VOA新闻杂志2024--Unwanted Plants Threaten Crops in North-Central US

Unwanted Plants Threaten Crops in North-Central US

Across the north-central United States, weeds that resist control efforts are worrying farmers. This development is the latest sign that weeds are becoming resistant¹ to chemicals faster than major companies can make new weed-fighting products.

Scientists say that some sorts of weeds are developing resistance to chemicals used to destroy them.

Reuters news agency recently spoke² with more than 20 farmers, scientists, weed specialists and company leaders. The news agency also studied eight research papers published since 2021. The studies described how weeds, including kochia, waterhemp, and giant ragweed, are affecting crops in North Dakota, Iowa, Wisconsin and Minnesota.

Over the last 20 years, chemical companies have reduced the percentage of revenue³ meant for research and development spending. These companies are also introducing fewer products, says AgbioInvestor, a company based in Britain that studies the agricultural chemical industry.

Farmers say their battle with weeds threatens grain and oilseed harvests at a time when growers face inflation⁴ and extreme weather.

"We're in for big problems over the next 10 years for sure," said Ian Heap of the International Survey of Herbicide Resistant Weeds. It is a group of international scientists who work with governments and industry. He added, "We are in for a real shake-up."

The research group has a database⁵ of information on the reduced effectiveness of glyphosate, one of the most common weed-killing chemicals, against 361 weed species⁶, including 180 in the U.S.

These weeds affect corn, soy, sugar beets⁷ and other crops.

Around the world, 21 weeds globally showed resistance to dicamba, the most recent major U.S. chemical, which launched in 2017.

Environmental groups argue that farmers should embrace natural weed-control methods instead of chemicals.

One Kochia plant can spread as many as 30,000 seeds. It can result in yields reduced by up to 70 percent if nothing is done to stop it. That information comes from Take Action, a farmer resource program of the United Soybean Board.

Other issues, including the development of stronger seeds, have pushed overall crop yields higher around the world. But scientists expect weed problems to worsen. Some weeds are even showing resistance the first time they are treated with chemicals.

In Douglas, North Dakota, farmer Bob Finken used dicamba and glyphosate to kill weeds late in the growing season. Neither product completely killed kochia.

"That was really scary," said Finken, age 64. "Each year seems to get a little worse."

Finken had to clear the weeds with harvesting equipment, which risks damaging the machinery⁸.

Other farmers are hiring workers to pull weeds by hand, said Sarah Lovas of GK Technology, an agriculture company.

North Dakota was the largest spring wheat producing state in 2023 and ninth-biggest soybean grower.

Five of North Dakota's 53 counties have confirmed populations of dicamba-resistant kochia. That is only one year after it was first reported in the state, said Joe Ikley of North Dakota State University.

"It's just a matter of time before it hits your farm," said 65-year-old Monte Peterson who grows soybeans near Valley City, North Dakota.

Chemical producers Bayer, Corteva and FMC say longer development and government approval processes have limited new products to combat⁹ weed resistance. Industry leaders also say officials have become stricter about possible environmental and health effects.

The U.S. Environmental Protection Agency (EPA) said standards for approving new herbicides have not changed greatly since 1996. However, the EPA said recent efforts to study the effects of new active ingredients on threatened plants and wildlife have delayed some decisions.

The EPA did not estimate the increased processing time. The agency said it speeds up studies of lower-risk products.

Words in This Story

weed – n. a plant that grows very quickly and covers or kills more desirable plants

shake-up – n. is an important change or series of changes.

yield – n. the amount of something that is produced by a farm

standard – n. an acceptable level of quality or achievement; something that is used to judge the quality of something else

1 resistant   

adj.(to)抵抗的，有抵抗力的

参考例句：

• Many pests are resistant to the insecticide.许多害虫对这种杀虫剂有抵抗力。
• They imposed their government by force on the resistant population.他们以武力把自己的统治强加在持反抗态度的人民头上。

2 spoke   

n.（车轮的）辐条；轮辐；破坏某人的计划；阻挠某人的行动 v.讲，谈（speak的过去式）；说；演说；从某种观点来说

参考例句：

• They sourced the spoke nuts from our company.他们的轮辐螺帽是从我们公司获得的。
• The spokes of a wheel are the bars that connect the outer ring to the centre.辐条是轮子上连接外圈与中心的条棒。

3 revenue   

n.总收入，财政收入，税收；税务局

参考例句：

• The country diminished the revenue by reducing tax.这个国家通过减税而使税收减少了。
• A government's revenue and expenditure should be balanced.政府的财政收入和支出要平衡。

4 inflation   

n.胀大，夸张，通货膨胀

参考例句：

• Gold prices are often seen as an indicator of inflation.黃金价格常常被看作是通货膨胀的指标。
• The inflation of the airbed took several minutes.给空气床垫充气花了几分钟时间。

5 database   

n.数据库 （=databank）

参考例句：

• I discovered some new information in the database.我在资料库里发现了一些新信息。
• We planned to build an online database.我们计划建一个联机数据库。

6 species   

n.物种，种群

参考例句：

• Are we the only thinking species in the whole of creation?我们是万物中惟一有思想的物种吗？
• This species of bird now exists only in Africa.这种鸟现在只存在于非洲。

7 beets   

甜菜( beet的名词复数 )； 甜菜根； （因愤怒、难堪或觉得热而）脸红

参考例句：

• Beets are Hank's favorite vegetable. 甜菜根是汉克最爱吃的蔬菜。
• In this enlargement, barley, alfalfa, and sugar beets can be differentiated. 在这张放大的照片上，大麦，苜蓿和甜菜都能被区分开。

8 machinery   

n.(总称)机械，机器；机构

参考例句：

• Has the machinery been put up ready for the broadcast?广播器材安装完毕了吗？
• Machinery ought to be well maintained all the time.机器应该随时注意维护。

9 combat   

n.战斗，斗争，格斗；vt.与...斗争，与...战斗

参考例句：

• The police are now using computers to help combat crime.警方现在使用电脑打击犯罪活动。
• A reporter interviewed the combat hero.记者访问了这位战斗英雄。