Cultivation Techniques and Management Methods for Cut Stock
Stock, Matthiola incana R.Br., also known as hoary stock and stock, belongs to the genus Matthiola in the family Brassicaceae (Cruciferae), and is a perennial or annual/biennial plant. Stock is native to the Mediterranean coast, was already known in ancient Greece, and by 1542 there were already three flower colors: red, purple, and white. In 1568, the first record of double-flowered cultivars appeared. Cultivars bred before 1900 reached a double-flower rate of over 50%. After the 20th century, extremely effective cultivar improvement work was carried out. Some cut flower cultivars have flower stems reaching 80 cm, with a double-flower rate of 95%. It is now widely cultivated in gardens across our country. Stock has a relatively long flowering period, abundant flowers, large inflorescences, rich colors, and fragrance. It can be used as material for flower beds and flower borders and for potted plants to beautify rooms, and is also an excellent cut flower plant.
Ecological Habits of Stock
Stock prefers a climate environment that is warm and humid in winter and cool and dry in summer. During the seedling stage it tolerates slight shade, and during flower bud formation and the flowering period it prefers sufficient sunlight. It is relatively cold-tolerant and can withstand short-term low temperatures of around 0°C, but is not tolerant of frost. It avoids hot and humid summer weather, and diseases easily occur during plum rain weather. Generally, cultivation is mainly by planting in winter and flowering in spring. Because the whole plant has soft hairs, water evaporation from the body is relatively low, so during the growing period it generally needs less watering, and during the flowering period it needs an appropriate amount of watering. The root system is extremely developed, and it requires fertile, loose soil with a deep soil layer. It is difficult to grow in heavy clay soil and poorly drained land.
Types and Cultivars
There are very many horticultural cultivars, with two strain types: single-flowered and double-flowered. The double-flowered strain has high ornamental value; the single-flowered strain can set seed, while the double-flowered strain cannot. Generally, plants grown from sowing flat seeds can usually produce large numbers of double flowers; while plump, full seeds mostly produce plants with single flowers. Flower colors include pink, deep red, light purple, deep purple, pure white, pale yellow, bright yellow, blue-purple, etc. In production, cultivars such as white-flowered, pink-flowered, and purple-flowered ones are generally used to produce cut flowers.
The main cultivated cultivars include the white 'Aida', the pale yellow 'Carmen', the red 'Francesca', the purple 'Arabella', and the pale purplish-red 'Incana', etc. According to plant height, there are three types: tall, medium, and dwarf; according to different flowering periods, there are cultivars such as summer stock, autumn stock, and winter stock; according to different cultivation habits, there are annual and biennial types.
Propagation Methods
Seed sowing is the main method of propagation, and cuttings can also be used. Usually, biennial cultivars are mostly cultivated. In Yunnan Province, sowing is done in November. After sowing, under conditions of 15°C-22°C, germination occurs in 7-10 days, and after about another 30-40 days, when there are 6-7 true leaves, they are planted out. They can bloom in March. When sowing, the potting soil should be watered thoroughly. After sowing, do not water directly. If the soil becomes dry and turns white, spray with a watering can or use the "pot soaking method" to keep the soil moist. Place the seedling tray in a shaded area and cover it with shading material. After seedlings emerge, gradually remove the shading material to let them receive light.
Note that autumn sowing should not be too late, otherwise it will affect plant growth, overwintering, and the quantity and quality of flowering.
Cultivation and Management Techniques
Choose sandy loam rich in humus as the cultivation substrate. Cut flowers are mostly cultivated in greenhouses, and the planting site should avoid waterlogging. When seedlings are 8-10 cm tall, they can be planted out. The planting density is 30-40 plants per sq m, planted in holes at equal spacing. Stock is a taproot plant and is not tolerant of transplanting. Therefore, to ensure survival, when transplanting, carry more original soil and try not to damage the root system. After planting out, water thoroughly. In the early growth stage, water should be controlled to promote root development, keeping the soil in a slightly moist and somewhat dry state, generally watering once every 3-4 days. The lower the temperature, the less watering. After the environmental temperature rises, increase the amount of watering, otherwise the plants will grow shorter, which will affect the quality of cut flowers. When planting, apply sufficient base fertilizer, and in the early growth stage apply appropriate fertilizer according to plant growth. Do not apply too much fertilizer at one time; apply thin fertilizer frequently, otherwise it is easy to cause excessive vegetative growth. After the plants form flower buds, apply a 0.1%-0.2% potassium dihydrogen phosphate solution as a top dressing, once a week. [Page break]
Stock prefers light and requires full sun. Temperature is regulated through plastic greenhouses, controlled between 10°C-30°C, and during overwintering the temperature should not be lower than 5°C. In Yunnan, in winter, the temperature is raised for protection by sealing with plastic film; in summer, the plastic film is opened, and ventilation is used to lower the environmental temperature. This is beneficial for cut flower production, and has low cost, relatively high yield, and superior quality.
During plant growth, as the inflorescence grows, the plant weight increases, and the plants easily lodge, affecting cut flower quality and making fertilization and watering difficult, while also affecting ventilation and making disease infection easy. Therefore, netting should be set up at the flower bud stage. In addition, during the suitable period, pay attention to intertillage and weeding, so as to favor the reproduction and activity of beneficial microorganisms in the soil, thereby promoting the decomposition of organic matter in the soil and creating good conditions for flower root growth and nutrient absorption. In summer, with high temperature and high humidity, pay attention to the prevention and control of pests and diseases.
Pest and Disease Control
The main pests and diseases of stock include:
(1) Leaf spot: caused by continuous cropping, dense planting, poor ventilation, excessive humidity, and other reasons.
Control methods: ① Remove diseased plant residues to reduce sources of infection; ② Select disease-resistant cultivars, appropriately increase the application of phosphorus and potassium fertilizers, and improve plant disease resistance; ③ Implement crop rotation; ④ Irrigate along the soil surface and avoid spraying water on the plants; ⑤ Spray 1% Bordeaux mixture or 25% carbendazim wettable powder at 300-600 times dilution, or 50% thiophanate-methyl at 1000 times dilution, or 80% mancozeb at 400-600 times dilution.
(2) Damping-off: mainly spread through soil and fertilizer, and is likely to occur under conditions of excessive humidity, excessively high soil temperature, overly dense sowing, and weak seedling growth.
Control methods: ① Promptly pull out diseased plants; ② Disinfect the soil; ③ In the early stage before seedlings emerge, appropriately control watering; ④ In the early stage of disease occurrence, drench with 50% amobam aqueous solution at 300-400 times dilution or 70% thiophanate-methyl wettable powder at 1000 times dilution.
(3) Rot: mainly caused by high humidity, insufficient light, and poor ventilation.
Control methods: Appropriately control moisture, and provide light and ventilation.
(4) Root-knot nematode disease: mainly spread through irrigation and agricultural operations. Diseased soil and residual plants are the main sources of infection.
Control methods: ① Disinfect the soil; ② Carry out chemical treatment.
(5) Insect pests: mainly aphids, which gather on leaves, tender buds, and flower buds, piercing into plant tissues with piercing-sucking mouthparts to suck sap, causing yellow spots or black spots at the damaged parts. Damaged leaves shrivel and fall off, and flower buds shrink or grow abnormally. In severe cases, the plants may die. Aphids can secrete honeydew, leading to bacterial growth and inducing diseases such as sooty mold.
Control methods: ① Eliminate them by clearing nearby weeds; ② Spray 40% dimethoate or omethoate at 1000-1500 times dilution, or fenvalerate at 2000-3000 times dilution, or 80% dichlorvos at 1000 times dilution, etc.
Harvesting and Storage of Cut Flowers
Harvest when 1/2-2/3 of the florets on the flower stem have opened. The best harvesting time is in the morning or evening. At this time, the cells in the plant contain more water, which can extend the freshness retention time of the fresh flowers. Cut from the base of the stem to make the flower stem longer. Make bundles of 10-20 stems each. After tying, place the base in a container to absorb water fully, then wrap with wrapping paper or plastic film, and refrigerate or box for market. Cut flower stems can be kept at 4°C for 3-4 days, and after 3-4 days they should be returned to a room-temperature environment.