Tag Archives: weeds

Global Warming Likely to Result in Increased Insecticide Sprays in the Northeast

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# of Insecticide Sprays for Sweet Corn (Today)

# of Insecticide Sprays for Sweet Corn (Today)

The U.S. is likely to warm substantially over the next 40 years. Along the eastern seaboard, average temperatures will increase in a northward direction. Future temperatures in New York State will be similar to current temperatures in the Carolinas. Increased temperatures and earlier onset of the growing season will reduce the winter mortality of insects, increase the rate of insect growth and increase the number of generations during the crop season. In response, insecticide applications are likely to increase in the northeast-a point recently made in a major climate change report from USDA.

“A warming trend is likely to lead to increased pesticide use in the Northeast due to earlier arrival of migratory insects, higher winter-time survival of insects that currently are only marginally adapted to the region, and more generations of insects within a single season.

With more pests shifting northward, generation times decreasing, and abundances increasing in the future, management costs are expected to increase due to more frequent application of pesticides. For example, pesticide applications to control lepidopteran pests (e.g., moths) on sweet corn decrease with increase in latitude from 15 to 32 times per year in Florida, four to eight times per year in Delaware, and zero to five times per year in New York. “

Author(s): Walthall, C.L., et al.
Affiliation: USDA
Title: Climate change and agriculture in the United States: effects and adaptation
Source: USDA, February 2013. Available at: http://www.usda.gov/oce/climate_change/effects.htm

Southern California Vineyards Recover Thanks to Insecticide Applications

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Grapevines Destroyed in 1999

Grapevines Destroyed in 1999

Temecula Today

Temecula Today

In 1999, about one-third of the vineyards in Temecula Valley, Riverside County, California were destroyed due to Pierce’s Disease which is caused by a bacteria transmitted to grapevines by an insect-the glassy winged sharpshooter. The disease seemed destined to spread throughout Southern California. However, research demonstrated that a carefully-timed insecticide application would prevent the sharpshooter from transmitting the disease to grapevines. As a result of this insecticide use, the wine grape industry in Southern California has recovered and is prospering.

“Twelve years ago a Pierce’s disease epidemic in Southern California wine grapes prompted a multi-pronged local, state and federal attack to contain the disease spread and find a cure or treatment.

Riverside County agriculture officials declared a local emergency in 1999 and 300 acres of Temecula wine grape vines were destroyed after they were found to be infested with the glassy winged sharpshooter.

Emergencies were declared, a task force was formed, and in 2000 $22.3 million in federal financial assistance was secured to reduce pest infestations and support research.

Research found that the Southern California epidemics were almost entirely the result of vine-to-vine transmission…. A protocol of applying one carefully timed application of a persistent systemic insecticide such as imidacloprid virtually eliminates the vine-to-vine spread.

Ben Drake is a Temecula-area wine grape grower and vineyard manager who began seeing problems from PD in the Temecula Valley as early as 1997.

We’ve found that if we apply (imidacloprid) at the middle to the end of May, before the sharpshooter moves out of the citrus and goes into the vineyards, we get levels of the material into the plant high enough that when the sharpshooter flies over from the citrus groves to try it, they just fly back where they came from. Or, if they feed long enough, it will kill them.

But just look at the Temecula Valley now to understand what’s changed: From 12 wineries in 1999, the Temecula Valley Winegrowers Association website today lists more than 50 growers and 34 wineries…. A thriving agritourism industry has developed…. Existing wineries are expanding and new ones are under construction or in planning phases.”

Author: Christine Thompson
Affiliation: Reporter
Title: Grape growers urged to remain vigilant against sharpshooter pest
Source: Western Farm Press. 2011-12-12. Available at: http://westernfarmpress.com/grapes/grape-growers-urged-remain-vigilant-against-sharpshooter-pest

Non-chemical Weed Control Methods Fail to Control Weeds in Organic Peanut Trials

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Extensive research has been undertaken in Georgia to determine the effectiveness of non-chemical weed control methods for organic production systems. None of the systems has proven effective, meaning that hundreds of hours of hand weeding are necessary to make these peanut fields viable.

“The inability to sustain a reliable domestic supply of organic peanut is partially due to difficult and costly weed control. … The initial attempt to develop weed management systems using propane flaming and [Organic Materials Research Institute] OMRI herbicides in organic peanut was a weed control failure. Propane flaming and OMRI herbicides did not control annual grasses and perennial nutsedges, and provided only short-term control of dicot weeds.”

“A factor that limits successful in-row weed control using cultivation is inconsistent performance. … The lack of consistency using cultivation as the primary means of weed control in organic peanut appears to be a major unresolved challenge. Even when cultivator implements are properly adjusted and operated in a timely manner, in-row weeds can escape control. …hand weeding cannot be completely replaced by intensive in-row cultivation. … This is also shown by the time and cost of hand weeding to control escapes, particularly the brush-hoe cultivator at VE/1 wk in 2009 needing 116 hours/ha to remove escapes at a cost of $1,021/ha.”

Authors: W.C. Johnson1, M.A. Boudreau2 and J.W. Davis2
Affiliation: 1USDA-ARS, 2University of Georgia
Title: Implements and cultivation frequency to improve in-row weed control in organic peanut production.
Publication: Weed Technology. 2012. 26(2):334-340.

Herbicides Have Helped Stabilize Wheat Production in Kazakhstan

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Kazakhstan ranks in the top 10-15 wheat-producing countries in the world depending on weather conditions (drought is a significant factor 2 out of 5 years). Kazakhstan is a major exporter of wheat with about 4 million tons exported annually. Weeds are a key limiting factor in Kazakhstan’s wheat production; however, recent increases in herbicide use have significantly reduced yield losses.

“Although weather remains the single most important determinant for grain yield in Kazakhstan, improvements in crop management practices fueled by the growing State subsidies have contributed to the recent increase and relative stabilization in wheat yield.”

“According to specialists at the Ministry of Agriculture, nearly half the total cultivated area in Kazakhstan is infested with weeds, including 2.5 million hectares infested with black oats. Between 1999 and 2002, farmers applied virtually no herbicides for the control of black oats on approximately 320,000 hectares. In 2003, treatment expanded to 1.0 million hectares thanks to government subsidies of about US$2 million which reduced farmers’ cost of chemicals by 30 to 40 percent. Herbicide subsidies increased to nearly US$3 million in 2004 and the treated area grew to about 1.4 million hectares. Specialists report that weed infestation has decreased by about 15 percent every year since the anti-black oat campaign was launched.”

Author: Mark Lindeman
Affiliation: USDA Foreign Agricultural Service
Title: Kazakhstan Wheat Production: An Overview
Available at: http://www.fas.usda.gov/pecad2/highlights/2005/03/Kazakh_Ag/index.htm

New Rice Planting Method Makes Herbicides Necessary in Pakistan

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Traditionally, rice has been planted manually in flooded fields in Pakistan. This method of planting requires large amounts of water and a high level of labor. The sustainability of this system is threatened by severe labor and water shortages. Research has focused on direct machine planting of rice seeds in non-flooded soil. However, weeds flourish when the soil is not flooded making herbicides a necessary component of the new planting system.

“An increasing water crisis, as well as the unavailability and high cost of labor, in Pakistan has forced rice-growers to plant rice directly into the field. However, severe weed infestation causes disastrous effects on the productivity of this rice system. In this study, three herbicides were evaluated for weed control in direct-planted rice on a sandy loam soil. Weedy check and weed-free plots were established for comparison. Weed infestation decreased the rice yield by 75.2%. However, the application of herbicides suppressed the weed infestation, with a simultaneous increase in the rice yield.” 

Author: Khawar Jabran, et al.
Affiliation: Ayub Agricultural Research Institute, Faisalabad, Pakistan
Title: Application of bispyribac-sodium provides effective weed control in direct-planted rice on a sandy loam soil.
Publication: Weed Biology and Management. 2012. 12:136-145.

Mr Bittman, Reducing Herbicide Use on Farms is Not Simple

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The New York Times writer Mark Bittman writes glowingly about a recent study¹ that reported on an Iowa experiment in which crop yields were maintained while herbicides to control weed populations were reduced (“A Simple Fix for Farming,” NYT,10-21-2012)². Bittman concludes that, “there was only upside—and no downside at all” in this study.  Rhetorically, Bittman asks, “Why wouldn’t a farmer go this route?”. That question was studied by rural sociologists from the University of Missouri and their findings³ show that it’s not so simple to reduce herbicide use—there are serious downsides. The study that Bittman cites reduced herbicide use by switching from spraying the entire field (broadcast spraying) to spraying just down the row of plants (banded spraying) and using cultivation to kill weeds between the rows. This technique of “banding” the herbicide spray in combination with tillage was widely-used several decades ago, but farmers changed to spraying the entire field without the need to cultivate. The sociologists asked farmers why they abandoned the practice and if they would consider using it again. The answer was…

“Operators are not rejecting the practice due to a perceived lack of knowledge of how the practice works or dissatisfaction with reductions of pesticide use or of water quality risks. … The reasons for discontinuing banding related to difficulties of implementing and maintaining the practice and consequently, potential negative impacts on yields and profits. Banding requires two major tasks—the initial banding and the subsequent two (or sometimes three) cultivations between the rows. In effect, it substitutes time, labor, and equipment for out-of-pocket pesticide costs and thus has important ripple effects in terms of time, labor, management, flexibility, and individual control.”

“Banding tasks need to be done on a timely basis; a shortage of labor during windows of cultivation opportunity can mean the growth of weeds to the point where they inhibit crop progress and effective cultivation, and thus decrease yields. Some operators report inabilities to find labor. We have ample evidence of the decline of availability of hired labor in most rural communities… Those people willing to custom cultivate are usually farmers themselves. And home farm demands, overextended commitments, and bad weather and machinery breakdowns can easily combine to delay or postpone custom cultivation beyond optimal periods.”

“Cultivation of large banding acreages requires continuous weeks of effort. Although such commitments were common practice before the broadcast use of herbicides, farmers who rejected banding criticize cultivation as too time-consuming, intrusive into other needed work, ineffective, and certainly one of those jobs they were not eager to resume.”

“Some farmers have purchased banding-related machinery or attempted to experiment with the practice only to find it too difficult to incorporate into tight farming schedules. … Effective cultivation also creates dependency on other external factors. In years with a particularly wet spring and early summer, for example, cultivation has to be postponed.”

“In summary, operators who abandon banding do so not because of water quality issues or lack of knowledge or even additional costs; they drop it because of time and labor requirements, custom labor constraints, loss of control over operations, and potential risks to yield and profitability. … In essence, while banding may work for water quality, it is not working for most farmers.”

¹Authors: A.S. Davis*, J.D. Hillª, C.A. Chaseº, A.M. Johannsº and M. Liebmanº.
Affiliations: *USDA ARS; ªUniversity of Minnesota; ºIowa State University
Title: Increasing cropping system diversity balances productivity, profitability and environmental health.
Publication: PLoS ONE. 2012. 7(10): e47149.

²Author: Mark Bittman
Headline: A Simple Fix For Farming
Publication: The New York Times. October 21, 2012.

³Authors: J.S. Rikoon, R. Vickers and D. Constance
Affiliation: Department of Rural Sociology, University of Missouri-Columbia.
Title: Factors affecting initial use and decisions to abandon banded pesticide applications.
Publication: Agricultural Research to Protect Water Quality Conference Proceedings. 1993. February 21-24, Minneapolis, Minnesota.

Organic Sugar Production in Mauritius Derailed Due to Weed Problems

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Sugarcane is the major crop in Mauritius. Weeds are usually controlled with herbicides. In the early 1990s, three sugar processing firms in Mauritius decided to grow organic sugarcane without the use of herbicides. However, the weed problems led to the curtailment of organic production. At the time of this article’s publication, there was still one organic producer; today, we have discovered there are no organic sugar companies operating in Mauritius.

“Organic sugar production started in Mauritius in 1992 after it was realized that a demand existed in Europe. … As the use of herbicides is not permitted in fields under organic crop production, manual weeding had to be resorted to. In view of the acute labour shortage and the increasing cost of labour, this item was a major contributor to the costs of production and one of the main sources of discouragement for producers who generally do not like to see their fields infested by weeds. Manual weeding is also known to be ineffective.”

“Although alternative methods of weed control exist, they could not be envisaged in the Mauritian context. Using a flame applicator would represent a fire hazard because of the presence of dry trash in the field, and weeding by mechanical means is not convenient because of the rocky nature of the soil. Weed control in the fields under organic cane was therefore not carried out to the same extent as it is in conventionally grown cane. … Owing to these constraints, producers gradually lost interest in organic sugar and only one estate, out of the three originally, is still involved.”

Author: J Deville
Affiliation: Mauritius Sugar Industry Research Institute, Reduit, Mauritius
Title: Organic sugar production – the Mauritian experience.
Publication: Proceedings of the XXIII International Society of Sugar Cane Technologists (ISSCT) Congress. February 22-26, 1999, New Delhi, India.

At Mid-Century, German Crop Production Turned to Herbicides

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In the 1950s and 1960s, as Germany industrialized, millions of workers moved from rural to urban areas and to factory jobs. When people left the farms, weed control technology was desperately needed to replace the major task of hand weeding crop fields. The introduction of herbicides saved German agriculture.

“Weeds cause drastic yield losses in food production, on average 25% in developing countries and 5% in developed countries, despite the control measures practiced. … Weed control is one of the major labour-consuming operations in traditional crop production, amounting from <30 up to about 70% of the total labour input.”

“In Germany, industry needed an increasing number of employees around 1960 and rural people left their fields. When this occurred there was no longer the question about traditional weed control with high labour input, but growing the crop with chemical weed control or no crop at all.”

Author: W. Koch
Affiliation: University of Hohenheim, Stuttgart, Germany
Title: Impact of weeds on developing countries.
Publication: Proceedings of the First International Weed Control Congress. 1992. Melbourne, Australia.

Organic Vegetable Crops Require Thousands of Hours of Weeding by Hand

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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

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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