Detailed Explanation of Bletilla Striata Understory Planting Methods and Technical Key Points

I. Woodland Selection

Bletilla striata has the habit of preferring shade and moisture and being intolerant of waterlogging, making it very suitable for understory planting. In areas with an average annual temperature of 15-20°C, annual rainfall above 900 mm, and relative air humidity above 75%, select contiguous understory plots with a slope of ≤25° for planting. Bletilla striata is suitable for planting in fertile, loose, humus-rich, slightly acidic sandy loam or humus loam, and planting in alkaline soil and clay soil should be avoided. The selected planting site should be far from industrial and urban pollution sources.

II. Land Preparation and Bed Making

Clear away dead branches, miscellaneous shrubs, and low side branches in the woodland. In combination with thinning and pruning, adjust the understory light transmittance to 30%-50%. After carefully removing stones and other impurities, evenly spread organic fertilizer or fully decomposed farmyard manure on the ground. Then deep plow more than 30 cm, break the soil into fine particles and rake it level, and make beds along the contour lines. The bed surface width is 120 cm, the height is 15 cm, and the length is unlimited. The bed ditch and surrounding ditch are 40 cm wide and 15 cm deep, and the ditches should be connected to facilitate drainage.

III. Planting Time

Planting can be done in both spring and autumn.

IV. Planting Methods

Choose an overcast day or a time when the sunlight is weak in the afternoon. On the bed surface, use a plant spacing and row spacing of 30 cm x 25 cm, cover with 2/3 cm of loose humus soil, and immediately water thoroughly once with rooting water after planting. Note that farmers who introduce the tissue-cultured domesticated seedlings of Zhongnong 213 Bletilla striata can soak the seedling roots in rooting agent for 2-3 min before planting, and the remaining liquid can be mixed with water and used as rooting water for irrigation.

V. Post-Planting Management

1. Thinning and Replanting

In the year of planting, according to the current growth status of the seedlings, appropriately remove some plants that are too dense, thin and weak, or affected by pests and diseases, and replant in time. After replanting, water thoroughly with rooting water to ensure seedling survival and a reasonable understory planting density of Bletilla striata.

2. Weeding

Bletilla striata seedlings are slender and cannot suppress weeds, so after planting, weed frequently and pull out weeds as soon as they appear. After the plants mature, weeding can be arranged according to the growth of weeds. Chemical herbicides are prohibited.

3. Topdressing

Bletilla striata likes fertilizer. To ensure the quality of the medicinal material, topdressing should mainly use organic fertilizer or fully decomposed farmyard manure, and compound fertilizer may be supplemented in an appropriate amount. In the first year after planting Bletilla striata, no topdressing or only a small amount of topdressing may be applied.

In the second year of planting, topdressing should be carried out before rain in combination with weeding, that is, before the emergence of Bletilla striata in spring. Evenly broadcast organic fertilizer or fully decomposed farmyard manure on the bed surface; in summer during the vigorous growth period of Bletilla striata, apply diluted human and livestock urine water as root topdressing, or broadcast organic fertilizer or fully decomposed farmyard manure mixed with compound fertilizer at a volume ratio of about 1/4.

In autumn, according to specific conditions, plant ash or fully decomposed farmyard manure may be broadcast at the roots. The applied organic fertilizer or fully decomposed farmyard manure should be mixed into the soil with shallow hoeing, and the amount of fertilizer applied should be determined according to the soil fertility of the plot. No topdressing should be applied in the autumn of the harvest year.

4. Water Management

Bletilla striata likes moisture and is not tolerant of drought. During continuous drought weather, pay attention to timely watering, with the amount of watering based on maintaining soil moisture. In rainy seasons, dredge ditches and drain water in time, and avoid water accumulation on the bed surface to prevent root rot.

5. Winter Management

Bletilla striata is not tolerant of severe cold. In high-altitude planting areas with ice and snow freezing in winter, grass should be spread on the bed surface to protect against cold and ensure that Bletilla striata overwinters safely.

VI. Pest and Disease Control

Woodland with no obvious pests and diseases should be selected for planting. During the planting process of Bletilla striata, in early spring and late autumn, promptly remove residual leaves, dead stems, dead grass, and fallen leaves from the planting site, regularly prune overly dense branches and leaves or thin overly dense bamboo clumps to strengthen ventilation; keep woodland drainage unobstructed. During the growing season of Bletilla striata, arrange manual weeding and shrub cutting as needed.

After pests and diseases occur, biological treatment and physical treatment measures should be given priority. When pesticides must be applied, the minimum dosage and high-efficiency, low-toxicity, low-residue pesticides with a short residual period should be selected. Pesticides banned by the state are prohibited. Pesticides are prohibited from use 60 days before harvest.

1. Root Rot

In the early stage of the disease, apply 1% ferrous sulfate solution or quicklime into the diseased holes for disinfection, or spray a 0.2% concentration solution of 50% carbendazim wettable powder, once every 7 days, for 2-3 consecutive times. After the disease occurs, promptly pull out the diseased plants and irrigate the diseased area with a 0.2% concentration solution of copper sulfate.

2. Stem Rot

In the early stage of the disease, pull out the diseased plants and spray a 0.125%-0.167% concentration solution of 75% chlorothalonil wettable powder or a 0.1%-0.125% concentration solution of 50% thiram, at an interval of 7-10 days, for 3-4 consecutive sprays.

3. Leaf Spot

Before the disease occurs and in the early stage of the disease, spray 1:1:100 Bordeaux mixture, or a 0.1% concentration solution of 50% thiram, or a 0.167%-0.2% concentration solution of 65% zineb wettable powder. Spray once every 7-10 days, for 3-4 consecutive sprays.

4. Leaf Blight

In the early stage of the disease, spray Bordeaux mixture at a concentration of 0.5%, or a 0.125%-0.2% concentration solution of 50% thiophanate-methyl, or a 0.1% concentration solution of 50% carbendazim wettable powder, at an interval of 10-15 days, for 3 consecutive sprays.

5. Cutworms

During the adult stage, use black light lamps or sugar-wine-vinegar liquid for trapping and killing; during the larval stage, mix 10% diazinon granules and 5% chlorpyrifos granules with dry fine soil, mix evenly, and broadcast into the soil.

6. Scarab Beetles (White Grubs)

During the peak hatching period of larvae, mix 10% diazinon granules and 5% chlorpyrifos granules with dry fine soil, mix evenly, and broadcast into the soil; during the adult stage, use black light lamps or mercury lamps to trap and kill adults; during the egg stage or larval stage, per 667 sq m, mix 1.5-2 kg of special white grub-type Beauveria bassiana with 15-25 kg of fine soil and apply the pesticide at the roots.

VII. Harvesting

From after the aboveground parts wither in autumn to before sprouting in spring, choose a sunny day, first clear away residual stems and dead leaves on the ground, dig up the rhizomes together with soil, shake off the soil, cut off the stems, cut the rhizomes with bud scales as seeds, remove fibrous roots from the remaining parts, wash clean with clear water, put into boiling water and boil for 5-10 min until there is no white core inside, then sun-dry or dry at ≤70°C. Store in a cool, dry, ventilated place, and pay attention to avoiding light and preventing insects.