High-yield cultivation techniques for bulb propagation of Asiatic lilies in semi-arid regions
1. Site selection, land preparation and fertilization. According to the growth characteristics of Asiatic lilies, choose level, fertile sandy loam with deep soil layers, high organic matter content, loose texture, and good drainage and irrigation for cultivation. After selection, plow deeply to 30 cm, harrow fine and level. In combination with deep plowing, apply 6 cubic meters of fully decomposed high-quality farm manure per 667 sq m. For each cubic meter of manure, use 50% carbendazim and 50% phoxim at 1000 g each, add 50 kg of water, stir evenly and pile up to ferment. Then make beds running north-south, 1-2 m wide and 10-15 m long, with bed ridges 25-30 cm wide. Water thoroughly once before planting. When the soil holds together when squeezed in the hand and breaks apart when dropped, it is ready for planting.
2. Planting. Generally, planting time is around mid-April, no later than May 1. Before planting, soak the chemically treated small bulbs in an 800-fold carbendazim aqueous solution for 30 minutes, then plant. Generally, use a hoe to open furrows 12 cm deep, with 20 cm row spacing and 8 cm plant spacing. Place the small bulbs with the roots facing down, plant them evenly in the furrows, scatter poisoned grain, apply 25 kg of diammonium phosphate and 10 kg of potassium sulfate as seed fertilizer per 667 sq m, and cover with 8-10 cm of soil. After planting each bed, water lightly. At the same time, plant corn on the bed ridges at 1.0 m spacing to provide shade for the lilies later.
3. Field management
3.1 Water and fertilizer management. Do not water before emergence unless drought occurs; focus on raising soil temperature, but keep the soil moist. After 15-20 days, the seedlings begin to emerge. When the seedlings are fully emerged and all leaves have unfolded, apply the first topdressing together with irrigation, flushing 10 kg of dissolved urea per 667 sq m with the water. After 20 days, apply the second topdressing together with irrigation, flushing 10 kg of dissolved urea and 2.5 kg of ferrous sulfate per 667 sq m with the water. At bud stage, apply the third topdressing together with irrigation, flushing a solution of 10 kg of diammonium phosphate and 10 kg of potassium sulfate with the water. In the middle and late stages, pay attention to foliar fertilization. Generally starting from mid-July, according to growth conditions, spray the leaves 2-3 times. The main fertilizers are monopotassium phosphate, borax and multi-element micro-fertilizers. Throughout the growing period, irrigate promptly during drought, and pay attention to drainage during the rainy season, but do not water for 10 days before harvesting the bulbs.
3.2 Timely intertillage and weeding. Because lily plants grow slowly, pay attention throughout the growing period to preventing weed overgrowth. Remove weeds promptly by hand. After emergence, use a small iron hoe 5 cm wide for shallow intertillage to a depth of 2-3 cm. Especially after each watering, when the soil surface dries, carry out intertillage promptly. The principle of intertillage is shallow rather than deep, to prevent damage to the bulbs.
3.3 Remove flower buds and diseased plants. Due to the high level of fertilizer and water management and the large size of some bulbs, flower buds tend to appear during growth. After buds appear, remove them promptly to prevent nutrient consumption and promote the growth and enlargement of the bulbs. At the same time, throughout the growing period, if diseased plants are found, when few in number, dig them out promptly with the roots, take them out of the field and bury them deeply or burn them in a centralized manner. In addition, in the later stage, remove the leaves below the ear from the corn on the ridges. This increases light penetration and ventilation, and reduces the occurrence of lily diseases. The management techniques for corn throughout the growing period are the same as for field corn.
3.4 Pest and disease control. The main diseases of lilies are Phytophthora blight, gray mold and viral disease; the main lily pests are aphids, leafminers and various underground pests. Phytophthora blight mainly damages the root and stem base, and also damages stems, leaves, flowers and bulbs. Water-soaked spots appear on the affected parts, then turn brown and shrink, the plant wilts, and the stem breaks at the affected part and dies. In the early stage of disease, spray 40% phosethyl-Al 300-fold solution or 25% metalaxyl 500-fold solution. Gray mold is a common disease in cultivation, damaging leaves, buds, stems and flowers. In the early stage of disease, spray 50% thiram wettable powder 600-fold solution or 70% thiophanate-methyl wettable powder 800-fold solution. Viral disease mainly appears as shortened plants, deformities, chlorotic spots on leaves or white-green alternating bands and necrosis, twisted leaves, clustered plants and flower color variation. In the early stage of disease, spray virus-extract wettable powder 500-fold solution, and also spray Jinerkang 200-fold solution or 20% ningnanmycin 200-260-fold solution for control, while thoroughly eliminating aphids. Underground pests can be controlled with poisoned grain or poisoned soil. Leafminers can be controlled by spraying 70% qianke at 10 g per 667 sq m, mixed with 50 kg of water. Aphids can be controlled by spraying 10% bidan 1500-fold solution.
4. Harvesting and storage of bulbs. Bulbs should be harvested before the soil freezes, in our region around late September to early October, when the aboveground parts wither. The method is to dig out the bulbs with a four-tooth iron fork. Be very careful not to damage the bulbs and root system, and do not immediately separate the mother bulbs from the daughter bulbs. Place them in a cool place to dry for 1-2 days (never place them in direct sunlight), then remove soil and separate the daughter bulbs. If soil cannot be removed, rinse clean with water at 5-10°C, dry in the shade after washing, then grade the bulbs by size, put them separately into plastic bags with peat soil added (the plastic bags have small holes), and then pack them into boxes. The peat soil should be disinfected with 800-fold 50% carbendazim solution. Place the packed boxes in a well-ventilated room at 5°C, maintain for 4 weeks, and if the temperature is maintained for a long time, they can remain dormant for about 7 months. If the temperature is well controlled, the bulbs can be stored for more than one year.