If you missed fertilizing in autumn, how should you remediate apples in the Loess Plateau growing area in spring?

Apples are the largest fruit in my country, and the apple production in the Loess Plateau production areas accounts for a larger share of my country’s total apple production. In the Loess Plateau production areas, it is common to miss the application of base fertilizer in autumn. , large temperature changes in spring, drought, lack of rain, and poor pollination have affected apple yields in this area and caused economic losses to fruit farmers. Therefore, it is necessary to take some remedial measures to improve the quality and efficiency of apple production.

1. Spring fertilization is very critical, and there are ways to fertilize

1. The importance of spring fertilization

In the apple-producing areas of the Loess Plateau, spring fertilization is very critical. . Many fruit growers may have questions. Fertilization is important, and the most important thing is applying base fertilizer in autumn, right? Because the fruits have just been picked at this time, a large amount of nutrients are taken away by the apple fruits, so autumn fertilizer must be applied immediately to restore the weak tree vigor and lay the foundation for the second year's production. But why is spring fertilization so critical in the Loess Plateau production areas? This is because many fruit farmers in this area do not have the habit of fertilizing in autumn or do not have time to fertilize in autumn, leaving this most critical meal for apples.

Due to missing the application of base fertilizer in autumn, the apple tree will easily become weak in spring next year. In the words of local fruit growers, the tree has no energy, and a tree without energy will not have the strength to grow. Leaves and flowers bloom, but if the flowers bloom poorly, you will not be able to produce big, sweet apples in the fall, let alone guarantee the yield and quality. Therefore, the more boring the tree, the more important it is to fertilize the fruit trees in spring. For apple-producing areas on the Loess Plateau, spring fertilization is not "scrap copper and rotten iron", but "golden pimples".

2. The fertilization method should be particular.

If basal fertilizer is not applied in autumn, when fertilizing in spring, it should be under the canopy and 0.8 meters away from the trunk, radially along the horizontal root growth direction. Dig 6 to 8 fertilization trenches, 30 cm wide and 20 cm deep. Of course, the more the better, labor permitting, so that the spring fertilization can be absorbed and utilized by the fruit trees to the maximum extent.

We often say that fertilizer and water are inseparable. Fertilizer needs water to be absorbed by the roots and transported to various organs of the plant. The Loess Plateau is short of water. Therefore, we can only dig more trenches to let the fertilizer go. Spread as much as possible to improve fertilizer utilization. There is no need to dig a hole too deep. 20 centimeters is a suitable depth. At a depth of 20 centimeters, apple trees have the most fibrous roots. Therefore, fertilizing at this depth can allow the roots to quickly absorb fertilizer and provide timely supply for the germination of fruit trees in spring. Nutrient supply.

3. Be particular about the type of fertilization

Due to the low temperatures in early spring on the Loess Plateau, the activity of the root system has not been fully stimulated, and the activity of the root system is not high, and the absorption and utilization of fertilizers are difficult. The efficiency is relatively low. Therefore, in order to improve the utilization rate of fertilizers, we must first nourish the roots and then apply fertilizer. What depends on nourishing the roots? Bio-organic fertilizer, through the application of bio-organic fertilizer, improves the root system's ability to absorb and utilize fertilizer.

The use of chemical fertilizers is also very particular. Fruit trees have different nutrient requirements at different stages of their annual growth. Fruit trees have two metabolic types in the annual cycle, namely nitrogen metabolism and carbon metabolism. These two metabolic types determine the accumulation and consumption of nutrients in the tree. In the early stage of vegetative growth, nitrogen metabolism is the main consumptive metabolism. At this time, the absorption and assimilation of nitrogen fertilizer is very strong, branches and leaves grow rapidly, and organic nutrients are consumed but accumulated little. Therefore, the requirements for fertilizer and water, especially nitrogen, are particularly high.

Therefore, the most important thing in early spring is to add more nitrogen fertilizer to fruit trees. The absorption of nitrogen by fruit trees is higher at the beginning and lower at the end. On the premise that there is no base fertilizer applied in autumn, the first fertilization in spring requires high-nitrogen fertilizer to replenish the body of the fruit trees, so that the fruit trees can sprout new shoots and grow leaves. However, the demand for phosphorus during this period is not very large; The demand for potassium is just the opposite of nitrogen, low first and then high, or medium first and then high.

When choosing chemical fertilizers, it is recommended to choose apple-specific fertilizers with high nitrogen, medium phosphorus, and low potassium, such as apple-specific fertilizers with a nitrogen, phosphorus, and potassium ratio of 22-10-8. About 6 pounds of fertilizer per tree can meet the needs of the tree. The principle of fertilization is to apply more fertilizer to large trees and less to small trees.

The amount of fertilizer should be combined with the age of the tree and the three-year average yield, as well as the actual local conditions and under the guidance of experts.

When applying fertilizer for the first time in spring, the word "quick" is important. The fertilizer must be quickly absorbed by the tree. Therefore, the choice of nitrogen fertilizer is also very particular. Nitrate nitrogen can be directly utilized by fruit trees, while ammonium nitrogen or amide nitrogen needs to be converted into nitrate nitrogen before it can be absorbed by fruit trees. The ground temperature is low in spring, and the effect of using urea is poor. This is like eating steamed buns. After entering the human body, it needs to be digested for a while before it can be absorbed by the body. However, using nitrate nitrogen can be directly absorbed and utilized by the body like drinking glucose directly. Nitrate nitrogen is more easily absorbed and utilized than other types of nitrogen fertilizers.

3. Supplement nutrients to the tree through foliar fertilization

Fertilizing through the soil is like adding dinner to a weak fruit tree, but the ground temperature is low in spring and the root absorption capacity is reduced. Poor, even if the fertilizer applied can be directly used by the roots, there still needs to be a process after the fertilizer is applied, and the roots need to slowly absorb it. For the above-ground part, you can add some side dishes at this time to assist the roots in quickly absorbing nutrients.

Spray organic small-molecule water-soluble fertilizers containing fulvic acid, alginic acid, and amino acids directly onto the dry branches through foliar spraying, allowing nutrients to quickly enter the tree through the epidermis. Although the tree body can absorb relatively few nutrients, the nutrients absorbed through the lenticels can exert fertilizer effects faster and with higher efficiency.

2. Laying horticultural floor coverings

In spring, the biggest problems on the entire Loess Plateau are drought and water shortage. Therefore, it is particularly important to take certain measures to conserve moisture, including heat preservation and moisture conservation. , water conservation means ensuring production and efficiency. Fruit growers may think of mulch film, but what I would recommend to everyone is gardening floor cloth. Laying horticultural floor coverings has three main functions: Insulation effect: During the apple flowering and fruit-setting period, although the outside temperature has increased, the temperature changes in the Loess Plateau production areas are still relatively large. By laying horticultural floor coverings, the ground temperature can be increased1 ~2℃, although it is only 1~2℃, but don’t underestimate it, it has an important impact on flowering and fruit setting. Moisture retention performance is higher than that of mulch: The difference between gardening mulch and ordinary mulch is that it is cloth. Not only can it retain moisture, it also has some small holes. Rainwater can seep through these holes and gaps, while retaining moisture. Water storage, unlike ordinary mulch, can only protect underground water, but cannot accept external sources such as rainwater, and cannot accumulate moisture. Strong anti-aging ability: Compared with ordinary mulch films, horticultural floor coverings have another significant advantage: they are strong, anti-trampling, and anti-aging. They can generally be used for three years and can be used repeatedly, saving costs, manpower and material resources.

3. Ask Osmia Bees to help

In early spring, the application of high-nitrogen fertilizers and the laying of gardening floor coverings introduced earlier will promote the strong growth of fruit trees. When the fruit trees reach the flowering period, management It's even more critical. We all know that fruit can only bear fruit after being pollinated. Therefore, the flowering period of fruit trees is the most critical stage of management in the year. If pollination is not good during flowering, the fruit setting rate will be low, which will lead to a reduction in yield. There are a lot of flowers blooming, but no fruit. This is a problem encountered by many fruit growers during this period. To solve this problem, we need to ask Osmia for help.

1. Characteristics of the Osmia hornet

The Osmia hornet is also called the Osmia hornet, which belongs to the superfamily Apis and a genus of Osmia in the family Leafcutter family. The abdomen of the female wasp has multiple rows of neatly arranged abdominal hairs, which are called abdominal hair brushes, while the abdomen of the male peak has no abdominal hair brushes. These abdominal hair brushes are the pollen-collecting organs of the Osmia wasp. After the Osmia frontalis crawls over the flowers, The abdominal hair brush is covered with pollen. The horned Osmia bee reproduces one generation a year and does not require artificial feeding. They live in the nest tube for 320 days a year and only live about 40 days in nature. Taking advantage of this characteristic of Osmia bees, Osmia bees can be brought into the orchard during the spring flowering period. After pollination is completed, the bee tubes that lay eggs are collected and stored in the refrigerator for reuse in the next year. Fruit farmers make a one-year investment. Benefit every year.

2. The pollination advantages of Osmia bees

Using Osmia bees for pollination is not only because of its unique personality, but also because it has different pollination characteristics compared with bees.

Osmia pollination has the characteristics of fast pollination speed, good pollination effect, easy management, and can save a lot of labor costs.

(1) The activity temperature of Osmia bees is lower than that of bees

The activity temperature of Osmia bees is lower than that of ordinary bees. The temperature required for ordinary bees to move is 15~16℃, but The pollination activity of Osmia bees can be carried out at a temperature of 13~14℃, which is 2~3℃ lower than that of ordinary bees. This is very suitable for the pollination of fruit trees in the fruit areas of the Loess Plateau. Even though the temperature is only 2~3℃, it is still To a large extent, the occurrence of only flowers but no fruits is avoided.

(2) The number of flowers visited and the area visited are better than those of bees

At lower temperatures, Osmia bees are more diligent than bees and can feed three to four hundred flowers in one hour. Flowers are pollinated, but the average bee only has one or two hundred. At the same time, in the way of picking flowers, Osmia bees often have their entire body in contact with pollen or pistils, while bees stand directly on the petals with two legs and use their mouthparts to suck the honey inside. Therefore, Osmia bees have better contact with pollen. , thus ensuring the quality of pollination. Good pollination not only improves the fruit setting rate, but more importantly, it directly affects the quality of the fruit. Well-pollinated apples will have good fruit shape.

In addition, compared with artificial pollination, Osmia pollination also has great advantages. Studies have found that on Fuji apples, the fruit setting rate of Osmia bee pollination can be increased by more than 50% compared with manual pollination.

3. How to use Osmia bees

(1) Preparation for using Osmia bees for pollination

Pest control and re-pruning: First, bud the apple tree Before planting, it is necessary to do a good job in preventing and controlling diseases and insect pests, especially fruit tree diseases that require spraying to prevent, such as spraying lime sulfur mixture and other work should be carried out at this time. Two weeks before releasing the Osmia bees, no insecticides or fungicides can be sprayed. Secondly, after the fruit trees sprout, they must be re-pruned before flowering to thin out branches that are too strong or too weak to make the fruit branches bloom. The amount should be kept moderate, which will not only improve the fruit setting rate, but also enable the apple tree to bear a reasonable load.

Preparation of the hive: The above is the preparation before releasing the bees. Next, let’s talk about the preparation of the hive. When spring arrives, the bee tubes for egg laying are first prepared for the Osmia bees. Why do we need to prepare bee tubes? By artificially making bee tubes and placing them at the inoculation site, you can reduce the time Osmia bees spend searching for a place to lay eggs, save time, and pollinate the apple tree more. If you don’t put it there, Osmia bees will look for suitable places to lay eggs everywhere. , increasing labor intensity, thus reducing pollination time.

The production of bee tubes is very simple. You can use reed tubes or straight tubes. Taking reed tubes as an example, let’s talk about the production of bee tubes. Select a reed tube with an inner diameter of 0.6~0.8 cm. Cut the selected reed tube into a short tube of 15 cm. It is required that the knotted end is shorter. The cut of the reed tube should be smooth to avoid stinging the Osmia wasps. The cut reeds The tubes are bundled into bundles of 50 each and allowed to dry before use.

Hive erection: In the orchard, not all places are suitable for Osmia wasps to build nests. You should choose a sunny place in the orchard. And there should be a small open space in front of the nest. The selection of hive materials is relatively random, such as cardboard boxes, large water tanks, hollow bricks, etc. However, if conditions permit, it is best to set up a special beehive. Beehives are generally set up in the southeast of the orchard, 30 to 50 centimeters above the ground. The beehives are supported by wooden frames or bricks, and the beehive mouth faces south or west.

In the orchard where Osmia bees are first released, a hive should be set up every 30 to 40 meters. When the number of Osmia bees breeds increases next year, a hive can be placed every 40 to 60 meters and the beehives will be set up. Finally, put the prepared bee tube into the beehive, with the knotted end facing inward and the unknotted end facing outward, and cover the honeycomb with a plastic film to prevent rain. Then apply some waste engine oil on the hive bracket to prevent ants, plants and other natural enemies from invading.

Due to the relatively dry spring in the Loess Plateau, a mud pit must be dug in front of the nest for Osmia wasps to build their nests. Dig a pit 50 cm long and wide 1 meter in front of the hive, and water the pit to keep the soil moist. At this point, an environment suitable for the growth of Osmia is ready.

(2) Bee release time

The bee release time of Osmia bees should be determined according to the tree species and flowering period. Generally, it is advisable to release bees from 3 to 5 days after the central flower blooms.

(3) How to release bees

Take out the cocoons from the refrigerator and they are still in the reed tube, so we need to use a knife to split it from the middle and take out the cocoons. , place the cocoon in a small, wider cardboard box, poke holes with a diameter of 0.7 cm around it for the Osmia bees to crawl out, and then place the cardboard box in the hive. After the cocoons are placed in the orchard, the Osmia wasps will bite through the cocoons one after another and rush out of the hive. They can emerge in 7 to 10 days.

(4) Number of bees released

The number of bees released depends on the orchard area, tree species and fruiting status over the years. The number of bees to be released per acre in orchards during the fruiting period is 300 to 500, and the number of bees to be released per acre in young orchards during the early fruiting period and the year of low fruiting is 200 to 300 bee cocoons per acre.

In addition, it must be noted that the orchard cannot be sprayed during Osmia pollination to prevent Osmia poisoning. After the flowering period, the short life cycle of the Osmia bee is over, and its eggs are laid and dormant in the nest tube, waiting until the next spring to hatch out new Osmia wasps.

In spring, in the apple-producing areas of the Loess Plateau, by increasing the application of high-nitrogen fertilizers and laying horticultural floor coverings under the trees, the tree vigor can be restored to strength and the quality of flower buds can be improved. Then, Osmia bees can be used for pollination, which can improve the quality of flower buds. The pollination rate and fruit setting rate of apples not only make up for the deficiencies of regional climate and human factors, but also better ensure the yield of apples, thereby improving the quality and efficiency of apple production in the region.