Opium Poppies Need Pesticide Applications


Opium Poppies

The opium poppy is cultivated in different parts of the world such as Tasmania, India, Pakistan, Slovakia, France, Spain, Yugoslavia and Italy.  The fruits of the poppy are rounded capsules. The liquid (milky latex) obtained after lancing the capsules contains opiates which are dried to produce raw opium, used for processing medicinal drugs such as codeine and morphine. The commercial production of opium poppies is adversely affected by uncontrolled weeds, insects and disease organisms. Commercial growers rely on pesticide applications as described in a recent article about poppy growing in Slovakia.

“The cropping system of poppy has seen important changes in recent years. In the past, growing this crop required a great deal of manual labor connected with singling, hoeing and particularly capsule collecting. At present, all operations of the large scale cropping system, from sowing to harvest, are fully mechanized. Registered pesticides are used to control weeds, diseases and pests.

Pre-emergent herbicides Callisto 480 SC (mesotrione), or Lentipur 500 FW + Command 36 CS (chlortoluron + clomazone) are applied within 3 days after sowing. Due to slow initial growth, the post-emergent application of herbicide in growth phase of 4-6 true leaves is usually necessary.

Protection against poppy root weevil is realized through seed treatment with Cruiser OSR preparation. …A dangerous pest of poppy is poppy weevil, against which the protection is aimed at the time of “hook stage”. Among the registered insecticides, Mospilan 20 SP (acetamiprid) and Nurelle D (chlorpyrifos + cypermethrin) are used.

Poppy downy mildew and poppy fire are considered to be the most dangerous diseases of poppy, in conditions of the Slovak Republic. Occurrence of downy mildew during the leaf rosette period is suppressed by seed treatment. …In the phase of stem elongation, application of Acrobat MZ WG (dimethomorph +mancozeb) is possible. In the “hook stage”, Discus (kresoxym-methyl) or Bumper Super (prochloraz + propiconazole) are used to suppress poppy fire on both leaves and capsules.”

Names: Fejer, J., and I. Salamon.
Affiliation: Presov University in Presov.
Title: Agro-Technology of the Poppy: Large-Scale Cultivation in Slovakia.
Source: Acta Hort. 2014. 1036:181-186.

Imagine Biting Into A Pickle and Finding a Worm

Pickle Worms

Pickle Worms

Farmers in Florida, South Carolina and North Carolina grow 250 million pounds of cucumbers each year which are processed into pickles. The most troublesome insect pest on cucumbers in these states is the pickleworm. The pickleworm is a tropical pest and lives year-round in Florida and moves up the coast in the summer. Each female lays about 350 eggs on cucumber and related plants. The pickleworm larvae bore into the cucumbers where they eat out a large cavity which is contaminated with the worm’s excrement. Frequent insecticide sprays are needed to prevent the pickleworm from entering and contaminating pickles.

“A major insect problem, pickleworms follow spring north each year to lay eggs in the 50,000 acres of cucumbers in North and South Carolina. As summer progresses, the insect becomes a problem in states farther north.

The adult pickleworm moths lay eggs in the fields. Larvae hatch and eat their way into young cucumbers.

Growers start spraying their fields with potent pesticides almost every week for the moths’ 6- to 7-week season as soon as the nighttime temperature reaches 60°F—the temperature the moths follow north.

Why the worm witch hunt? It’s because pickle packers will refuse to accept a truckload of cucumbers if they notice even one with a pickleworm hole. (Understandably enough—imagine biting into a pickle and finding…)”

Author: Kaplan, K.
Affiliation: ARS.
Title: Less Pickleworm Pesticide.
Source: Agricultural Research. 1989. June.

Asparagus Ferns Need Fungicide Protection

desert ferns

Asparagus Ferns

Asparagus is a perennial crop that should have a productive life of 15 or more years. Asparagus spears grow upward through the soil from underground crowns. The spears are cut by hand every 2-5 days. After two to three months, spear harvest ceases and the spears are allowed to grow into ferns with a thick canopy of feathery leaves. During the fern stage, the plant produces and stores energy for the following year’s crop. Purple spot on asparagus was first reported in the U. S. in 1981. The main damage from purple spot is on fern growth. Fungal damage to the ferns results in defoliation of the needles which reduces the flow of carbohydrates to the roots and lowers next years yield.

“Purple spot of asparagus is an important fungal disease in many growing regions including Michigan, California, Washington, England, and New Zealand. The fungus overwinters as pseudothecia on the surface of asparagus fern debris and releases ascospores as primary inoculum in the spring.

Purplish lesions may subsequently develop on the spears, making them commercially unacceptable, especially for the fresh market… Following infection, tan to brown lesions may develop on the fern and premature defoliation may occur. Premature defoliation of the fern limits its photosynthetic ability, resulting in decreased carbohydrate reserves for the crown that may negatively affect yields in the following years.

Growers apply fungicides to manage purple spot on the fern after the last spears are harvested; fungicides are not applied to asparagus spears that will be harvested.”

Authors: Granke, L. L., and M. K. Hausbeck.
Affiliation: Department of Plant Pathology, Michigan State University
Title: Influence of Environment on Airborne Spore Concentrations and Severity of Asparagus Purple Spot.
Source: Plant Disease. 2010. 94[7]:843-850.

Pesticide Guy Signing Off

Pesticide Guy’s last blog post will be posted on December 30 and that will be it. I have truly enjoyed sending out the almost 300 messages on the worldwide benefits of pesticides. I think that I met my objective of providing a broad set of scientific documentation on this topic. Pesticide Guy has been accessed over 26,000 times. The set of Pesticide Guy blog posts will continue to be available on the WordPress website and can be searched for individual topics indefinitely.

New Insecticides Greatly Improve Grape Insect Management


The grape berry moth is an annual problem on about 50% of the grape acres around the Great Lakes in New York, Ohio, Pennsylvania and Michigan. Females glue their eggs on the berries and larvae hatch out and feed in the berries. Insecticides have been used for 100 years to control the grape berry moth and reduce the infestation from 24-30% to less than 1%. Until recently, broad-spectrum insecticides with long residuals were used to manage grape berry moth. However, new insecticides have been registered and they provide tremendous opportunities to selectively manage insect pests in grape vineyards.

“The past 10 years has seen a dramatic change in the spectrum of insecticides available for grape producers, with new modes of action and pest spectra allowing an unparalleled opportunity for growers to target specific pests for control while also minimizing the risk to non-target organisms.

There is now increased potential for realizing integrated control, since many of the most effective new insecticides have been evaluated and shown to have relatively low impact on natural enemies. For example, registration of the insect growth regulator insecticides methoxyfenozide and diflubenzuron for use in vineyards and the recent availability of the diamide insecticdes rynaxapyr and flubendiamide allow more selective and long-lasting control of lepidopteran pests without high levels of natural enemy mortality.

Acaricides have also changed from broad-spectrum to more selective chemistries. The vineyard manager now has an array of different acaricide modes of action available, many of which can selectively kill pest mites without injuring predatory species. Some of these are also systemic, thereby providing a route of exposure that further protects predators from direct contact with the acaricide.”

Authors: Isaacs, R., et al.
Affiliation: Department of Entomology, Michigan State University
Title: Vineyard IPM in a changing world: adapting to new pests, tactics, and challenges.
Source: Anthropod Management in Vineyards: Pests, Approaches, and Future Directions. 2012. Springer. Pgs. 475-480.

100 years of Fungicide Protection Against Brown Rot of Stone Fruit

Brown Rot on Peach

Brown Rot on Peach

The brown rot fungus infects all the acres of cherries, peaches and nectarines in the U. S. Ash-gray masses of millions of spores appear on the fruit and the fruit becomes completely rotten and soft within a few days. Brown rot caused substantial fruit losses before the development of fungicides. Most peach growers expected to lose 50-75% of their crop. With the development of a finely-powdered sulfur fungicide about 1912, stone fruit growers began widespread spraying to control brown rot. This spraying has continued to this day.

“Who does not love the delicious taste of fresh peaches, nectarines, plums, apricots, or cherries? Because of their popularity, stone fruits are grown all over the world, but it is not only consumers who like these tasty fruits. Some fungi have specialized in infecting and colonizing stone fruits wherever they are grown. 

There are ways to reduce disease pressure in commercial orchards, including the removal of fruit mummies from the tree canopy, pruning out cankers and removal of wild plums surrounding orchards. However, these measures do not prevent brown rot disease, and growers are still dependent on the application of fungicides for blossom blight and pre- and postharvest disease management.”

Authors: Schnabel, G., et al.
Affiliation: Clemson University.
Title: Sustainable brown rot management of peaches in the southeastern United States.
Source: Outlooks on Pest Management. 2010. October. Pgs. 208-211.

Fungicide Spraying is Critical for African Potato Production

African Potato Fields Fungicide Treated (L) Untreated (R)

African Potato Fields Fungicide Treated (L) Untreated (R)

Potato consumption has increased dramatically in Sub-Saharan Africa in the past ten years as more people have moved to cities and have diversified their diets. Potato production has increased to meet the demand through the planting of more fields with potatoes which are encroaching on forestland. Potato yields remain low in Africa primarily due to damage from the late blight disease. Increasing farmer knowledge about late blight and the importance of fungicide recommendations could dramatically increase potato yields.

“Potato cultivars grown in Uganda have low levels of general resistance to late blight. As such, most commercial potato farmers rely on fungicide applications for control of Phytophthora infestans, the causal agent of late blight.

Potato has become an important staple and cash crop in the highlands of eastern Africa. These areas experience moderate temperatures (about 15–22°C) and receive relatively high amounts of rainfall (>1200 mm per year) that are favourable for potato production. However, these same conditions favour severe epidemics of late blight, and as such, late blight is a major limitation to potato production in high humid elevations.

In Uganda, potato late blight has been a serious problem since the introduction of the crop into the country in the early 1900s… During the 1990s, six varieties with resistance to late blight were released. However, resistance to late blight in these cultivars has since been overcome and significant yield losses experienced. Additionally, susceptible varieties are still greatly desired by farmers due to their good agronomic characteristics. Invariably, fungicides must be used to ensure disease control.”

Authors: Kankwatsa, P., et al.
Affiliation: Department of Crop Science, Makerere University, Uganda.
Title: Efficacy of different fungicide spray schedules for control of potato late blight in Southwestern Uganda.
Source: Crop Protection. 2003. 22:545-552.

Control of Cherry Maggots Has Become Very Difficult in the E.U.

Churry Maggots

Cherry Maggots

Adult cherry maggot flies deposit eggs under the skin of the fruit and the hatched maggots feed inside the berry. There is zero tolerance for maggot-infested cherries in the marketplace and insecticides have been used for over 100 years. However, in the E.U. with increased restrictions on insecticides and lack of newly-registered products, control of cherry maggots has become problematic.

“The European cherry fruit fly, Rhagoletis cerasi L. (Diptera: Tephritidae) is the major insect pest of sweet and tart cherries throughout Europe, infesting up to 90% of fruit in untreated sites. A great need has arisen for effective control techniques because of an almost zero tolerance of infested fruit in the fresh market, notwithstanding an agreed economic threshold of 2% infestation. Cherry fruit fly control in the European Union (EU) has recently become very difficult as a result of programmes to reduce the use of broad-spectrum insecticides, for reasons of environmental and human safety. Such withdrawals of insecticides have occurred in the absence of identified alternatives for R. cerasi. In Germany, its management is currently achieved by the application of systemic insecticides (e.g. acetamiprid, dimethoate), authorized by special permits and, for dimethoate, with many restrictions on use.”

Authors: Bockmann, E., et al.
Affiliation: Institute for Plant Protection in Fruit Crops and Viticulture, Germany.
Title: Bait spray for control of European cherry fruit fly: an appraisal based on semi-field and field studies.
Source: Pest Management Science. 2014. 70:502-509.

High Taxes in the E.U. Will Not Reduce Pesticide Use: Pesticides are Essential


Dutch Farm

Pesticide use is very high in the E.U. and policies to reduce use have been adopted. Under consideration are taxes on pesticides. Some people believe that pesticides are not essential and that alternatives are available and, as a result, believe that taxes would cause farmers to reduce their use of pesticides. However, recent research in the Netherlands shows that, due to their essential importance, pesticide use is unlikely to go down even with very high taxes. The main effect of high taxes on pesticides would be to reduce farmer income.

“Pesticides are integral components of modern crop production systems. Recently, attention is focused on the use of economic incentives to reduce pesticide use and its related indirect effects. The European Union’s (EU) pesticide policy envisages the use of pesticide tax and levy schemes.

The aim of this study is to assess the effectiveness of different fiscal measures in reducing pesticide use and environmental spillovers by using detailed farm-level data from Dutch arable crop production.

Increasing the tax rate (for both high- and low-toxicity products) to 80% and 120%, total pesticide use is decreased by almost 3% and 4%, respectively. These scenarios show that even high taxes are not able to achieve significant reductions in pesticide use. Moreover, high taxes decrease farm revenues as the 4% pesticide decrease is accompanied by a 22% decrease in farm revenue. Producers’ rigidity in reducing pesticide use, thus avoiding the tax burden, may be attributed to the damage preventing role of pesticides and their capacity to reduce output variability.

The dilemma inherent in pesticide taxation is that the use of pesticides may be so essential for some crops or regions that tax rates would have to be very high to impact pesticide use. This could result in a major reduction in farm income as depicted through the pesticide tax scenarios presented in this work… Results show that even high (and politically challenging) tax rates would result in a small reduction in the use of pesticides due to the rigidity of Dutch farmers in reducing pesticide use.”

Authors: Skevas, T., et al.
Affiliation: Wageningen University
Title: Can economic incentives encourage actual reductions in pesticide use and environmental spillovers?
Source: Agricultural Economics. 2012. 43:267-276.

Herbicide Adoption Contributed Greatly to Increased Corn Production


Corn yields tripled in the U.S. between the 1930s and 1980s. Many new technologies and practices contributed to this increase in corn yields: hybrids, fertilizers, herbicides, insecticides, increased plant populations, early planting. A researcher at the University of Minnesota studied all of these factors to determine their contribution to the increase and determined that herbicides contributed about ¼ of the increase due to better weed control.

“Corn (Zea mays L.) yields in Minnesota have increased from the 2,010 kg/ha yield level of the pre-1930’s to the current 6,290 kg/ha average. This increased yield can be attributed to a series of technological, cultural, and management practices adopted by farmers. My objective is to attempt an analysis of the magnitude of the changes and the relative contributions to grain yield each practice has made over the 50-year time period.

Improved weed control by the use of herbicides on 93% of the hectarage has increased yields 23%.”

Author: Cardwell, V. B.
Affiliation: University of Minnesota, St. Paul.
Title: Fifty years of Minnesota corn production: sources of yield increase.
Source: Agronomy Journal. 1982. 74[November-December]:984-990.