Answers to frequently asked questions about grape cultivation

1. How many propagation methods are there for grape seedlings?

There are usually two methods of reproduction of grape seedlings: one is asexual reproduction, that is, vegetative reproduction, and the other is sexual reproduction, that is, seed reproduction.

Vegetative propagation is a method of using part of the organs of grape plants, mainly using stems to propagate and cultivate seedlings. Its advantage is that the new plant has little variation, can maintain the variety characteristics of the mother plant, and can propagate many times in a year. The plants propagated by this method have the advantages of early formation, fast growth and early fruiting period, so they are widely used in production. The methods of asexual propagation include hardwood cuttage, green wood cuttage, striping, grafting and tissue culture of stem tip and stem segment, among which hardwood cuttage and grafting are widely used, which is also a more traditional method. Tissue culture is a modern propagation method with large investment and high requirements for facilities and technology.

Sexual reproduction is a method of using seeds to produce new plants. it is the result of sexual hybridization and genetic recombination. The genetic variability of the new plants is large, so it is difficult to maintain the characteristics of the original varieties, and this method is not used to raise seedlings of good varieties. Conventional grape breeding usually uses seed propagation to obtain hybrid seeds through hybridization, and then screen new varieties with good characters from a large number of seedlings. This method is often used for the breeding of new grape varieties, but it is labor-consuming and time-consuming, and the breeding cycle is long, so it is not suitable for general seedling propagation.

2. How to raise grape seedlings by cuttage?

Grape cuttage seedlings are divided into hardwood cuttings and tender wood cuttings. Hardwood cutting is a widely used method at present. It uses the annual branches with the characteristics of this variety cut in winter as cutting material, usually 2-3 buds per cutting branch, and single bud cutting can be used in rare varieties. The relevant preparatory work should be done before hardwood cutting.

(1) selection of seedling site. The nursery land should choose sandy loam or loam with flat terrain, loose soil, close to water source and easy drainage and irrigation, and consider convenient management, leaving production paths and drainage and irrigation ditches and so on. Before freezing in winter, the nursery land should be ploughed about 50 cm deep, and then mixed with calcium superphosphate (50 kg per mu) and organic fertilizer (ring manure, barnyard manure, compost, 3000 kg per mu) and sprinkled on the surface, rough rake, and then fine rake again after freezing next spring. When the soil moisture is poor, you should first pour through the water, and then set up the ridge and set up the bed for backup. In northern areas, ridge planting is mostly used to raise seedlings, which is conducive to cold protection, heat preservation and moisturization. Seedling land should pay attention to crop rotation to avoid continuous cropping, the previous crop had better not use potato and eggplant vegetable garden, in order to avoid the harm of diseases and insect pests.

(2) choose a good insert. Take the cuttings out of the storage ditch and cut them according to the desired length. The length of single bud cuttings is 5 cm 10 cm, the double bud cuttings 10 cm or 3 buds cuttings 10 cm 20 cm, the thickness of cuttings is more than 0.5cm, the length of internodes is uniform, the bud eyes are full, the pith is not more than 1/3 of the diameter of cuttings, the skin color of cuttings is yellow to reddish brown, and there are no diseases and insects. When cutting, cut the stubble at the upper end of the cuttings 1 cm away from the bud, and the lower end of the cut close to 0.5 cm below the node, which can even be cut on the node, because there are many nutrients stored on the node, which is easy to germinate and root. After the cuttings are cut, tie them into a bundle every 50 or 100, waiting for root or cutting.

(3) dipping strips before insertion. Soak the cut cuttings in bundles of water for 12 hours until the cut is bright green until it is saturated with water. In order to improve the survival rate of cuttage seedlings, drug treatment is often used to promote its rooting. Bundles of cuttings at the base of 1 cm to 2 cm are usually dipped with medicine. But do not put medicine on the top of the cuttings. The commonly used agents are: indole acetic acid 40~50mg/kg, sodium naphthalene acetate 100mg/kg, soaking for 12 hours for 24 hours; indole butyric acid 100mg/kg soaking for 12 hours, or 200~300mg/kg rapid dipping, the base of the cuttings is soaked in the medicine solution immediately; it can also be quickly dipped with naphthylacetic acid 300~450mg/kg. The results showed that soaking the branches with 0.2% potassium dihydrogen phosphate for 48 hours could also improve the survival rate of cuttage seedlings.

(4) cutting time. It is suitable to raise seedlings by cutting in the open air when the soil temperature is above 8: 10 ℃ in early spring.

(5) cutting method. Ridge or border planting can be used.

① ridge planting. The seedling land was deeply ploughed and leveled with fine rake and ridged. Ridging from east to west, with a row spacing of about 50 cm, first dig a ditch of 15 cm in depth and 20 cm in width, turn the ditch soil northward to form a soil ridge 20 cm high, and then insert the treated cuttings along the ditch wall at a plant spacing of 10 cm to 15 cm. When the cuttings are long, the cuttings can be tilted and inserted, and then cover the soil from the south of the ditch, and then cover the soil with feet and water, so that the fine soil is more than 3 cm and 5 cm. If covered with plastic film or build a small arch shed, it is more conducive to cuttings to take root early.

② border insertion method. After leveling the seedling land, the deep ploughing fine rake was leveled into a border with a width of 1 cm and 1.5 m in the north-south direction. The border was generally 20 cm in length. The ditch was dug according to the row spacing of 25 cm and 30 cm, and the ditch was about 10 cm deep. The cuttings were inserted into the trench, the plant spacing was 10 cm, the terminal bud was flat with the ground, the bud eyes were upward and sunrise, and the cuttings were covered with fine soil 3 cm and 5 cm, and then watered once. Ploughing in time after the water seeps down, and when possible, it can be covered with plastic film after ploughing to preserve soil moisture and raise temperature, and promote cuttings to take root.

Ridge planting soil temperature rises quickly, sprouts early, ploughing and weeding is convenient, ventilated and transparent, and seedling growth is better than border planting.

3. How to raise seedlings in nutrition bag?

In the protective facilities, the cuttings are cut in the nutrition bag in advance to make the cuttings take root and sprout ahead of time, and then planted in the field when the temperature is high after the frost in the open field. Nutrition bag seedling has the advantages of short seedling period, high survival rate and good seedling growth, which can obviously improve the seedling efficiency.

The plastic bags used for raising seedlings in this method can be made of ordinary agricultural film. The plastic bag is about 10 centimeters in diameter and 18-20 centimeters high. there are several small holes in the bottom or bottom of the bag to facilitate air permeability and water seepage. The nutrient soil used for raising seedlings can be prepared with fertile loam, manure and aeration medium (such as peat soil, fine slag, river sand, etc.).

When raising seedlings, put the nutritious soil and the treated cuttings into the bag. The nutritive soil should be compacted, leaving a space of 1cm to 2cm on the mouth of the bag for watering. The packed nutrition bags will be closely arranged in the pre-prepared seedling bed, which is 20cm to 30cm deep and unlimited in width and length. The whole bed is filled with nutrition bags and watered immediately. In order to keep moisture and heat preservation, a small plastic arch shed can be buckled on the seedling bed (can also be raised in a plastic greenhouse). Generally, the temperature is kept at about 20 ℃, and the humidity is 80%, not less than 60%. When the cuttings grow 3-4 leaves, the arch shed can be removed, and when 5-6 leaves grow on the new shoot of the seedlings, they can be transplanted.