How to control subsurface pests in upland rice? A full breakdown of practical techniques

In recent years, with the application and promotion of dry-raised transplanting techniques, upland rice cultivation in Gejiu City has become a new highlight of economic growth in mountainous rural areas. How to do a good job in controlling subsurface pests is an important technical measure for developing upland rice production and ensuring increased yield and income.

The common subsurface pests of upland rice mainly include white grubs (the larvae of scarab beetles), wireworms (the larvae of click beetles), mole crickets, and cutworms (cut worms). These pests live in the soil during their damaging period, feeding on seeds, young sprouts, roots and stems, causing missing plants, gaps in rows, or poor seedling growth, and even destroying the crop, leading to reduced yield.

In response to the current needs of upland rice production, integrated control technical measures for subsurface pests of upland rice are now proposed for producers' reference.

I. Agricultural control

After the previous crop is harvested, plow and sun-dry the soil in time to eliminate overwintering eggs and reduce the source of pests for the coming year; before sowing, harrow and rake the soil to kill some of the pests; before the crop emerges or during the peak outbreak period of 1st-2nd instar cutworm larvae, promptly clear all weeds in the field and bury them deep or carry them out of the field for composting, eliminating hosts and reducing early food for the larvae, thus reducing the occurrence and damage of subsurface pests.

II. Chemical control

(1) Seedbed stage: Take 0.5 kg of 50% phoxim and add an appropriate amount of water, use the gradual expansion method to make 150 kg of poisoned soil, and broadcast it near the roots of the seedlings, broadcasting 20 kg of poisoned soil per mu, which can control a variety of subsurface pests. Use a 2000-fold solution of 2.5% deltamethrin and spray the seedling bed with a watering can in the evening. Because the nighttime temperature is lower, evaporation is less, and with dew coverage, both the soil and the seedlings are in a moist state, which ensures the efficacy of the pesticide and has an especially good effect on controlling cutworms.

(2) Field stage: When transplanting after the rain has soaked the soil, use 100 g of 50% phoxim emulsifiable concentrate per mu, mix with 30 kg of fine sand or fine soil, and broadcast it in the planting furrow, which can control a variety of subsurface pests. When damaged plants are found during the growing period, spray the roots of the plants with an 800-fold solution of 90% crystalline trichlorfon or a 1000-fold solution of 50% phoxim emulsifiable concentrate, focusing on the seedlings near the damaged plants, spraying once every 7-10 days for 2-3 consecutive sprays, which can achieve a relatively good control effect. In plots where cutworms are rampant, spray a 2000-fold solution of 2.5% deltamethrin over the whole field on a clear evening, which can effectively kill cutworm larvae.

III. Trap-killing control.

(1) Plant trapping: By planting sesame and various other crops that cutworms like to lay eggs on, lure them to lay eggs and then pull up the seedlings and burn them.

(2) Poisoned branch trapping: During the adult occurrence period of white grubs, soak fresh poplar or willow branches about 1 m long in a 50-fold dilution of 40% dimethoate, take them out after 10 hours, and insert them into the field before evening, inserting 10-15 branches per mu, which can achieve a very good trap-killing effect.

(3) Light trapping: The adults of scarab beetles, cutworms, and white grubs have a strong tendency toward black light lamps. According to the actual conditions of each place, where possible, set up some black light lamps during the peak adult occurrence period for trap-killing.

(4) Sugar-vinegar-liquor basin trapping: During the peak moth flight period of cutworms, mix brown sugar : vinegar : white liquor : water at 3:3:1:10, then add 50% dichlorvos emulsion at a ratio of 0.1% of the total amount. Put the sugar-vinegar-liquor liquid into an earthen basin, filling it to half a basin, and place it in the field in the evening at a position slightly higher than the crops, placing one basin every 3-5 mu. After removing the trapped moths each day, cover the basin, and uncover it again in the evening to trap moths.

(5) Poison bait trapping: Dilute 50% phoxim emulsifiable concentrate at a pesticide-to-water ratio of 1:20, spray it evenly on chopped fresh grass or vegetable leaves, and place it in small piles in the field in the evening to trap and kill cutworms.