Weed and Seed

If the process is properly conducted, it is possible to kill all the pathogens, weeds, and seeds during the composting process. To do this, the temperature must be maintained between 333 and. 344 K (140 and 160°F) for 24 h. 

Cavanagh, Suzanne, and David Teasley. Community Anti-Crime Weed and Seed Program Current Developments. Washington, D.C. Congressional Research Service, 1998. Describes the Weed and Seed program, an effort... 

In 1900, over 50% of the medicines in the United States Pharmacopoeia were still botanical products. These weeds and seeds were usually bought in bulk or intermediate form and then compounded to meet the requirements set down in the physician s prescription. In order to be a successful apothecary, one had to know the names, both common and official, of these botanical medicines. 

There are two principal approaches to the biological control of weeds (483—485). The first approach is referred to as classical or inoculative biological weed control. Plants that have been introduced to areas outside of their natural range often encounter fewer growth and seed dissemination... 

Use pattern Terbacil is a substituted uracil herbicide used primarily to control annual and perennial grass and broadleaved weeds in apple orchards, alfalfa, asparagus, mint and sugar cane. Other minor uses include blueberries, strawberries and seed grasses... 

The classic seed burial studies of W. J. Beal and his successors have shown seeds of at least one weed species, Moth Mullein (Verbascum blattaria L.) can remain viable in soil for a peiod of 100 years, whereas three species continued to germinate after 80 years of burial (30). Weed seeds not only resist decay by soil microbes, but they vary in dormancy characteristics. There is considerable evidence that chemical inhibitors are responsible for both phenomena. Unsaturated lactones and phenolic compounds in particular, are potent antimicrobial compounds present in many seeds (4J. Fruits and seeds are also known to contain diverse germination inhibitors including phenolic compounds, flavonoids and/or their glycosides and tannins. Unique methods to destroy inhibitors could provide an excellent weed management strategy. 

Shirtliffe, S.J., Entz, M.H. and Van Acker, R.C. (2000). Avena fatua development and seed shatter as related to thermal time. Weed Sci., 48, 555-560. 

Eleftherohorinos IG, Giannopolitis CN (1999) Alternatives to methyl bromide for the control of weeds in greenhouses and seed beds. In Proceedings of international workshop alternatives to methyl bromide for the Southern European countries , 7-10 December. Heraklion, Crete, Greece, pp 34-36... 

A chemical stimulant, a root exudate, is required to break seed dormancy of a parasitic weed and initiate seed germination. Upon receiving a signal for germination, a radicle emerges from the seed coat. However, an additional chemical signal is needed for the radicle to penetrate host roots and form a haustorium. Therefore several plants can serve as catch crops or trap crops for the reduction of the parasitic weed seed bank in infested soil. 

Liebman M, Sundberg DN (2006) Seed mass affects the susceptibility of weed and crop species to phytotoxins extracted from red clover shoots. Weed Sci 54 340-345 Lin D, Sugitomo Y, Dong Y, Terao H, Matsuo M (2006) Natural herbicidal potential of sauru-raceae (Houttuynia cordata Thunb.) dried powders on paddy weeds in transplanted rice. Crop Prot 25 1126-1129... 

Although chemicals are now used extensively in the control of rice pests, the demand for chemicals in this field is expected to be much greater in the future. Many chemicals now available have not been tested in countries where severe losses occur. In the developmental field, more satisfactory herbicides are needed for the control of broad-leaf weeds and grasses, better fungicides are needed to supplement breeding work for the control of foliar rice diseases more effective seed-treatment chemicals are needed for rice sown in water and satisfactory chemical repellants are needed to prevent losses from bird pests on maturing rice. 

The soil in the chinampa was prepared in the traditional way of peasants at Xochimilco, by making a seed bed with mud from the bottom of the channels that surround the chinampa. When the mud was dry, it was cut in small cubes where the seeds were planted. The seedbed was then covered with soil and twigs. Once the seedlings reached 10-15 cm they were transplanted to a plot previously weeded and plowed. Treatments were placed randomly and covered with mud. These were 1. control (without fertilizer) 2. inorganic fertilizer (10 10 15), 250 g/m ... 

Many seeds become dormant as a means of survival and are able to germinate after many years in the soil. Factors that influence seed germination and seed dormancy include temperature, moisture, oxygen, light, inhibitors (e.g., allelopathic effects), hardness or impermeability of seed coats, mechanically resistant seed coats, immature embryos, and after-ripening requirements (e.g., cool temperatures for several months). Weed seeds may survive and germinate due to several of these characteristics (Pareja et al, 1985). 

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