How are herbicides used in rice paddies? A detailed guide to application methods
How are herbicides used in rice paddies? What should you do if herbicide damage occurs? We hope experienced readers can help share their knowledge. Zhongdi Network has compiled the methods for applying herbicides in rice paddies and how to identify and remedy herbicide damage. These are listed below for readers' reference. Methods for using herbicides in rice paddies: The common...
How are herbicides used in rice paddies? What should you do if herbicide damage occurs? We hope experienced readers can help share their knowledgeZhongdi Network has compiled the methods for applying herbicides in rice paddies and how to identify and remedy herbicide damage. These are listed below for readers' reference.
Methods for using herbicides in rice paddies:
The common characteristic of chemical herbicides is that they are highly lethal to weeds when temperatures are high, and less effective when temperatures are low. Therefore, for early rice in the main field, herbicides should be applied about 15 days after transplanting; for middle rice and late rice, it should be done 4 to 6 days after transplanting.
The correct method is: choose a sunny day after the dew has dried, and use 500 to 600 g of 25% nitrofen per mu, or 300 g of 25% nitrofen plus 500 g of sodium pentachlorophenate, or 250 to 300 g of 50% thiobencarb emulsifiable concentrate, mix evenly with 15 kg of moist fine soil, pile and cover for half a day, then spread evenly into the rice paddy.
Do not drain the field within 1 week; keep the water depth at 3 to 6 cm. This method works well against barnyardgrass, nutgrass, and similar weeds, but is ineffective against three-edge grass, duck-tongue grass, wild arrowhead, and other weeds. Therefore, for these weeds, depending on the situation, use 75 to 100 g of 70% MCPA per mu, mix with 40 kg of water, and spray on the second day after the paddy water has been drained; irrigate again 1 day after spraying.
Half a month after transplanting, some rice paddies are prone to growing malignant weeds such as yanzicai (also called bamboo-leaf grass). When it has grown 3 to 5 leaves, use 40 to 50 g of 50% prometryn per mu, add 15 kg of moist fine soil, broadcast, and maintain a water depth of 3 to 6 cm for 7 days; the effect is good. Alternatively, use 40 g of prometryn plus 100 g of 70% MCPA, mix with 15 kg of moist fine soil, and broadcast. This method can not only kill yanzicao but also kill weeds such as Rizhao piaofocao, jiejiecao, duck-tongue grass, wild arrowhead, and wild water chestnut seedlings.
Symptoms of herbicide damage in rice paddies:
The rice seedlings look as if they have been burned; some cannot head normally, and some cannot set grain.
Causes of herbicide damage: the paddy field is too large, resulting in uneven application; using bamboo baskets and similar containers to hold the poisoned soil, which leaks as it is spread; the mixture is too dry, causing the soil and chemical to separate; the paddy field is unevenly tilled or leaks, causing the chemical water to submerge the seedlings or the chemical concentration to increase; entering the field to weed too early, etc.
Remedial measures for herbicide damage in rice paddies:
Method 1: If the seedlings are withered, it is mostly caused by excessive application; immediately drain the chemical water from the field and flush with clean water.
Method 2: For severe herbicide damage, broadcast 50 to 100 kg of quicklime or plant ash per mu; for mild herbicide damage, spray the leaves with 1% bleaching powder solution.
Method 3: If the seedlings still cannot resume growth after the above measures, replant; if replanting is not possible, apply an additional 5 to 7.5 kg of urea per mu.
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