In the process of lettuce cultivation, if the management is not proper, the stalks of the fleshy stems are prone to cracking. The fleshy stems are split longitudinally, reaching the center of the stem, and the splitting part is yellowish brown, perishable, and the quality of the product is degraded, which seriously affects its economic benefits.
First, the cause of the cracked stem
The lettuce stem is a physiological disease, and its main causes are as follows:
1. Variety factors. Different varieties have different resistance to split stems. Generally, purple lettuce leaves are more susceptible to cracking than green leaf lettuce.
2. Uneven supply of fertilizer and water. In the cultivation process, if the supply of fertilizer and water is uneven, the drought will be delayed, especially in the early stage of the expansion of the lettuce stems, and the epidermis of the fleshy stem becomes hardened. After that, if a large amount of water is applied and fertilized, the fleshy stem will rapidly expand, and the growth of the epidermis will not be correspondingly swollen, resulting in cracking.
3. The temperature changes too much. Lettuce enjoys a cool climate, and the growth temperature during the formation of fleshy stems is 18°C-22°C during the day and 12°C-15°C during the night. If the fleshy stems are inflated for a long time at a low temperature, the growth of the fleshy stems is resisted. After that, if the temperature suddenly rises and reaches the temperature required for the normal growth of the lettuce stem, the fleshy stem will grow rapidly and expand, but the epidermis grows slowly, leading to the phenomenon of cracking.
4. The soil is seriously deficient in boron. In the absence of boron, the vitamin C content in lettuce decreased, the plant resistance to stress decreased, and the fleshy stems were prone to cracking.
5. Harvesting too late. The lettuce is too late to harvest, and it is prone to cracking stems.
Second, measures to prevent cracking
1. Choose the right variety. Choose the right variety based on local conditions and climate conditions. For plots with poor irrigation and drainage conditions, in the seasons with large temperature changes, try to choose green leaf lettuce with low water content and strong resistance to cracking stems.
2. Strengthen fertilizer and water management. During the expansion of the fleshy stems, sufficient water and fertilizer supply is required to satisfy the nutrients required for the expansion of the fleshy stems. During this period, the requirements for water and fertilizer management are very strict. Generally, the ground should be watered when it is slightly dry, the watering should be even, and the water should be moderate, so that “small water should be poured, thin fertilizer should be applied, water should be fertilizedâ€, and water should be prevented. Diffuse irrigation, not to wait until the severe drought, then the big water and big fertilizer "sharp", so as not to crack the stem. When fertilizing with water, the fertilizer is first dissolved and then applied to the field with water. During the growth process, lettuce should be fertilized 2-3 times with water. When applying urea, it usually uses 5-8 kg per mu. When applying biogas slurry, it usually uses 300-500 kg per mu. At the same time pay attention to the timely shallow loose soil broken knot.
3. Control the temperature. For the lettuce planted in the greenhouse, the temperature in the shed can be regulated by adjusting the ventilation measures. During the period of the stem formation of the lettuce, the temperature should be promptly ventilated and cooled when the temperature rises to about 24 °C. In the afternoon, when the temperature in the shed drops to about 18 °C, it is necessary to cover the film in time. Try to control the temperature in the shed within the range of 18 ° C - 22 ° C during the day and 12 ° C - 15 ° C during the night.
4. Add boron fertilizer. For the boron-deficient soil, the holding power of boron per acre is 200-250 g, and the lettuce season can be combined with foliar topdressing. For each acre, use 50 g of Su Le Boron or 20 g of polyboron to 30-45 kg of water, spray 1- 2 times, each interval 5-7 days.
5. Harvest at the right time. When the top of the main stem of lettuce is level with the tip of the highest leaf, it is suitable for harvesting. At this time, the fleshy stem has been fully expanded, the quality is crisp and tender, and the stem crack is not easy to occur.
Disclaimer: Some articles on this website are transferred from the Internet. If legal rights of third parties are involved, please inform this website. phone
Pain Relief Patch For Neck Shoulder,Lower Back And Leg
Pain Relief Patch for neck shoulder, lower back and leg.
[Name] Medical Cold Patch
[Package Dimension] 10cm×12cm 2pieces/box
The pain relief patch is composed of three layers, namely, backing lining, middle gel and protective film. It is free from pharmacological, immunological or metabolic ingredients.
[Scope of Application] For cold physiotherapy, closed soft tissue only.
[Indications]
The patches give fast acting pain relief for strains, sprains, cramp, bruises, swollen areas or joint stiffness.
[How To Use a Patch]
Tear off the packaging bag and remove the patch. Remove the protective film and apply the patch on the skin. One piece, one time. The curing effect of each piece can last for 8-12 hours.
[Attention]
Do not apply the patch on the problematic skin, such as wounds, eczema, dermatitis,or in the eyes. People allergic to herbs and the pregnant are advised not to use the medication. If swelling or irritation occurs, please stop using and if any of these effects persist or worsen.notify your doctor or pharmacist promptly. Children using the patch must be supervised by adults.
[Storage Conditions]
Store below 30c in a dry place away from heat and direct sunlight.
Pain Relief Patch,Pain Relief Pad,Pain Relief Plaster,Neck Pain Relief Patch,Back Pain Relief Pacth
Shandong XiJieYiTong International Trade Co.,Ltd. , https://www.xjytmedical.com