Seeds production

Target plants per x 1000 seed weight in grams Predicted percentage establishment 

Breeders seed, Pre-Basic, Basic, Cl and C2 generations are produced for wheat, barley and oats. There is no C2 generation for rye or triticale. Basic, Cl and C2 seed can at present be certified at two levels, EU minimum standard and HVS 

The minimum requirements for previous cropping are outlined in Table 12.1. Certain cultural practices, such as early auturun drilling and minimal cultivation, create greater risks of volunteers being carried over to a seed crop and in such circumstances a longer break will be advisable. 

Important weeds are wild oats, cleavers, bromes and black-grass. Seed crops should not be grown in fields where these are likely to be a major problem. Light populations of wild oats and other cereal species (e.g. barley in wheat) may be rogued out of a seed crop and should then (in the case of wild oats) be removed from the field in a plastic bag and burned. 

Crop Grade of seed Previous cropping requirement  

The first question is largely answered in the former paragraph, the second one will be addressed by discussing diversity, technical aspects and seed quality standards. 

There are roughly two groups of farmers involved in this difficult area. The first is those small-scale farmers who focus on the local market with the use of local and old varieties, the 

The main problems in organic seed production are nutrient management, disease and pest management, and weed control. Among the seedborne diseases in particular require special attention. To reduce the risk of disease infestation, optimal climatic conditions and thus the location for seed production can be important (Dornbusch et al. 1992 Velema 2004). In some cases seed production should be located in warmer and drier climates, away from the areas of origin and destination. 

For some crops there is no problem in meeting the quality standards as required for conventional seeds, but in some cases the thresholds for seedborne diseases are adjusted (Nielsen 2003 Lammerts van Bueren et al. 2003a Girsch and Weinhappel 2004). In some countries the recommended tolerances or thresholds for some diseases are lowered. In Austria, for instance, the threshold for Fusarium nivale has been adjusted from 20% in conventional agriculture to 10% for the organic sector. In the Netherlands, the level of permitted contamination in organic seed potato has been lowered from 25% (conventional) to 10%. A lower threshold is also set in other diseases, for example, in Austria, 10% is permitted for Septoria nodorum in cereals, compared with 20% previously. 

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Tamarind Gum. Tamarind gum [39386-78-9] is another seed gum with potential industrial appHcation. It is obtained from the seed kernels of the tamarind tree, Tamarindus indica which is cultivated in India and Bangladesh. The seeds are a by-product from the production of tamarind pulp which is used as a food flavor. Seed production is 150,000 t/yr. 

Yan J. Wang J. Tissue D. Holaday A. S. Allen R. Zhang H. (2003) Protection of photosynthesis and seed production under water-deficit conditions in transgenic tobacco plants that over-express Arabidopsis ascorbate peroxidase // Grop Sci. V. 43. P. 1477-483. 

Several alkenes occur naturally in living organisms. Some of these alkenes act as hormones and control biological functions. Plants produce ethene as a hormone to stimulate flower and seed production and to ripen fruits. Ethene stimulates enzymes in the plants to convert starch and acids of unripe fruit into sugars. The enzymes also soften fruit by breaking down pectin in cell walls. 

Ecological succession is the orderly process of community change and is the sequence of communities which replace one another in a given area (3). Generally, the driving force behind succession has been attributed to changes of physical factors in the habitat, availability of essential minerals, differences in seed production and dispersal, competition, or a combination of these. In addition, Rice and co-workers (as cited in 1 ) have indicated that... 

Tea flowers are globular, about 3 to 5 cm in diameter, white, and delicately fragrant. They are borne in the axils of scale leaves (small leaves that do not develop further) and may occur singly or in small clusters. There are five to seven petals and an equal number of sepals. The flowers are mostly self-sterile and are produced in cycles corresponding to leaf growth, and require 9 to 12 months to form mature, round seed pods 1 to 1.5 cm in diameter. The tea plant is not generally allowed to flower during production cycles, with only a small number of the plants allowed to go to seed production to maintain seed stock. 

Seed quality depends heavily on the climatic characteristics of site locations. Thus, in order to limit seedbome disease inocula, seed production should be in areas characterized by low rainfall during flowering and ripening stages and by soils with low soil-nitrogen levels. 

Copper is an essential micronutrient required in the growth of both plants and animals. In humans, it helps in the production of blood haemoglobin. In plants, copper is an important component of proteins found in the enzymes that regulate the rate of many biochemical reactions in plants. Plants would not grow without the presence of these specific enzymes. Research projects show that copper promotes seed production and formation, plays an essential role in chlorophyll formation and is essential for proper enzyme activity, disease resistance and regulation of water in plants (Rehm and Schmitt, 2002). 

Downey, R.K., and Beckie, H.J. (2002). Isolation Effectiveness in Canola Pedigreed Seed Production. Internal Research Report, Agriculture and Agri-Food Canada, Saskatoon Research Centre, Saskatoon, SK, S7N 0X2, Canada. 

Efficient seed production and high yields Oilseed plants are efficient seed producers. 

Bryant LA, Montecalvo J Jr, Moren KS, Loy, B. Processing, functional, and nutritional properties of okra seed product. JFood Sci OffPubl Inst Food Technol 1988 53 810-816. 

Mayer DJ, Price DD. (1976). Central nervous system mechanisms of analgesia. Pain. 2(4) 379-404. Meadway C, George S, Braithwaite R. (1998). Opiate concentrations following the ingestion of poppy seed products—evidence for "the poppy seed defence". Forensic Sci Int. 96(1) 29-38. 

The majority of leafy herbs reach maximum flavor just before the flowers open. After that point, the texture and flavor of leaves change as the plants put energy into flower and seed production. Remove all flowers to extend the production offender leaves, unless you are growing the herbs for flowers or seed. 

The effect of ozone injury on herbaceous plant reproduction has been mentioned earlier in this chapter and in Chapter 11. Seed production by annuals is influenced mainly by the envirorunental conditions of the current year, but perennial woody plants—particularly conifers—are erratic seed-producers. Intrinsic factors affecting cone production include age and vigor seasonal temperature and soil moisture are important environmental factors. ... 

The effects of sulfur dioxide on cone production have been described by Scheffer and Hedgcock and Pelz. Generally, the decrease in tree vigor caused by the pollutant may eliminate or lower the frequency of cone production and diminish the size, weight, and germination of seed. The effects of chronic ozone injury on conifer seed production may be similar, in that tree vigor is drastically reduced. The effects of chronic ozone injury on ponderosa and Jeffrey pine seed production are under investigation by Luck (in Kickert et al,... 

Insect disinfestation of seed products, flours, fresh and dried fruits, etc. 0.2-0.8... 

Kaempferol can increase seed production in Petunia, whether produced as a result of pollination or by wounding. It has been suggested that the reproductive function of flavonols may have evolved from a defensive role. Allelopathic flavonoids in the stigma may prevent introduction of pathogens into the pistil. 

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