Barnyardgrass in Rice Fields Is Hard to Control - Only Because You Haven't Used These Measures

Five or six years ago, using 10% cyhalofop-butyl emulsifiable concentrate gave excellent control of barnyardgrass. Now, after using up almost all the herbicides for rice fields, there is still no effect. Why? When you ask at the agricultural supply store, the most common answer is "This is 'green barnyardgrass'. Try adding a bit more. If it doesn't die, it's not because my pesticide is bad."

My friend, I believe you have also tried penoxsulam, oxyfluorfen, mefenacet, propanil and many other herbicides again and again, increasing the dose again and again, yet the barnyardgrass still sways in the field with the wind. Just hearing about it makes Science Xingnong feel frustrated. Below I will give you suggestions from two aspects: why barnyardgrass has become so resistant to herbicides in recent years, and how to use chemicals to control barnyardgrass. I hope it will be helpful.

First, the journey of green barnyardgrass's resistance to herbicides.

Since resistance to the herbicide quinclorac was discovered in Ruian in 2003, in recent years large numbers of cases of severe resistance to barnyardgrass-killing chemicals have been found in various places. It has developed to the point that resistant barnyardgrass in rice fields can no longer be controlled by any chemical, and can only be pulled out by hand.

There are two reasons for this. 1. There are many varieties of barnyardgrass. They are mixed in with rice seeds, or travel all over the country on harvesters. Crossbreeding among barnyardgrass varieties and invasion by barnyardgrass varieties from other places both cause more and more resistant barnyardgrass. 2. The abuse of chemical herbicides. As barnyardgrass resistance increases, people keep increasing the dose of herbicides. Barnyardgrass that originally would have taken nearly a hundred years to develop a high level of resistance has, in just a few short years, developed to the point of being beyond saving. Because of the above two reasons, the journey of green barnyardgrass's resistance to herbicides has been smooth sailing, reaching an unprecedented "height."

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Second, how to use chemicals to control green barnyardgrass.

Take "closed weed control as the main approach, killing barnyardgrass seedlings as a supplement, plus pulling out the barnyardgrass that slips through the net" as the guideline. For closed weed control, about 3 days after rice sowing, you can choose butachlor or pretilachlor for spray treatment, and be careful to keep the soil moist.

Barnyardgrass should be killed early, before it reaches the 3-leaf-1-heart stage. At this time the amount of chemical used is small and it is safe for rice. Once it is bigger, it becomes hard to kill. Chemicals can be mixed for use. Depending on the location, you can consult the local pesticide dealer. Pay attention to coordinating with drainage, then return water after 24 hours. Keeping it for 7 days gives the best effect.

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Pulling out the barnyardgrass that slips through the net requires timely pulling before the barnyardgrass heads out, to reduce barnyardgrass seeds left in the field and avoid the situation of it becoming harder to kill year after year. If I really told you there is a chemical that can completely eradicate it, that would obviously be a lie. I believe that after understanding why barnyardgrass is so hard to control and the main methods for controlling barnyardgrass, you will also be somewhat understanding. If you think Science Xingnong speaks scientifically and is straightforward, give it a like~