crop that is grown for feeding farm animals, such as hay, turnips, mangolds, fodder beet, fodder legumes, and fodder grasses.
Fodder grasses
Members of the botanical family Gramineae cultivated for feeding farm animals, as hay, silage, or pasture. See also: Tropical grasses, Pasture grasses.
Fodder legumes
Members of the botanical family Leguminoseae cultivated for feeding farm animals. This tem includes alfalfa, clovers, and vetches, but the pulses are not generally used as fodder.
See: Leaf.
Fomes spp.
Basidiomycete bracket fungi that attack various species of forest trees, including rubber in the Amazon Valley. The brackets grow out of the base of the tree and have spore-bearing tissues in the form of pores (as opposed to gills) on the lower surface.
Food & Agriculture Organisation of the United Nations (FAO)
FAO has its headquarters in Rome, Italy, and was one of the first agricultural institutions to promote the use of horizontal resistance in its International Program for Horizontal Resistance (FAO/IPHR).
Food chain
The food chain is an ecological concept, and it is a form of eating hierarchy, with the smallest and most numerous animals at the bottom of the hierarchy. These animals may eat plants or each other. With increasing rank, the numbers get smaller, and the animals get larger.
As a general rule, the animals of one rank eat animals in a lower rank (except for parasite which may inhabit animals much larger than themselves). Each rank may be thought of as a link in a chain that stretches from the lowest to the highest level. Animals in any rank may also eat plants.
A low concentration of toxins, particularly fat-soluble and water-insoluble toxins such as DDT, in the environment tends to increase as it travels up the ranks of the food chain (see biomagnification), and it may reach dangerous levels at the top of the chain, in birds of prey, and large mammals, including people.
Foreign parasites
Species of plant parasites that are absent from an area, but which could become serious if accidentally introduced. Foreign parasites are the main cause of crop vulnerability.
The cultivation of trees for timber. This term also includes the exploitation of natural forests for timber. Many forest tree species offer scope for amateur breeders, mainly by selection within existing populations. However, because most forest species are open-pollinated, a good parent tree will be only a half-sib.
forma specialis
Usually abbreviated to ‘f.sp.’ (singular) and ‘f.spp.’ (= formae speciales, plural) this taxonomic term means ‘special form’ and is a subdivision of a species of a parasitic fungus that is defined by its host.
Thus Fusarium oxysporum has various formae speciales defined by hosts as widely different as banana, flax, tomato, and date palm. A forma specialis can parasitise only its own host genus, and there are usually wide differences in the levels of horizontal resistance within that genus.
Foundation stock
The original source of seed from which all other grades of seed are produced.
Four-angled bean
See: Psophocarpus tetragonobolus
Foxtail millet
See: Setaria italica.
Fragaria ananassa
The cultivated strawberry, which is one of the most popular and widely cultivated of the soft fruits.
It is an open-pollinated, dioecious, octoploid (2n = 8x = 56) and is a member of the botanical family Rosaceae. Each cultivar is a clone that is propagated vegetatively by runners.
The species exhibits very wide variation and there is scope for amateur breeders. The main breeding objectives, other than yield and fruit quality, are horizontal resistance to various pests and diseases. Suitability for mechanical harvesting also has a high priority, and amateur breeders should know something of the machines available.
Known as olibanum in its centre of production in eastern Africa, frankincense (Old French franc encens = pure incense) is an aromatic gum obtained from trees of the genus Bowellia and, when thrown on to glowing charcoal, it produces an aromatic smoke. Little scope for amateur breeders.
Free enterprise in plant breeding
For most of the twentieth century, plant breeding was considered an esoteric subject that could be handled only by highly trained geneticists. This was largely because of the many difficulties encountered by pedigree breeding for single-gene, vertical resistance.
With the very different approach to breeding for horizontal resistance, using population breeding and recurrent mass selection, plant breeding is so easy that it can be undertaken by amateurs, particularly with the assistance of OPBF or another plant breeders association. When there are many such breeders in the world, there will be widespread free enterprise in plant breeding.
Free trade
Free trade was the key to Adam Smith’s (1723-90) economic theories, which he published in The Wealth of Nations in 1776. His ideas were closely similar to those of modern complexity theory, which recognises the importance of self-organisation in a non-linear system.
Frequency of parasitism
The frequency of parasitism is the proportion of host individuals that are parasitised. The injury from parasitism is the actual amount of damage done to an individual host, or the average amount done to a host population, by the parasite.
In a wild plant pathosystem, the injury from parasitism is inversely proportional to the frequency of parasitism. That is, the higher the frequency, the lower the injury, and, conversely, the higher the injury, the lower the frequency. In this way, the total damage from parasitism never exceeds a tolerable level that does not impair the host's ability to compete ecologically and evolutionarily.
Vertical resistance, with its system of locking, reduces the frequency of parasitism. Horizontal resistance, as a second line of defence, reduces the injury from parasitism. Continuous plant pathosystems, that have horizontal resistance only, usually have a high frequency of parasitism, and a low injury from parasitism.
Frost damage to frost-sensitive plants can easily be mistaken for an infectious disease. See: Physiologic disorder.
In its wide botanical sense, a fruit is any ripened ovary, or group of ovaries, and the associated tissues. More generally, the term is restricted to those fruits, which offer a reward, in the form of sweetness and food, to animals that eat the fruit and unconsciously spread the seed, often in feces, which are deposited far from the parent plant.
The production of true seed in fruit, often as a result of cross-pollination, is an essential aspect of plant breeding. In a culinary context, savoury fruits (e.g., tomato, cucumber, peppers, egg plant) are called vegetables, and sweet vegetables (e.g. rhubarb) are called fruits.
A traditional West African dish originally made from yams (Dioscorea) but more recently from Xanthosoma sagittifoilium.
Fuggle hops
See: Humulus lupulus.
Fumigation is aimed at killing pests with a gas or smoke. The most frequent use is in greenhouses and warehouses. A specialised use is in the treatment of imported produce to keep out foreign pests.
One of the most effective fumigants was methyl chloride, but this substance is now banned because of the damage it does to the ozone layer.
Originally classified as non-flowering plants that lacked chlorophyll, fungi are now put in a separate kingdom.
Most fungi are microscopic and haploid, producing a shortlived diploid form only as a result of sexual fusion.
The fungi are divided into the Ascomycetes (having ascospores), the Basidiomycetes (having basidiospores), the Phycomycetes (having sexual reproduction that does not involve either ascospores or basidiospores), and the imperfect fungi, that have no known sexual reproduction.
Many of the fruiting bodies are macroscopic, and are known as mushrooms, toadstools, puff balls, etc. Most fungi are very valuable reducers, but a few are parasitic on plants and the cause of plant diseases.
A pesticide that kills a fungus. Most fungicides are synthetic and are proprietary compounds that are used to control plant diseases, but a few have medicinal, veterinary, and domestic uses.
The most famous, and spectacularly successful fungicide was Bordeaux mixture, discovered by Millardet in France in 1882.
A protective fungicide is one that is entirely external and which prevents infection. It thus protects the host plant from disease. A systemic fungicide is one that is absorbed by the plant and can kill an internal fungus. It thus cures a disease.
Fusarium oxysporum
This fungus causes wilt diseases in many different hosts. The pathologically induced wilt is usually caused by a combination of xylem vessels that are blocked by the presence of the fungus, and by toxins produced by the fungus.
This fungus has a very wide host range and its various formae speciales are usually named after their hosts, or the area of their first discovery.
Thus f.sp. cubense causes Panama disease of banana, f.sp. albedinis causes Bayoud disease of date palms, f.sp. lycopersici causes tomato wilt, f.sp. apii causes celery wilt, f.sp. conglutinans causes cabbage yellows, f.sp. dianthi causes carnation wilt, f.sp.lini cause flax wilt, f.sp. pisi cause pea wilt, f.sp. vasinfectum causes cotton wilt, and so on.
Amateur breeders can accumulate horizontal resistance in the annual hosts but crops such as banana and date palm are definitely not recommended for them.
Note that the various f.spp., of this fungus exhibit a differential interaction with their host species, but that this differential interaction is not due to vertical resistance. See also: Verticillium.
See: Farmyard manure.