Tag Archives: America

The Dilemma of Insect Fragments in Processed Tomatoes

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Tomato Fruitworm Damage

Tomato Fruitworm Damage

The tomato fruitworm is the most serious insect pest of tomatoes in the US, feeding on fruit and contaminating it with insect parts, excrement and decay-causing organisms. Interest in spraying insecticides to control the fruitworm was accelerated in the 1930s by the finding of insect fragments in canned products, which were seized and destroyed as adulterated foods by the FDA. Today, insecticides are used to prevent widespread insect damage to tomatoes and tomato shipments for processing are rejected if more than 2% damage is found. Therein is the dilemma. If the standard was relaxed (say to 4%), tomato growers could probably make one less insecticide spray. However, consumers may not want more insect fragments in canned tomatoes and may actually want a tighter standard which would result in more insecticide sprays.

“All loads of processing tomatoes in California are evaluated by inspectors from the Processing Tomato Advisory Board, a marketing order, under the direction of supervising inspectors from the California Department of Food and Agriculture. A load of processing tomatoes is rejected if 2% or more of the tomatoes by weight have a worm or excreta in the flesh of the tomato.

The damage tolerance acceptable to consumers and industry could be changed accordingly. Increasing the tolerance might be expected to result in a reduced number of insecticide applications when used in conjunction with a careful monitoring program.

A reduction in the tolerance might also be considered, arguing that consumers would not tolerate even the present level of insect fragments which, as our results indicate, is possible to have in the final product.”

Authors: Zalom, F. G., and A. Jones.
Affiliation: Department of Entomology, University of California, Davis
Title: insect fragments in processed tomatoes
Source: Journal of Economic Entomology. February, 1994. 87[1]:181-186.

Rice Insect Pest Invades the World from the USA

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Rice Water Weevil Larva

Rice Water Weevil Larva

The home of the rice water weevil is the southeastern US where the species feeds on
grasses in swampy areas. When rice plants were introduced into America, the
insect quickly found this new grass plant to its liking and has been feeding on
rice ever since. The weevils move into rice fields every year from nearby woods
and clumps of grass. Farmers have used insecticides since 1950 to control the
weevil populations in rice fields. The rice water weevil has spread from the
southeastern US to Louisiana, Texas, California, Japan, China and Italy where
it would decrease rice production without insecticide sprays.

“The rice water weevil, Lissorhoptrus oryzophilus, is the most destructive insect pest of rice in the United States. The insect is native to the southeastern United States but has, over the past 60 years, invaded important rice-growing areas in California, Asia and Europe and thus poses a global threat to rice production.

Small-plot research and sampling of commercial fields indicate yield losses from the rice water weevil would likely exceed 10% in many areas if no insecticides are used.”

Authors: Stout, M. J., et al.
Affiliations: Department of Entomology, Louisiana State University.
Title: The influence of rice plant age on susceptibility to the rice water weevil, Lissorhoptrus oryzophilus.
Source: Journal of Applied Entomology. 2013. 137:241-248.

Eastern Filbert Blight Would Kill All the Western Hazelnut Trees Without Fungicide Sprays

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EFB Killing Hazelnut Tree

EFB Killing Hazelnut Tree

Hazelnuts have been commercially produced in Oregon since the early 1900s when they were called “filberts.” In 1981, Oregon “filbert” growers began referring to their crop as “hazelnuts” to be consistent with the rest of the world. Oregon’s hazelnut orchards, concentrated in the Willamette Valley, account for 99% of US production and 5% of world production. Eastern filbert blight is a destructive disease of hazelnut trees that is only present in North America. The disease is known as eastern filbert blight because a shrub harbors the disease in the eastern US. In the 1920s, growers tried to start a hazelnut industry in New York. Filbert blight destroyed the trees. In 1974, the disease was found for the first time in Oregon and has spread throughout the Valley. Without fungicide sprays, the blight would kill the hazelnut trees.

“Eastern filbert blight (EFB) is caused by the fungus Anisogramma anomala…it causes severe perennial cankers, branch die-back, and eventual death of nearly all cultivars of the commercially important European hazelnut, C. avellana. …The pathogen was inadvertently introduced into southwestern Washington in the 1960s and devastated commercial hazelnut orchards because control measures were lacking at the time. It is now widespread across the Willamette Valley of Oregon, where 99% of the U.S. hazelnut crop is produced. Diligent scouting for cankers, extensive pruning, and copious fungicide applications are necessary to continue production in the presence of the fungus.”

Authors: Molnar, T. J., et al.
Affiliation: Department of Plant Biology and Pathology, Rutgers University.
Title: A real-time PCR assay for early detection of eastern filbert blight.
Source: Plant Disease. June 2013. 97[6]:813-818.

National Academy of Sciences Credits Herbicides for Adoption of Conservation Measures in the U.S

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Tillage vs. Herbicides

Tillage vs. Herbicides

In the early 20th century, American farmland was eroding at an alarming rate. The cause of this erosion was continuous plowing of fields to keep weeds out. When herbicides were introduced to control weeds, farmers could reduce tillage. As a result, there have been major reductions in soil erosion in the United States. The National Academy of Sciences has pointed out that this improvement in conserving the soil would not have occurred had it not been for herbicides…..

“The use of herbicides has reduced the need for growers to cultivate to control weeds and that reduction has led to an increase in the practices associated with conservation tillage. These include no-till, ridge-till, strip-till, and mulch-till—practices that leave at least 30% cover after planting. Leaving cover after planting reduces soil loss due to wind and water erosion up to 90%, and it increases crop residue (organic matter) on the soil surfaces up to 40%. Conservation tillage in the United States has increased from 26.1% of the total acreage in 1990 to 37.2% of the total acreage in 1998. Without herbicides, widespread adoption of conservation tillage would likely not have taken place.”

Author: Committee on the Future Role of Pesticides in US Agriculture
Affiliation: National Research Council
Title: The future role of pesticides in US agriculture
Source: Board on Agriculture and Natural Resources and Board on Environmental Studies and Toxicology Commission on Life Sciences. 2000.