What formula should be used for weed control in direct-seeded upland rice? Practical solutions shared
Upland rice refers to the selection of high-quality rice varieties with strong drought tolerance under dry field conditions, using dry direct seeding. The entire growth period relies mainly on natural rainfall. In addition, weed control throughout the process is also key. Below, the editor will share with you the weed control formula for direct-seeded upland rice.
I. Weed control formula for direct-seeded upland rice
Soil sealing: per mu, mix 250ml of 60% butachlor + 400ml of 48% butralin + 50g of 50% bensulfuron-methyl + 50g of MCPA-sodium + 100ml of 33% pendimethalin with 75kg of water, and spray the soil 7-10 days after sowing; stem and leaf treatment: per mu, mix 250ml of 60% butachlor + 25g of 50% bensulfuron-methyl + 50ml of Kuokodan with 40kg of water, and spray when barnyardgrass is at the 2-leaf stage.
II. Cultivation techniques for direct-seeded upland rice
1. Varieties
For production, varieties that have passed national or provincial approval and are operated through an integrated breeding, propagation, and promotion system should be selected. For example: nationally approved varieties include Zhonghan 297, Lvhan No. 1, etc., and Anhui Province-approved varieties include Han- dao 906, Xinliangyou 212, etc.
2. Direct seeding
Upland rice is also called drought-resistant water-saving rice. Unlike “paddy rice” grown in flooded fields, upland rice does not need a water layer throughout its life. It is usually direct-seeded in dry land or dry fields and then relies on rainfall, or on this basis receives a moderate amount of supplemental irrigation. However, upland rice is not wheat or corn; during special critical periods, irrigation conditions must be available, otherwise yield will be greatly affected. Although upland rice has similar requirements for light and temperature as rice, its water requirement throughout its life is about 2/3 of rice, or 1/2 or less.
3. Soil
In Anhui Province, upland rice is most suitable for planting in low-lying, flood-prone dry land and water-deficient rice fields. It is also suitable for mountainous areas with more rainfall, and for hilly land and dry land that can be irrigated.
4. Sowing
From mid-May to mid-June, sun-dry the rice seeds for 1-2 days before sowing. Mechanical drilling or manual hole sowing is suitable, with 3-5 kg of rice seed per mu (use the lower seed rate for sandy soil and the higher seed rate for clay soil), and sowing depth of 2-4 cm. At this time, if the weather forecast shows no effective precipitation, irrigate the first thorough watering in time to strive for early seedlings, uniform seedlings, and full stands. At the 3-4 leaf stage of the seedlings, conduct field inspection. If there are missing seedlings or broken rows, transplant from dense areas to fill gaps.
4. Fertilization
Base fertilizer: apply sufficient base fertilizer before plowing, 20-30 kg of ternary compound fertilizer; seed fertilizer: before sowing, apply 15 kg of ternary compound fertilizer and 10 kg of urea in holes or furrows; topdressing: at the 3-4 leaf stage of the seedlings, apply 8 to 10 kg of urea and 5 to 10 kg of potassium fertilizer per mu; about 60 days after sowing, apply 10 kg of urea per mu, and spray 70 to 100 ml of plant nutrient solution at the grain-filling stage.
5. Watering
If the weather is favorable, upland rice may not need watering throughout the entire growth period. However, if there is no effective precipitation for a long time and the farmland is dry, the “three waterings” are indispensable no matter what, namely the seedling establishment water after sowing, the booting water, and the heading and grain-filling water.
6. Pest and disease control
(1) Control of mole crickets: together with base fertilizer, use 30 kg of phoxim granules per hectare to prevent mole crickets from eating seeds, tunneling through soil and letting air in, and causing dead seedlings.
(2) Control of rice blast: at the early stage of rice blast occurrence and 2-3 days at the heading stage, Fuji One can be used for control.
The control of weeds in upland rice fields is mainly the control of barnyardgrass and other weeds, and should follow the principle of “scientific pesticide use, early prevention and early treatment.”