Weed control methods

Gangstad, E. 0. n "Weed Control Methods for Recreational Facilities Management" Gangstad, E. 0., Ed. CRC Press, Boca Raton, FL 1982, pp. 77-94. 

Bell CE, Elmore CL (1983) Soil solarization as a weed control method in fall planted cantaloupes. 

Summarizing the growth of the utilization of petroleum oils in herbicides, an evaluation is made of the present-day chemical weed-control methods in which oils are employed—as toxicants, as solvents, as filming agents, and as carriers. The unique properties of oil in the pest control of the future are also indicated. 

Melander, B. and Heisel, T. 2002. Prospects and limitations for agricultural engineering in the development of sustainable weed control methods - examples from European research. Paper presented at Australian Conference on Agricultural Engineering. Charles Sturt University, Wagga Wagga. 

Lange, A.H. (1970). Weed control methods, losses and costs due to weeds, and benefits of weed control in deciduous fruit and nut crops. 

Role of Triazine Herbicides in Sustainable Agriculture Potential of Nonchemical Weed Control Methods as Substitutes for Herbicides in United States Corn Production... 

USDA-ARS has compiled agronomic, economic, and environmental data from a small Iowa farm that stopped chemical weed control in 1968, as well as from a neighboring conventional farm for comparative study (USDA NSTL, 1993). The information that follows describes the experiences of the small farm using nonchemical weed control methods. 

Triazine herbicides provide cost-effective, broad-spectrum weed control and are key tools in conservation tillage. Although the chemical alternatives to the triazines are more costly and generally less efficacious, they are considerably more reliable as weed control methods and more compatible with current farming operations than available nonchemical weed control methods. Even as more com acreage shifts to herbicide-tolerant com, the need remains for residual herbicides such as the triazines to manage resistant weeds and to avoid the need for multiple tillage passes for weed control. 

Cultivation is unreliable as a weed control method within the rows and when fields are wet. 

Microbes (plant pathogens) and microbial products (phytotoxins) have been shown to have potential as weed control agents. Growth in the interest in these alternative weed control methods has been brought about by a need for less persistent, more selective, and more environmentally safe herbicides. Broad-spectrum and selective activity are concepts important to the development of a weed control agent. 

Herbicide resistance in crops offers flexibility in weed control methods which is very important, especially under conservation tillage and with minor crops. 

The immediate and total removal of weeds is often recommended. However, this recommendation may be based more on when control methods can most easily be appHed, rather than on considerations of the optimal time for effective weed control (454). Controlling plants that are not actually problems or that are present at noncritical times is cosdy and may not truly benefit the producer. However, weeds that are present initially ia very low numbers may require subsequent eradication if iatroduction of a new noxious species is to be prevented. 

Massantini, F., Caporali, F., Zellini, G. Symp. on the Different Methods of Weed Control and Their integration. 1977, 1, 23. 

An annual estimated cost of approximately 938,835,000 is required for labor and equipment to apply 204.5 million kilograms of herbicides to 147.6 million hectares of cropland in the United States (Table IV). Mechanical tillage to control weeds between cropping seasons and interrow tillage of crops has been used for centuries as a very effective method of weed control. Approximately 50% of all tillage between crops is done to control weeds. The number of cultivations required for effective weed control within a row crop varies from two to five during a cropping season. 

Application methods Usually as water spray or in liquid fertilizers applied preemergence, but also may be applied preplant or postemergence. Rates of 2-4 pounds/acre (2.24-4.48 kg/ha) are effective for most situations higher rates are used for nonselective weed control, and on high organic soils... 

Esperancini MST, De Souza NL, Baldini EM (2003) Economic evaluation of solarization method for weed control. Cientifica 31 123-130... 

Sales Beuno SC, De Holanda Maia A, Blat SF, Christoffoleti PJ (2003) Resting time of moist substrate to solarization as method for weed control. Acta Hort (ISHS) 607 221-226... 

Sauerbom J, Linke KH, Saxena MC, Koch W (1989) Solarization a physical control method for weeds and parasitic plants (Orobanche spp.) in Mediterranean agriculture. Weed Res 29 391-397... 

Hence, allelopathy alone can not be a sufficient tool for weed control. Combinations of methods that prevent weed germination and control weeds have to be used (Rasmussen 2004). 

Providing weed suppression through the use of allelopathic cover crops is an important method of weed control in organic farming and it is one of the best possibilities of allelopathy application (Sullivan 2003a). Besides, growing of cover... 

The effect of applied plant residues can be positively influenced by an increase of temperature. Mallek et al. (2007) established that dried and milled crop residues of onion (Allium cepa L.) or garlic (A. sativum L.) were able to reduce seed germination of barnyard grass (E. crus-galli (L.) R Beauv.), common purslane (Portulaca oleracea L.), london rocket (Sisymbrium irio L.) during their decomposition in soil, but only at the elevated (39°C) soil temperature. It can support combination of methods for weed control, in this case allelopathy with soil heating treatments (e.g., solarization). 

Pollen allelopathy can find utilization in field cultivations that could contain pollen of allelopathic crops or weeds. Pollen allelopathy could be an effective method for annual weed control that reproduce, at least in part, via wind pollination and flower concurrently with the allelopathic species. The effects of allelopathy should result in the loss of genetic variation and so in reduction of reproductive ability, but some plants are probably able to detoxify the pollen allelochemicals (Murphy and Aarssen 1995a, b). Murphy and Aarssen (1989) suggested possible delaying of weed flowering at later, less favorable times of the season or diurnal period, so decrease in weed pressure. However, infestation by perennial weeds can worsen due to compensation of pollen allelopathy through increase in the formation of rhizomes. 

Allelopathic compounds act as repellents for herbivorous pests, so the same strategy used in weed control could be effective against pests and pathogens. Only allelopathy is not possible to use the complete control of weeds, pests or diseases it is necessary to combine it with other methods of plant protection. 

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