问题 问答题 简答题

简述棉铃虫的综合防治技术。

答案

参考答案:

(1)农业防治深翻冬灌减少越冬虫源;麦收后及时中耕灭茬,降低成虫羽化率;提倡棉花与小麦、玉米、油菜等作物间作套种或相邻种植,以丰富天敌资源;结合农事操作,抹卵抓虫灭蛹。种植转B.t.基因抗虫棉;变夏烟为春烟可显著减轻危害。

(2)生物防治在棉铃虫产卵初盛期开始释放赤眼蜂2~3次,每次22.5万头/hm2。在初龄幼虫期喷含100亿活孢子/ml以上的B.t.乳剂300~400倍液或棉铃虫核多角体病毒1000~2000倍液。尽量减少化学农药的施用和改进施药方式,减少杀伤天敌,发挥其对害虫的自然控制作用。也可喷洒25%灭幼脲3号500~1000倍液等防治烟青虫。

(3)诱杀成虫利用黑光灯、高压汞灯、杨树枝把及性诱芯诱杀。

(4)化学防治药剂防治要掌握在3龄前进行。防治2代时,主要喷洒在棉株上部嫩叶和顶尖上,“划圈点点”。第3、4代要喷洒在群尖和幼蕾上,四周打透。可用药剂:50%辛硫磷EC、25%喹硫磷EC,2.5%溴氰菊酯EC、10%氯氰菊酯、5%高效氯氰菊酯以及2.5%功夫EC,24%灭多威或35%硫丹。可用的无公害农药有5%定虫隆EC、5%氟虫脲EC或20%除虫脲悬浮剂。

阅读理解与欣赏
阅读理解

When I was about 10, I was walking down the street with my mother. She stopped to speak to Mr. Lee. I knew I could see Mr. Lee anytime around the neighborhood, so I just stood there. After we passed him, my mother stopped and said something unforgettable, "You let that be the last time you ever walk by somebody you know without opening your mouth to speak, because even a dog can wag its tail when it passes you on the street. "That sentence sounds simple but it made me become who I am.

At work, I used to say hello to the president of the company and ask him how our business was doing. But I also spoke to the people in the cafe and people who cleaned the buildings, and asked them how their children were doing, for every single person deserves to be accepted, no matter how humble(低微的)they are. I remember that after a few years of passing by the president, I had the courage to ask him for a chat. We had a great talk. At some point, when I asked him how far he thought I could go in his company, he said that if I wanted to, I could get all the way to his seat.

I've become vice-president, but that hasn't changed how I treat people. I speak to people wherever I am. Speaking to people creates a pathway into their world, and it lets them come into mine, too.

The day you speak to someone who has his head down and then see him lift it up and smile, you will realize how powerful it is just to open your mouth and say hello.

小题1:What is the best title for this passage?

A.The power of being talkative

B.My mother's influence on me

C.The power of saying hello

D.My way to become vice-president小题2: It is implied in the first paragraph that        .

A.the writer didn't like Mr. Lee

B.the writer didn't say hello to Mr. Lee on that occasion

C.the writer didn't get along well with his mother

D.the writer's mother stopped to say hello to everyone she met小题3: What can we learn from the second paragraph?

A.The writer didn't say hello to everyone in the company.

B.The writer made a very good impression on the president of the company.

C.The president of the company thought the writer was much better than him.

D.The president of the company actually didn't like the writer at all.小题4:For the writer, saying hello to others          .

A.is a way to get what he wants

B.has become a habit and a way of life

C.is a way to show respect for his mother

D.is important in making him remembered小题5:According to Paragraph 3, in the writer’s opinion, speaking to others can       .

A.make our world much better

B.make people much happier every day

C.help people understand each other better

D.help people work much better