Recommended herbicides for rice-crayfish co-culture paddies

In recent years, rice-field crayfish farming has been a fairly popular aquaculture project. It uses the natural environment of the paddy field, supplemented by an artificially created ecosystem, to both grow rice and farm red swamp crayfish. So, what herbicides are suitable for rice-crayfish co-culture paddies?

1. What herbicides are suitable for rice-crayfish co-culture paddies?

Crayfish-rice paddies need low-toxicity herbicides that have no effect on crayfish. You can use 60% butachlor 80-100 ml diluted in 40 jin of water for spraying, while adding the herbicide safener Anfa Ge; keep the water layer at 2-3 cm, and after 24 hours of application, irrigate with fresh water.

2. Rice-field crayfish farming techniques

1. Building the crayfish field

Choose a field with good water quality, sufficient water, no pollution sources nearby, strong water retention capacity, convenient drainage and irrigation, and no risk of flooding by floods for rice-field crayfish farming. The area can be as small as a few mu, or as large as dozens of mu or over a hundred mu. Build an escape-prevention wall around the field with plastic film, cement boards, asbestos tiles or calcium-plastic boards to prevent the red swamp crayfish from escaping.

2. Stocking crayfish fry

Before stocking, test the water; only after the water test is safe can the crayfish be stocked. There are two times for stocking red swamp crayfish: first, in early September after the rice harvest, stock brood crayfish directly into the paddy field to let them reproduce on their own; according to the actual situation of rice-field farming, generally stock 20 kg of red swamp crayfish per mu, with a female-to-male ratio of 3:1. Second, in May after rice seedlings are transplanted, stock juvenile crayfish of 2-4 cm at 1500-2000 individuals/mu or 30 kg/mu.

3. Daily management

Persist in patrolling the field every morning and evening, observing changes in the water color in the ditches and the crayfish's activity, feeding and growth. Field management mainly focuses on rice field drying, pesticide use, and escape and pest prevention. For rice field drying, light drying is advisable; do not drain the field water completely. Lower the water level only until the field surface is exposed, and keep the time short. If abnormalities are found in the red swamp crayfish, immediately add water.

4. Feeding management

For rice-field farming of red swamp crayfish, the base fertilizer must be sufficient, mainly applying decomposed organic fertilizer, applied all at once into the tilled layer before transplanting rice seedlings, to achieve the goal of lasting and long-term fertility. Topdressing is generally done once a month: urea 5 kg/mu, compound fertilizer 10 kg/mu. Rice-field crayfish farming generally does not require feeding; during the peak growth period of red swamp crayfish, you can appropriately feed some animal-based feed, such as crushed snails, mussels, and slaughterhouse scraps.

5. Harvesting

Harvest red swamp crayfish that have reached commercial specifications for sale on the market, and keep those that have not reached specifications in the paddy field for continued farming, reducing the density of red swamp crayfish in the paddy field and promoting the rapid growth of small-sized crayfish. From mid-May to mid-July, using shrimp cages and ground cage nets for capture gives better results. You can also use a dip net to scoop back and forth in the crayfish ditch, and finally drain the field water before harvesting the rice to capture all the crayfish. When juvenile crayfish are stocked in February-March, the harvest peak generally occurs in September-October. When brood crayfish are stocked in September-October, the harvest peak generally occurs in May-June of the following year. Usually, capture the large ones and leave the small ones; fishing is prohibited during the breeding period.

Red swamp crayfish are very sensitive to many pesticides. The principle of rice-field crayfish farming is to resolutely avoid pesticide use when possible, and when pesticide use is needed, choose high-efficiency, low-toxicity pesticides and biological agents. When applying pesticides, strictly control the safe use concentration of the pesticide to ensure the safety of the crayfish, and spray the pesticide on the rice leaves, trying not to spray it into the water, and preferably apply the pesticide by zones.