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New ways to improve crops, control insects

 

New ways to improve crops, control insects Listen to this story

I'm Gwen Outen with the VOA Special English Agriculture Report.

Agriculture scientists are continually looking for new ways to improve crops, control insects and reduce the need for chemicals. It is a never-ending search. It often results in finding a solution for one problem while making another problem worse. Sometimes, however, farmers can solve several problems at the same time. They can do this by carefully choosing the crops they plant in the same field.

In the early nineteen nineties, the magazine Organic Gardening from the Rodale Institute published some studies on this subject. There was advice from a scientist named Kimberlyi Stoner, an insect expert at the Connecticut Agriculture Experiment Station. She said farmers can keep flea beetles out of abroccolifields by plantingcloverin the same field. Flea beetles cannot find broccoli when it is surrounded by clover. So the insect flies away in search of a broccoli that it is growing in a field without clover.

Another method of protecting the main crop is to plant it in the same field with some plants that insects do not like. For example, the Colorado potato beetle does not liketansybecause of the strong smell of this herb. So researchers at Rodale Institute planted tansy in several potato fields. The population of Colorado potato beetles was reduced anywhere from 60 to 100 percent. The reduction depended on the amount of tansy planted. Studies done later in a laboratory showed that tansy produces a natural chemical that keeps the potato beetle at a distance.

In fact, some insects like weeds more than they like crop plants. Scientists did some research at the subtropical cordon insects research station in Texas. They plantedragweedandpigweedin a field of bell peppers. Leaf manor insects can destroy a bell peppers crop. But when given a choice of bell peppers or ragweed and pigweed, the insects chose the weeds.

In another experiment, researchers in India planted cabbage and master greens in the same field. They were attempting to controldiamondbackmoss and leaf Webers. In three sub tests, the insects chose the master greens instead of the main crop, the cabbage.

Next week we will discuss how some plants how be each other through their roots systems. And we will discuss how some plants attract helpful insects that feed on harmful insects.

This VOA Special English Agriculture Report was written by Bob Bowen. I'm Gwen Outen.

Vocabulary:

broccoli: 花椰菜

clover: 三叶草,苜蓿

tansy: 艾菊

ragweed:豚草,豚草属的杂草,有绿色、雌雄合一的小花冠,能产大量花粉,是引起干草热的主要原因之一

pigweed: 苋(藜属),一种普通野草,长有叶面有花斑的长矛状叶子,开有绿色的小花

diamondback: 有菱形斑纹的

 
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