Strawberry Fields Forever? Thanks to Fungicides

Strawberry Yields: UK

Strawberry Yields: UK

Strawberry cultivation in the UK reached 13000 hectares by 1924. While the area today is just one-third of the 1924 area, strawberry production has more than doubled due to yield per hectare increasing 5-6 fold. A major factor in increased strawberry yields in the UK has been the increased use and variety of fungicides used.

“The second productivist practice was the increased use of plant protection products from the 1960s. In 1965, up to 11% of the strawberry crops were not sprayed with pesticides; this figure had decreased to less than 2% by 2006. The spray area for fungicides also increased, from 6058 ha in 1965 to 45,960 ha in 2006. This is higher than the area of land cultivated for strawberries since it takes into account multiple sprays per season. The increased use of pesticides during this phase contributed to increasing yields, by decreasing disease pressure. This also had an impact on reducing yearly variations in yield, as pesticides enabled growers to reduce the impact of weather on their crop by reducing disease incidence.”

Authors: Calleja, E. J., et al.
Affiliation: University of Warwick, UK.
Title: Agricultural change and the rise of the British strawberry industry, 1920-2009.
Source: Journal of Rural Studies. 2012. 28:603-611.

Herbicide Use in Finland Promoted by the Government in the 1960s

Herbicide Spraying in Finland 1960

Herbicide Spraying in Finland 1960s

Farmers in Finland were slow in adopting herbicide use in the 1950s with only 12% of the acreage treated and fields were overrun with weeds. The Finnish government launched a national weed control program in the 1960s to promote the use of herbicides and herbicide use increased steadily. Today, more than 95% of cereal crop acres in Finland are treated with herbicides annually.

“In Finland, weeds are of relatively great significance because of the open ditch drainage systems in the fields. After the second world war the problem of weeds assumed an even greater importance owing to the mechanization of plant production. In Finland the use of herbicides was not, however, very prevalent in the 1950’s as in most other agricultural countries.

In view of the above facts a national weed campaign was launched in collaboration with agricultural organizations in 1962. The plan of campaign covered a period of three years. The promotion of the chemical control in cereal crops was the foremost object of the first year. Despite adverse climatic conditions the work proved most successful and the field acreage sprayed with herbicides was doubled, covering finally some 300,000 hectares, corresponding to 28% of the total cereal acreage.”

Author: Mukula, J.
Affiliation: Department of Plant Husbandry, Tikkurila, Finland.
Title: National weed campaign of 1962.
Source: Maatal ja Koetoum. 1963. 17:192-200.

Insecticides Required to Meet Consumer Demands for Blemish-Free Carrots in the EU

nasty carrots

Carrot Fly Damage

Carrot is one of the most important vegetable crops in the EU with 6 billion pounds of annual production. The carrot fly is the major insect pest of the carrot crop in Europe. Before the introduction of insecticides in the 1950s, the carrot fly typically damaged 20-50% of the carrots grown in Europe. In some parts of Europe, the damage from the carrot fly was so severe that it was not profitable to grow carrots. Today, European carrot growers spray insecticides to prevent damage from the carrot fly.

“Carrot fly, is the most widespread and serious pest of carrot, parsnip, parsley and certain other umbelliferous herbs in temperate regions of the world. … The insect has two and, in some parts of Britain, Europe and New Zealand, three generations each year. Adult insects feed on the nectar and pollen provided by flowers and spend most of their life in the hedgerows, ditches or amongst herbaceous plants in gardens. Females search out carrot plants to lay their eggs which are inserted in crevices around the crown of the host plant. The larvae, which emerge from the eggs, migrate downwards to feed on plant roots.

Carrots grown commercially can be rendered unmarketable by even slight carrot fly damage.

To meet the stringent levels of blemish-free produce demanded by the supermarkets in the UK and Europe, commercial carrot production depends precariously on a few insecticides to control this pest.”

Author: Ellis, P. R.
Affiliation: Horticulture Research International, UK.
Title: The identification and exploitation of resistance in carrots and wild Umbelliferae to the carrot fly, Psila rosae (F.)
Source: Integrated Pest Management Reviews. 1999. 4:259-268.

Exempting Organic Growers from State Spray Program Reduces California Tomato Production

Stunted Tomatoes

Stunted Tomatoes

Beet Curly Top Virus is a viral disease of tomatoes vectored by the sugarbeet leafhopper. In California, leafhoppers overwinter in the foothills and in the spring they migrate down into tomato fields. Since 1943 the California Department of Agriculture has conducted a spray program targeting the leafhopper in the foothills. This spray program has prevented massive losses in tomato fields. However, in recent years organic farming operations in the foothills have been exempt from the spray program. As a result, large populations of leafhoppers have migrated from the unsprayed organic fields into tomato fields with disastrous results.

“Had California’s 2013 tomato crop not been hit so hard by the Beet curly top virus (BCTV) it could have been a banner year for growers.

Bob Gilbertson, plant pathologist with the University of California, Davis, estimates last year’s tomato crop was reduced by about a million tons because of BCTV, which is vectored by the Beet leafhopper.

Tomato plants with BCTV become stunted and develop curled leaves. Upon closer inspection of the undersides of tomato leaves the veins appear swollen and they turn purple, Gilbertson said. Plants also turn a dull green-to-yellow and the fruit is small and tends to ripen prematurely.

Disease transmission begins early in the season as leafhoppers migrate from the foothills to the agricultural valleys, but can also happen during the growing season.

Adult leafhoppers tend to overwinter in the foothills. In the spring the females lay eggs on the green plants in the foothills and acquire the virus during feeding. As new leafhoppers become adults they then migrate to the valley.

The California Department of Food and Agriculture has a curly top spray program where the state sprays the foothills for the Beet leafhopper.

Tomatoes with curly top symptoms began showing up in late March of last year. Losses were the highest in Fresno, Kern and Kings Counties. Yield losses appeared far beyond the western foothills, and even into San Joaquin County.

Why was it so bad?

Gilbertson suspects a combination of favorable conditions for the leafhopper and hosts for the virus in the foothills.

There are limitations on the spray program, which could have helped leafhopper populations thrive.

“The spray program is being constrained now by certain farmers who want to do organic production in the foothills,” he said.”

Author: Fitchette, T.
Affiliation: Reporter.
Title: Virus slams 2013 California tomato yields.
Source: Western Farm Press. 2014-02-12. Available: http://westernfarmpress.com/vegetables/virus-slams-2013-california-tomato-yields?page=4

The Sugarcane Aphid Makes a Mess on Sorghum

2 plants 1 picture

Sugarcane Aphid Damage to Sorghum

Grain sorghum is a billion dollar crop for Texas producers.  A 2013 outbreak of a new invasive pest (the “white” sugarcane aphid) caused from 25-50% loss in some unprotected fields. Infestations were very heavy, often with 100s of aphids per leaf. Leaves became sticky and shiny from aphid excreta and coated with sooty mold fungus, which hampered harvesting operations. Fortunately for 2014, an insecticide is available.

“Calling the current “white” sugarcane aphid outbreak in Deep South Texas a crisis, Texas AgriLife Extension Integrated Pest Management specialist Danielle Sekula-Ortiz is warning Lower Rio Grande Valley sorghum growers to “brace yourself” after scouting sorghum fields this week and warns about the proliferation of the pest in other types of crops.

“Practically overnight we saw a huge jump in aphid population numbers in sorghum fields across parts of the Valley and we are beginning to see movement between sorghum fields and corn and even sugarcane. I have never seen anything blossom this fast,” Sekula-Ortiz said.

Sekula-Ortiz has been warning sorghum growers to scout fields for the new sugarcane aphids, but she says many are still confused over the more traditional yellow sugarcane aphid and this new aphid species.

“Several growers have dealt with the larger yellow sugarcane aphid in the past and have not fully understood this new aphid represents a greater risk.

The good news, if there is any, is that early applications of Dow AgroSciences’ Transform WG are proving to be effective if applied correctly. The downside is an application increases input costs by about $6 an acre. EPA authorized a Section 18 to Texas Department of Agriculture for the use of Transform WG (sulfoxaflor) on sorghum to control the sugarcane aphid.

“We are looking at the need for two applications for adequate control, and maybe a third application depending on the intensity of the problem in individual fields.”

“Some of our larger producers in the Valley decided early on they wouldn’t treat their fields because of the added costs. Some felt like they had weathered past aphid outbreaks, but over the last week or so they are beginning to understand this is not just an average outbreak of the yellow sugarcane aphid but an entirely new threat.””

Author: Hawkes, L.
Affiliation: Reporter.
Title: “White” sugarcane aphid: “brace yourself” warns IPM specialist.
Source: Southwest Farm Press. 2014-05-20. Available: http://southwestfarmpress.com/grains/white-sugarcane-aphid-brace-yourself-warns-ipm-specialist

Yams are in Decline, Herbicides Can Help

yams

yam (left); sweet potato (right)

The dominant zone for yam production in the world is in West Africa, where about 93% of the world’s production occurs. Yam is a major source of calories for millions of people. Yam produces the highest amount of food calories and protein annually per hectare. Currently, yam farming is very labor-intensive and the crop is in decline.

“Weeds pose an increasingly serious challenge in yam cultivation. Speargrass is a noxious rhizomatous perennial weed found especially in the lowland sub-humid zones of West and Central Africa where it severely constrains crop production. …Chemical control reduces speargrass density leading to higher yields.

As far back as 1982 several authors, as summarized by Diehl… predicted a future decline in yam production based on economic and agronomic considerations. The major issues were shortage of labor, in view of the labor intensive nature of yam cultivation… limited availability of seed yams; declining soil fertility associated with reduced fallow periods; and a reported shift in demand to cheaper commodities in some areas.

More recently a mathematical model, based on FAO data, predicted that yam production could decrease dramatically over the next 15 years. They attributed the predicted decline to a combination of high costs of production, inadequate yields, losses in storage and unfavorable prices to farmers.

The cost of labor in yam cultivation (about 40% of total variable cost) is high and increasing. Yam farmers are ageing and have increasing difficulty in coping with the challenges of cultivation. Increasing urbanization is leading to increased labor shortage and cost. Yam production systems will benefit from:

…increased use of mechanization and other labor-saving practices (e.g. use of herbicides).”

Authors: Asiedu, R., and A. Sartie.
Affiliation: International Institute of Tropical Agriculture, Nigeria.
Title: Crops that feed the world 1. yams.
Source: Food Security. 2010. 2:305-315.

Do You Want Nematodes with Your Fries?

potate

Nematode-Damaged Potato

Farmers in Oregon and Washington grow 12 billion pounds of potatoes every year. 90% of this production is for processing into potato chips and fries. 80-90% of the potato acres in Oregon and Washington are fumigated every year to reduce populations of nematodes which are microscopic parasitic worm-like animals that live in the soil and penetrate potatoes underground. Females feed just under the potato skin and deposit 200 to 1000 eggs. Brown spots become evident when the eggs are laid. Growers fumigate the soil to reduce the nematode populations because of the potential for rejection of the potatoes for processing into consumer products.

Columbia root-knot nematode (CRN) infects and develops in potato tubers but does not cause yield loss. Columbia root-knot nematode causes quality defects such as galling on the surface and small brown spots surrounding adult females when peeled. The external and internal defects render tubers unacceptable for fresh market sales and internal defects are unacceptable for processing. For processed potatoes, if between 5% and 15% of the tubers in a field have visual defects the whole-field crop can be substantially devalued or rejected. Based on USDA 2010 yields and prices, the average gross value of potatoes in Idaho was $6,921/ha. The rejection of a potato crop grown on an average 52.6-ha center-pivot-sprinkler-irrigated field represents a loss of $364,000. The potential for dire financial consequences from the presence of CRN in potato tubers is taken very seriously by producers.

Because potential for crop rejection exists with low population levels at planting, fields with any CRN must be treated with a preplant fumigant, nonfumigant nematicides, or both.”

Authors: King, B. A., and J. P. Taberna, Jr.
Affiliation: USDA, Agricultural Research Service, Kimberly, ID
Title: Site-Specific Management of Meloidogyne chitwoodi in Idaho Potatoes Using 1,3-Dichloropropene; Approach, Experiences, and Economics
Source: Journal of Nematology. 2013. 45[3]:202-213.

Brazil: The World’s Future Rice Bowl?

barzil

For the past several years, Brazil has caught much of the attention of the global rice market. The large increase in rice production in Brazil, its expanding share in the international rice markets and its highly valued quality rice have made it recognized as a major player in the global rice market. Herbicides have played a major role in the increase in rice production in Brazil.

“Weedy red rice is one of the main problems in most of the rice-growing regions of the world because it decreases rice grain yield and milling quality. …The development of imidazolinone herbicide–resistant rice cultivars has allowed selective control of weedy red rice in the rice crop. This technology has been used across approximately 1.1 million ha in Brazil and the same area in the United States, and is under development in several countries in South and Central America, Central Europe, and Asia. The use of imidazolinone herbicides on imidazolinone-resistant rice cultivars has improved the control of red rice and led to the adoption of better crop management practices. In Brazil, this system started to be used in 2003, and since 2007 these processes resulted in an increase of approximately 40% in the mean rice grain yield in southern Brazil. Similar benefits have also been observed in other areas where this technology has been used.”

Authors: Goulart, C. G. R., et al.
Affiliations: Federal University of Rio Grande do Sul, Brazil.
Title: Distribution of weedy red rice (Oryza sativa) resistant to imidazolinone herbicides and its relationship to rice cultivars and wild Oryza species.
Source: Weed Science. 2014. 62:280-293.­ Available: http://www.bioone.org/doi/abs/10.1614/WS-D-13-00126.1

Warning: The Risks of NOT Using Herbicides

DOODS

John Nalewaja                                                                             Homer LeBaron

For most people, weeds are usually regarded as innocuous. Controlling weeds with herbicides is practiced on a large-scale every year, largely unnoticed and unappreciated by most people. Scientists who have spent their careers studying weeds (weed scientists) know the potential risks of NOT using herbicides. Two prominent weed scientists have written eloquently about weeds and the importance of herbicides.

“Weeds are the silent, malignant, massive natural force which invades agricultural fields and paddies, spreads to deplete the soil moisture, devours the plant nutrients, and deprives crops of sunlight with severe devastation to crop yields. Weeds endanger the quantity of our food, feed, and fiber and enslave millions of men, women, and children in emerging nations to a laborious life of weeding with primitive methods and tools—machete, sickle, and hoe—just to escape starvation from day to day.”
-Nalewaja, J.D. 1972 [1]

“I maintain that never in history have so few done so much for so many in providing food and improved standard of living as weed scientists.  We have enjoyed a phenomenal success in providing the only consistent, dependable, efficient and economical means of weed control the world has ever known, even leading to surplus production on fewer acres…. We must educate the public and policy makers on the risks of not using herbicides.”
-LeBaron, H.M. 1990 [2]

Authors: [1] Nalewaja, J. D. [2] LeBaron, H. M.
Affiliations: [1] North Dakota State University [2] Syngenta.
Titles: [1] Weeds: coexistence or control. [2] Weed science in the 1990s: will it be forward or in reverse?
Sources: [1] Journal of Environmental Quality. 1972. 1(4):344-349. [2] Weed Technology. 1990. 4:671-689.

In Greece, Spraying Mosquitos Makes Life Bearable

mosqueto

Mosquito Biting Human

Greece has a long history of mosquito-borne diseases (malaria, dengue fever) and there is scientific evidence that some inhabitants have contracted West Nile virus. Especially in Northern Greece where the majority of wetlands and rice fields are located, inhabitants and visitors suffer from an unbearable mosquito nuisance every year for more than 5 months (May – September) and counts of 150-200 mosquito bites per 15 minutes are not unusual. A large-scale mosquito insecticide spray program makes life bearable.

“Wide area mosquito control projects involve survey and applications in natural, agricultural, periurban and urban environment.

A total of about 8,000 sampling stations are established every summer period and checked weekly for larval activity. In addition more than 25,000 private properties (houses and tourist installations) are visited and checked for breeding sites.

The main spraying applications (larviciding) are conducted by four Hiller UE-12E helicopter, and an Ultra Light Motorized (ULM) aircraft. Minor applications are conducted by 15 conventional spraying units, mounted on 4×4 trucks and one low volume fan sprayer unit mounted on a Unimog 4×4 vehicle. For various spot treatments mainly in urban and periurban environment, knapsack sprayers and granule applicators were used.

In total a mean of 100,000 ha are sprayed with larvicides every year. About 80% of this surface is aerially treated. Spraying frequency of rice fields varies considerably from one to five times while this of the natural systems rarely exceeds two times per season.

The positive results of the project are clearly reflected in surveys in the form of questionnaires the company has conducted in 1999 and 2006 in a sample of 1000 inhabitants in 15 communities of the Thessaloniki plain: In 1999 100% of the people considered the mosquito problem unbearable before the beginning of the control project, while 68% considered it medium, small or non-existent after its implementation. In 2006 the results were 48% and 84% respectively.”

Authors: Iatrou, G. and S. Mourelatos.
Affiliation: Ecodevelopment S.A.
Title: Mosquito control in Greece.
Source: International Pest Control. 2007. May/June:66-69.