With the popularization of rice light cultivation techniques and the change of farming system, the occurrence and harm of arrowheads in rice fields are becoming more and more serious. In some rice fields, the arrow can reach half a meter or even one meter high. After the wild arrowheads appear more, they will cover the rice and compete for nutritious rice, which will seriously reduce production. What are the prevention and treatment techniques of sagittarius?

(A) the use of agronomic measures to control arrows

The growth of Sagittarius sagittarius is highly dependent on water, and the spread and harm of Sagittarius sagittarius can be controlled to some extent by adopting modern rice water-saving cultivation techniques. Rice seedling stage is mainly irrigated by alternating dry and wet irrigation, and the field water is drained and put aside after tillering stage; When rice enters the reproductive growth period, shallow water and moist irrigation are the main methods; Single-season rice and double-season late rice should be drained and roasted immediately after maturity, and the supply of field water should be controlled to the amount needed for rice growth to avoid flooding throughout the growth period.

After harvesting single-season rice and double-season late rice, ploughing the serious fields of Sagittarius in autumn, so that some underground bulbs of Sagittarius can be ploughed to the soil surface. After drought and sun exposure, the underground bulbs of Sagittarius sagittarius will lose their ability to germinate and reproduce, thus reducing the number of Sagittarius sagittarius bulbs in the soil in the second year.

Paddy-upland rotation is an effective measure to control sagittarius. After planting rice for many years, we switched to dry crops such as soybeans, corn and cotton. In the arid farmland, Sagittarius Sagittarius's underground bulbs can't get enough water, lose their germination ability and die soon. When the arrowhead bulbs in the soil are greatly reduced, rice can be rotated.

(b) Use chemical herbicides to control arrows.

1. Herbicide technology was used to control Sagittarius twice. For the first time, 20-30g of 10% pyrazosulfuron-methyl was used every 667m2 5-7 days before rice transplanting, and 3-5kg of fine soil was mixed by soil medicine method, sprayed manually or mechanically (or sprayed with 40l of water), and the water layer in the field was 3-3 layers. The second application, 15 ~ 20 days after rice transplanting, 10% pyrazosulfuron 10 ~ 15 g +30% cypermethrin microemulsion 60ml/667m2; Or apply 10% pyrazosulfuron 10 ~ 15g +so% pretilachlor (excluding safener) EC 60ml； every 667 m2; Or 70g of 10% pyrazosulfuron-10- 15g +50% tribenuron-methyl wettable powder is applied every 667m2, and now it is mixed and used.

2. Treat herbicides with stems and leaves to prevent arrowheads from ploughing in autumn and preparing soil in spring. After soaking in the field, rake it once. May 15, hand transplanting. On July 5, spray with 200 ml of 48% bentazone and 40 liters of water every 667㎡; After 10 days, spraying 200 ml of 48% bentazone solution with 40 liters of water, the control effect on arrowhead was close to 100%, the safety of rice Kenjiandao 6 was good, and the yield increased significantly.