Detailed Explanation of Key Technical Points for Summer Sowing of Achyranthes bidentata After Wheat Harvest

I. Site Selection and Pre-Sowing Preparation

For plots to be planted with Achyranthes bidentata after wheat harvest, sandy loam soil with deep soil layers, sunny exposure, high and dry position, and loose fertile texture must be selected. Saline-alkali land, heavy clay land, waterlogged lowland and plots with thin soil layers cannot be used for planting. After wheat is harvested with a combine harvester, gather the longer (over 10 cm) and piled wheat straw together with a rake and set aside for later use. Then broadcast per mu 3000 kg of decomposed farmyard manure, 30 kg of diammonium phosphate or 50 kg of compound fertilizer, rotary till the soil to mix the fertilizer evenly with the soil, and press (the surface soil must not be too loose); according to the terrain, dig a drainage ditch every 1—2 m.

II. Seed Treatment

Before sowing, first winnow the seeds, select plump seeds, and sun-dry them for 2 days. The day before sowing, put the plump sun-dried seeds into warm water at about 20 degrees and soak for 12 hours, remove and air-dry the moisture, then they can be sown.

III. Sowing Techniques

After wheat or rapeseed harvest, if it is a drill-sown wheat plot, shallow furrows about 1—2 cm deep can be opened row by row in the wheat stubble ridges with wheat residue after harvest, mix Achyranthes bidentata seeds with fine sandy soil and evenly sprinkle into the furrows, cover with soil just until the seeds are no longer visible, not too thick, and press. If it is a broadcast-sown wheat plot, after plowing the soil, open furrows at a row spacing of 20—25 cm and sow. For large-area planting, a professional seeder can be used, adjust the seeder so that the sowing depth is 1—2 cm, row spacing 20 cm, and seed plant spacing about 2 cm; the procedures of furrowing, sowing, covering with soil and pressing are completed in one pass, which can greatly improve efficiency. According to the planting experience of the Heze Run Kang Chinese Medicinal Materials Research Institute in Shandong in recent years, because the density of summer-sown Achyranthes bidentata after wheat stubble is slightly higher, the suitable seeding rate per mu is 2—3 kg. After sowing is completed, evenly scatter the reserved wheat straw thinly over the ground surface, which can reduce sunlight exposure, maintain surface soil moisture, and at the same time mitigate the adverse effects of heavy rain after sowing and before emergence, conducive to uniform emergence.

IV. Field Management

1. Intertillage and soil loosening: Under the condition of maintaining soil moisture and preventing surface soil from crusting, seedlings can emerge 5—7 days after sowing. When seedlings are 2—3 cm tall, carry out intertillage and soil loosening, and at the same time thin out overly dense seedlings (clumped seedlings) and weed.

2. Thinning and final singling: When seedlings are about 4—5 cm tall, thin according to a plant spacing of 4 cm; when seedlings are 6—8 cm tall, final singling is done, maintaining a plant spacing of about 8 cm; at the same time pull out weeds in the field.

3. Cutting lateral roots: 5—7 days after final singling, when seedlings are 12—15 cm tall, in combination with intertillage and weeding, hoe off the lateral roots in the surface soil to facilitate downward elongation of the main root and improve yield and quality.

4. Water management: After sowing until emergence, the surface soil should be kept moist; if drought occurs, spray water in time; during the seedling stage, keep the surface soil dry and loose and the lower soil moist, to facilitate downward root growth; from mid-to-late August to mid-to-late September, the main root basically stops growing downward, so irrigation should be appropriately increased to facilitate thickening of the main root; from late September to harvest, control moisture, no watering is needed, and pay attention to drainage.

5. Topping to promote root growth: Entering August, plants that grow too vigorously should be topped in time, leaving plants 35—40 cm tall, cutting off the top with a sickle, to promote thickening of the main root; thereafter top continuously 2—3 times.

6. Disease and pest control

(1) White rust: In the early stage of the disease, white nearly round to irregular blister spots, that is, spore piles, appear on the back of Achyranthes bidentata leaves, which can cause the leaves to yellow and wither, and finally die. Control method: In the early stage of the disease, use 50% thiophanate-methyl wettable powder 1000 times solution, spray once every 10 days, continuously spray 2—3 times.

(2) Leaf spot: In the early stage of leaf infection, many water-soaked dark green round to polygonal small spots appear on the leaf surface, gradually expanding to form brown to dark brown polygonal spots between the veins; in the early stage of petiole infection, black short streak spots appear, slightly sunken, and the petiole dries up and curls. Control methods: Remove diseased leaves to reduce the source of pathogens; adopt high-ridge cultivation, strictly prohibit flood irrigation, and reduce infection through water flow. For chemical control, spray with 50% thiophanate-methyl wettable powder 1000 times solution or ferrous sulfate 500 times solution, once about every 10 days, continuously control 2—3 times.

(3) Silver-striped noctuid: It is an omnivorous pest. If not controlled in time, tender shoots, tender leaves and flower buds are often eaten, causing leaves to curl and wither. Control methods: According to the damage symptoms or insect droppings, use early morning, evening or cloudy days for manual capture; larvae are generally located on the leaf surface or at the tips of tender shoots, are easy to find, and are not active; this method is very effective when labor is sufficient. For chemical control, during the larval stage, spray 90% trichlorfon 800-1000 times solution or 50% phoxim 1000 times spray, spray once every 5 days, and spray 3 times to cure.

V. Harvesting and Processing

For Achyranthes bidentata sown in summer after wheat stubble, in late autumn of the same year in November before the soil freezes, when the aboveground part becomes withered and yellow, it can be harvested. Before harvesting, first use a sickle to cut off the withered stems aboveground, as close to the ground as possible, then use a rake to rake the withered stems and leaves aboveground to one side, and begin harvesting; when digging, be careful to avoid breaking them as much as possible. If the planting area is relatively large, an iron plow can be used to plow and harvest row by row, turning out each row with an iron fork, carefully picking out the root segments, and striving to keep the root strips intact; in recent years, harvesters specially for harvesting rhizomes have been produced, and those with the means can purchase or rent a harvester to harvest. For the harvested Achyranthes bidentata root strips, cut off the reed head, remove soil and impurities, sun-dry or oven-dry; when sun-drying, prevent freezing or being soaked by rain and snow, so as not to turn purple and black and affect root quality; after drying, bundle the root strips into small bundles and they can be sold.