Cultivation techniques of guava

Guava is a highly adaptable tropical fruit tree, native to tropical America, spread to the tropical and subtropical regions of the world in the 16th-17th century, and was introduced into China at the end of the 17th century. Now it is cultivated in Taiwan, Hainan, Guangdong, Guangxi, Fujian, Jiangxi, Yunnan and other provinces in China, and some places have become wild fruit trees with high cultivation value. Let's take a look at the planting techniques of guava.

Growth habits of guava

Guava is born in wasteland or low hills. It is suitable for tropical climate and is afraid of frost. Young trees will freeze to death when the temperature is-1 to 2 ℃. The average temperature for growth should be above 15 ℃ in summer. The cultivation and growth of sandy loam and clay loam with good drainage is better, and the soil pH value of 4.5 ~ 8.0 can be planted.

Propagation techniques of guava

1, grafting: generally choose this rootstock, when the seedling diameter reaches 0.7 cm, can be grafted, can use bud grafting or branch grafting method, the time is appropriate in winter and spring, the scion should not be too old or too tender, it is appropriate to just peel branches. The leaves were picked 10-15 days before scion collection, and the best effect was obtained when the buds were about to germinate. The rootstock is stout and accumulates a lot of nutrients, which is beneficial to the survival of grafting. Generally, the buds were unbound 1 month after grafting, and the buds healed and survived and cut the rootstock to promote the germination and growth of the scion, which could be planted in the nursery after 1 year.

2. Circle branch: the 2-year-old 3-year-old branch with a diameter of 1.2 cm 1.5 cm is selected and peeled around 40 cm 60 cm away from the top of the branch. The ring peeling width is 2 cm 3 cm, and the rooting medium is wrapped. Coating the ring with indole butyric acid aqueous solution or lanolin before rooting medium can promote early rooting, a large number of roots and a high survival rate. After 2 months, the new root was sawed away from the mother plant when the new root grew densely. Plant after sending new shoots twice and turning green.

3. Cutting: cutting cutting 2-3-year-old branches with a stem diameter of 1.2 cm to 1.5 cm, with a length of 15 cm, and cutting in February to April. Treating the base of cuttings with 0.2% indole butyric acid can promote hairy roots, and it is better to add 2% sucrose. It can also be treated with 0.2% naphthalene acetic acid and cut with leaves, and the effect is better under the condition of spray. After treatment, it was cultured in a 28032 ℃ cutter, and the rooting was fast and good.

Planting techniques of guava

1. Planting: the row spacing of early maturing varieties and poor soil of guava can be 4 × 4 m, while that of middle and late maturing varieties and fertile soil can be 6 × 4 m or 5 × 5 m. Combined with 80 cm deep and 80 cm wide planting holes, weeds, green manure, organic fertilizer and lime were buried in layers.

2. Backfilling: after planting and backfilling, guava should be more than 20 cm higher than the ground, and it is best to apply base fertilizer and backfill planting holes one month in advance, which is beneficial to the soil settlement of planting holes and avoid sinking after planting, which leads to planting too deep. After planting, cover the grass on the tree plate and pour through the root water. When there are too many tip leaves, part of the leaves can be cut off to reduce water consumption. Stand up a pillar after planting to prevent the wind from shaking and breaking twigs.

3. Pruning: after planting guava seedlings, the seedlings are cut off when they are 50-60 cm high to promote new shoots. 3 oblique branches with uniform distribution and suitable branching angle were selected as the main branches, the main branches were cut short by 30 cm to 40 cm, and 3 oblique branches were selected as secondary main branches. Then the fruiting branches were cultured on the main branch and the secondary main branch. In this way, a round crown with multiple main branches, dwarf tree shape and many effective branches can be formed.

4. Fertilizer and water: the fruit quality of guava is closely related to fertilization. There is a significant difference in taste between the fruit mainly applying organic fertilizer and the fruit mainly applying chemical fertilizer. In the first year of planting, 2 kg of ternary compound fertilizer, 1 kg of soybean bran, 0.2 kg of potassium sulfate and 0.5 kg of shell ash were applied per plant, and the amount of fertilizer applied in the second year was doubled according to the previous year. In the third year of planting, the amount of fertilizer application will not be increased or can be increased according to tree potential and yield.

① young trees: generally fertilize twice for each time the new shoots are cultivated, once when the new shoots sprout and when the new shoots are 40 cm long, each plant is treated with rotten manure or bran water plus 2.5-5.0kg urea liquid fertilizer, or 25 grams of urea plus 50 grams of potash fertilizer.

② strong flower fertilizer: after each shoot cutting to promote flower, guava is applied ternary compound fertilizer, accounting for 30% of the annual fertilizer application, and 1 kg of lime powder.

③ fruit protection fertilizer: during the growing period of guava fruit, ternary compound fertilizer plus potassium sulfate was applied, accounting for 30% of the total amount of fertilizer applied in golden years.

④ fruit picking fertilizer: the rotten livestock manure, farm manure or peanut bran is applied before guava fruit harvest, accounting for 40% of the annual fertilizer application, and chemical fertilizer is stopped at this time.

⑤ foliar fertilizer: guava was sprayed with 0.5% magnesium sulfate or 0.1% boric acid or 0.2% borax solution twice in the green stage, flower bud stage and young fruit development stage, with an interval of 7 days or 10 days, or topdressing outside the root according to the lack of elements.

5. Diseases and insect pests: the main diseases and insect pests of guava are canker, blight, nematode, anthrax, soot, fruit rot, pink scale, cotton aphid, peach fruit moth, whitefly, aphid and yellow thorn moth, etc.

① canker and blight can be prevented and treated with Bordeaux pulp (1 part of copper sulfate, 2 parts of hydrated lime and 3 parts of cow dung).

② anthracnose, coke rot and soot can be controlled with 50% Dysen zinc, 50% methyl thiophanate 1000 times, or 75% chlorothalonil 800x solution.

③ nematode disease is very difficult to treat once it is infected. Once the diseased plant is found, it should be removed or cut off and burned in time to prevent its spread.