Tag Archives: Herbicides

Organic Vegetable Crops Require Thousands of Hours of Weeding by Hand

Posted on by
Reply

The biggest constraint to the expansion of organic crop growing is the lack of chemical controls for weeds – herbicides. Hand weeding is often required to remove weeds from organic fields. A very large number of worker hours are required for weeding, as reported in a recent article from Germany…

“In organic crop production, manual control of weeds is still laborious in a number of row crops that have poor competitive ability. It is difficult to control weeds that grow within the crop rows (intra-row weeds) by physical weed control; typical figures for hand-weeding time are in the range of 100-400 hours/hectare in carrot, direct-sown leek and onion, and it has even been reported to exceed 1000 hours/hectare.” 

Authors: J Rasmussen¹, C B Henriksen¹, H W Griepentrog² and J Nielsen¹
Affiliations: ¹University of Copenhagen, Denmark; ²University of Hohenheim, Germany
Title: Punch planting, flame weeding and delayed sowing to reduce intra-row weeds in row crops.
Publication: Weed Research. 2011. 51:489-498.

US Drought Effects Would Be Worse Without Pesticides

Posted on by
Reply

The current drought has received extensive media coverage. There will be no Dust Bowl this year thanks to the use of pesticides. Farmers have been using herbicides instead of tilling the soil for weed control. By not disturbing the soil, they have conserved soil moisture. Corn yields would be worse if it were not for herbicide technology, a point made in an editorial by David Bridges, President of Abraham Baldwin Agricultural College in Tifton, GA.

“The Midwest ‘flash drought’ is withering much of our 2012 corn crop. … Now is the perfect time to consider the benefits to farmers, consumers and the environment of something routinely demonized by activists – pesticides. Pesticides? Yes. Without them, things would be worse, on all ends of our current dilemma.”

“Between 1980 and 2011, corn yields here grew by 64 percent while soil loss dropped 67 percent, energy use dropped 43 percent and carbon emissions fell 36 percent. Of vital importance this year: Irrigation water use for corn dropped 53 percent in the same period.”

“Pesticides and other technologies conserve natural resources while providing a production buffer that limits the effects of natural disasters and the disruptions of unforeseen shortages.”

USA Today echoed these sentiments on August 20.

“The severe drought that has hit the Farm Belt does not immediately threaten to create another Dust Bowl or widespread crop failure, thanks to rapid innovations in the past 20 years in seed quality, planting practices and farming technology, farmers and plant scientists say. … In the past 20 years, farmers have transformed from plowing fields 8 to 11 inches deep to ‘no-till’ or ‘conservation-tillage’ practices designed to minimally disturb the ground. That exposes the soil to less wind erosion, preserves natural nutrients, and captures and retains what moisture does fall.”

Author: David Bridges
Affiliation: Agronomist and President of Abraham Baldwin Agricultural College, Tifton, GA
Headline: Drought Would Be Worse Without Pesticides
Publication: Des Moines Register, Wednesday, July 25, 2012.

Author: Chuck Raasch
Headline: Another Dust Bowl for Farm Belt Unlikely
Publication: USA Today, Monday, August 20, 2012

Italian Farmers Realize Profits from Herbicide Applications

Posted on by
Reply

In Italy, herbicides to kill weeds in crop fields have been routinely used on almost all the acres for the past 30 years. Is the cost of the herbicide application justified considering the levels of weed infestation? Italian researchers examined the record…

“The frequency distribution of yield loss due to weeds in winter wheat, sugar beet, maize and soybean has been studied using the available data of weed control trials undertaken in north-central Italy in the last 30 years. The breakeven yield loss and the probability of obtaining a positive net return from chemical weed control were calculated, considering different treatment options and different weed-free yields.”

“In winter wheat the probability of a positive net return from chemical weed control is high, between 80.5 and 97.3%. … As far as other crops analysed are concerned, the probability of a chemical treatment being profitable is >80% in maize and soybeans and >95% in sugar beets.”

“The profitability of chemical weed control depends on the density, composition and time of emergence of the weed flora, on the competitiveness of the crop and on the chemical used. In most cases, however, it is profitable to spray; in other words in the Po Valley there is a high degree of probability that the weed density is sufficient to bring about a yield loss greater than the treatment cost.”

Authors: G. Zanin¹, A. Berti² and M. Giannini³
Affiliation: ¹ Instituto di Agronomia Generale e Coltivazioni Erbacee, Padova, Italy; ² Centro per lo Studio dei Diserbanti del CNR, Padova, Italy; ³ ESAV, Venice, Italy
Title: Economics of herbicide use on arable crops in north-central Italy.
Publication: Crop Protection. 1992. 11:174-180.

Denmark Leads the World in Spinach Seed Production Thanks to Modern Crop Protection

Posted on by
Reply

Denmark is a world leader in production of vegetable seeds that meet very high quality standards and are exported to growers around the world. In order to grow a high quality seed crop economically, Danish seed growers use herbicides to control weeds and fungicides to control plant diseases. Recently, an assessment was made as to whether Denmark can maintain its position as the leading spinach seed supplier, and the results show…

Can Denmark keep the position as the biggest spinach seed producer in the world?

  • Yes, if Denmark is allowed to use proper herbicides and fungicides
  • Yes, because Denmark has good climatical growing conditions for spinach – good soil, sufficient rain and long days
  • Yes, because Danish farmers are highly skilled and have top mechanization
  • Yes, because Danish seed companies have very good processing facilities
  • Yes, because Denmark has a very good infrastructure
  • and… Yes, because Denmark will fight for it!

Author: Henning van Veldhuizen
Title: Can Denmark keep the position as the biggest spinach seed producer in the world?Presented at: 2011 International Spinach Conference, October 3-4, Amsterdam, The Netherlands.

Guyana’s Economy Boosted by Using Herbicides in Rice Fields

Posted on by
Reply

Guyana stands alone in the world in terms of the proportion of rice that they export – 65%! Rice is the highest agricultural foreign exchange earner for Guyana. In order to maximize rice yields, rice growers in Guyana rely on herbicides to control weeds.

“Guyana’s rice industry for 2008 has exported US$118M, which represents the highest earnings ever for the sector. … Rice continues to make significant strides as a socioeconomic crop in Guyana. From a very small and quite subsistence beginning, it has grown today to one of the pillars of Guyana’s economy.”

“Weed control continued to play a major role in maximizing rice yields during 2008. … Despite the use of preventative measures and cultural practices that normally reduce weed infestation, surviving populations of the major rice weeds were significant enough to warrant the use of chemical control measures in order to maximize grain yield.”

Authors: Jagnanne Singh and Dindyal Permaul
Affiliation: Guyana Rice Development Board
Title: Guyana Rice Development Board Annual Report 2008.
Available at: http://grdb.gy/templates/GRDB/images/GRDB%20Annual%20Report%202008.pdf

30 Years Ago, We Knew Herbicides Increased Canadian Wheat Yields

Posted on by
Reply

Canada ranks sixth in the world in wheat production and is the second largest exporter of wheat with 70% of its production exported annually. Since 1960, wheat yields have doubled in Canada. A group of Canadian researchers set out to identify the key factors accounting for the yield increase…

From abstract: “Therefore, we suggest that chemical weed control was the main contributing factor to the yield increases. This control has resulted not only in reduced competition from weeds, but also in better seedbed moisture because fewer cultivations are needed in the spring. “

“Because of the ability to control weeds with chemicals, it is now also possible to seed shallowly into a moist seedbed immediately after one cultivation since numerous spring cultivations with a resultant loss of valuable soil moisture are no longer necessary to eliminate germinating seeds. Fertilizer application and improved cultivars have also contributed, but to a lesser degree, to the yield increases.”

Authors: S. Freyman et al.
Affiliation: Agriculture Canada, Lethbridge, Alberta, Canada
Title: Yield trends on long-term dryland wheat rotations at Lethbridge.
Publication: Canadian Journal of Plant Science. (1981) 61:609-619.

Sustainable Ag Pioneers Learn Value of Modern Herbicides

Posted on by
Reply

Dick and Sharon Thompson of Boone, Iowa are pioneering giants of the sustainable agriculture research agenda in the U.S. They helped found Practical Farmers of Iowa. Since 1986, the Thompsons have conducted on-farm research trials and have produced an annual report. The Thompson farm is not organic; however, they generally do not use herbicides, preferring to use a rotary hoe to destroy weeds. In most years, the mechanical control works well, but then came the very rainy 2008 growing season…

“2008 was not a good year for soybeans because of weather, rain and more rain. This was the first year that we lost money on a soybean field. We could not rotary hoe. The beans were good size when we cultivated the first time (June 24). The cultivator threw soil in and around the bean plants, looked like an excellent job. It rained 1.25 inches two days later on June 26 starting all the weed seed we pushed into the row. We had grass in the row, which is not the norm, along with broadleaf weeds. … The field was a mess. The rope wicks attached [to] our old hyboy filled with round up [herbicide] went up and back on the same rows to kill the weeds so that our small combine could harvest the field. The rope wick killed the weeds and the combine was able to handle the dead weeds. The yield was 37 bushel per acre, 7 bushel below county average of 44 and we lost $49 per acre. The field was sprayed for aphids adding more expense.”

“We could not manage weeds in the end rows of corn and soybean fields without herbicides.”

Authors: Dick and Sharon Thompson
Publication: Thompson Agriculture Alternatives 2009 Report
Available at: http://www.practicalfarmers.org/resources/alternatives-in-agriculture.html

Herbicides Eliminated Inhumane Drudgery of Weeding Rice

Posted on by
Reply

For centuries, rice fields in Japan were weeded by millions of people who spent their summers in the hot, humid, muddy fields working in a stooped position that could cause permanent back pain and damage. Herbicides freed people from this drudgery…

“For a long time before 1949, all weeding in rice fields had to be done by man-power. It was so severe and cruel labor for farmers. Modernized weeding, that is with the use of herbicides, has saved them from these physical and mental pains.”

“Herbicide has brought a great benefit to rice cultivation… in liberation from the inhumane physical and mental pains of farmers during serious weeding labor in hot, humid and muddy paddy fields. …for the ‘perfect’ hand weeding we need 506 hours/hectare, which can be calculated as the work of 1.89 million people every day for 60 days in summer all over Japan. It is not practical in the present status in this country.”

Author: Shooichi Matsunaka
Affiliation: Former President of the International Weed Science Society
Title: Historical review of rice herbicides in Japan
Publication: Weed Biology and Management. 2001. 1:10-14.

Jimmy Carter Lived the Weed Nightmare

Posted on by
Reply

Our 39th President, Jimmy Carter, grew up on a peanut and cotton farm long before herbicides were available to manage weeds. In his autobiography, President Carter recounts the nightmare of trying to control weeds with tractors and hand labor.

“Our part of Georgia receives about fifty inches of rain during an average year, mostly during the spring and early summer… However, depending entirely on draft animals and hand labor, small variations in the rain pattern could be devastating. … The dry ground permitted the mule-drawn cultivating plows and hoes to restrain the ever-encroaching weeds and grass. However, when no plowing was possible because of several successive days of rain, the noxious plants were uncontrollable. Something like the terrible creeping and oozing things in horror movies, Bermuda grass, coffeeweed, cocklebur, Johnsongrass, beggar-lice, and nut grass would emerge from what had been a cleanly cultivated field, and in a few days our entire crop of young peanuts and cotton could be submerged in a sea of weeds. Often, despite the most heroic efforts by the best farmers, parts of the crop would have to be abandoned. Although partially salvaged, the remaining young plants were heavily damaged by the aggressive plowing and hoeing. During these rainy times, Daddy would pace at night, scan the western skies for a break in the clouds, and scour the community, often far from our own farm, to recruit any person willing to hoe or pull up weeds for day wages.”

Author: Jimmy Carter
Publication: An Hour Before Daylight: Memories of a Rural Boyhood. 2001. Simon & Schuster, New York.

Herbicide Use Can Increase Bumblebee Populations

Posted on by
Reply

Bumblebees play a crucial role in crop and wildflower pollination. One way to increase bumblebee populations would be to increase the number of wildflowers growing in grassy strips around crop fields. Recent research in the UK has shown that by sowing wildflowers around crop fields where grasses have been suppressed with herbicides, bumblebee populations increase.

“The benefit of applying graminicide [herbicide targeting grasses] was confirmed by a significant increase in sown wildflower cover. This supports previous work showing that graminicide applications can reduce levels of competitive grasses and promote the development of wildflowers.”

“This study has demonstrated that wildflowers can be successfully introduced into existing grass buffer strips when managed with a combination of cultivation, seed and graminicide, producing greater bumblebee abundances than existing conventionally managed strips.”

Authors: Robin J. Blake et al.
Affiliation: Center for Agri-Environmental Research, University of Reading, UK
Title: Enhancing habitat to help the plight of the bumblebee.
Publication: Pest Management Science (2011) 67:377-379.