Paraquat for maize

MaizeMaize, often called corn, along with wheat and rice is one of the world’s top crops. Maize provides basic staple foods for much of the world’s population. All around the world maize grain is a basic livestock feed, and the crop can be cut while still green to make silage as a winter feed. Also, increasing amounts of maize in the US are being used to make bioethanol

Description

Bioethanol is ethanol of biological origin. Crops containing sugar or starch grown for energy use include sugar beet, sugar cane, maize and wheat. "2nd generation" bioethanol will be made from cellulose from, e.g. waste straw and stover, willow and popular trees, sawdust, reed canary grass, switchgrass, Miscanthus.

Authoritative On-line References and Resources

http://www.eere.energy.gov/afdc/fuels/ethanol.html The US Department of Energy's Office of Energy Efficiency and Renewable Energy has am Alternative Fuels and Advanced Vehicles Data Center containing key information on all biofuels.
fuel.
Maize, perhaps more than any other crop, reaches both high and low extremes of sophistication, mechanisation and technology in crop production. But, all farmers need to maximise the yield and quality of their produce, while saving the costs, time and labor needed to grow it. Broad-spectrum herbicides, led by the introduction of paraquat in the 1960’s, have allowed the adoption and growth of soil cultivation systems which do not rely on controlling weeds by burial from ploughing. In the US Corn Belt, although some of the most highly erodable land has been taken out of production, and erosion has decreased since the ‘dust bowl’ days of the 1930s, the average annual loss of soil by erosion has been estimated to be 14 tonnes/hectare, a rate way above what can be replaced by natural processes of soil formation.

Maize fact file

  • 185 million ha grown worldwide in 2013
  • 44% increase in yield since 1995
  • 38% of the US crop will make bioethanol in 2013
  • 5 times higher yields in most productive countries than in least
  • 2nd most widely grown GM crop
  • 0: no-till

    Description

    Also known as conservation tillage or zero tillage is a way of growing crops from year to year without disturbing the soil through tillage ie cultivating the soil usually with tractor-drawn implements.

    Authoritative On-line References and Resources

    No-till.com:  A portal for on-line information about no-till farming.
    cultivated on 25 million ha in USA
Abandoning the mouldboard plow in conservation tillage

Description

Any tillage and planting system that covers 30 percent or more of the soil surface with crop residue after planting to reduce soil erosion by water.

Authoritative On-line References and Resources

Purdue University-based Conservation Technology Information Centre.
systems saves cash, time and fuel, improves soil structure, reduces erosion and provides havens for wildlife. In spring, weeds or a cover crop

Description

Cover crops are primarily planted not to be harvested for food but to reduce soil erosion, control weeds and improve soil quality. They are usually plowed or tilled under before the next food crop is planted, in which cases the "cover crop" is used as a soil amendment and is synonymous with "green manure crop."

Authoritative On-line References and Resources

http://attra.ncat.org/attra-pub/covercrop.html ATTRA is the US National Centre for Appropriate Technology's Sustainable Agriculture Information Centre.
such as rye, wheat or oats have to be controlled by a burndown herbicide, typically either paraquat or glyphosate.
Paraquat-based burndown sprays are more reliable than glyphosate when the weather is cold and rain falls soon after application. Particularly under such challenging weather conditions, paraquat will control weeds in a few days compared to glyphosate’s 2-3 weeks. Glyphosate is a systemic herbicide and gives a thorough kill of many perennials

Description

Weeds that return year after year. Some die back in the winter but their roots remain alive and shoots reappear in spring; some don't die back and grow in size and stature the next season.

Authoritative On-line References and Resources

The International Weed Science Society represents individual associations around the world.
. However, intensive use of glyphosate has resulted in changes in the spectrum of weeds towards species which are harder to control and the evolution of resistant biotypes in some species which are no longer controlled by glyphosate. This has led to the development of integrated weed management

Description

A decision support system for crop protection which focuses on long-term prevention or suppression of pest problems with minimum impact on human health, the environment, and non-target organisms. IPM takes into consideration all available pest control techniques and tactics (cultural, mechanical, biological, chemical). IPM emphasizes the growth of healthy crops for better productivity with the least possible disruption to agroecosystems.

Authoritative On-line References and Resources

http://www.ipmcenters.org "The USDA's National Site for the Regional IPM Centers' Information System provides information about US commodities, pests and pest management practices, people and issues."
systems. 
In the US, it is becoming accepted that over-reliance on glyphosate and the concurrent reduction in diversity, will exacerbate weed resistance

Description

The inherited ability of a plant/weed to survive a dose of a herbicide normally lethal to that species.

Authoritative On-line References and Resources

http://www.weedscience.org/in.asp The International Survey of Herbicide Resistant Weeds monitors the evolution of resistant species and assesses their impact. All confirmed instances of new cases are listed.
problems. No more than two applications of glyphosate should be applied to any one field over two seasons. Paraquat can provide the alternative means of effective and Maize cobs formingsustainable weed control.
Maize is usually grown in a rotation with other crops, often soybeans which improve the fertility of the soil for the following maize crop, reducing the need to apply nitrogen fertilizer. In warmer climates, it is possible to grow crops of maize and soybeans in the same season. However, a fast-turn around time between crops must be achieved and conserving soil moisture is important. No-till techniques and using fast-acting paraquat for weed control can provide this, often giving as much as a 10 day lead over any glyphosate program. In less developed farming systems, paraquat is widely used to control weeds growing between rows of the standing crop. Because it is not systemic like glyphosate, so causes only minor contact damage when sprayed carefully or using shielded sprayers, and has no activity or residual effects via the soil, it provides a fast and effective alternative to the drudgery of manual weeding.