Winter Management Methods and Technical Key Points for Shatang Mandarin
AbstractAfter clearing the weeds in the orchard and covering them on the tree disc, or digging a trench below the drip line of the canopy, filling the trench with soil-organic fertilizer or weeds and then sprinkling lime powder, using the weeds to compost and improve the soil quality. In winter, do a good job of disease prevention and cold resistance for the fruit trees. You can also adopt ring girdling, root cutting, fertilization, hormones and nutrients to promote flowering, but pay attention to water control. At the same time, strengthen the cleaning of the plantation to provide a good growing environment for the fruit trees and help them overwinter smoothly.
In winter, the temperature is relatively low. To help the shatang mandarin trees overwinter smoothly, you can clear the weeds in the orchard and cover them on the tree disc, or dig a trench below the drip line of the canopy, bury soil-organic fertilizer or weeds in it, and then sprinkle lime powder on top, improving the soil condition by composting the weeds.
After removing the weeds, the winter sunlight and low temperatures can eliminate some of the disease and pest sources left on the surface soil.
If frost occurs frequently in winter in the local area, prepare clean water and promptly wash off the frost remaining on the leaves. Also spray brassinolide on the canopy in advance to improve the cold resistance of young trees and ensure they overwinter smoothly.
Winter Management Methods for Shatang Mandarin
1. Disease prevention and cold resistance
After digging trenches and applying winter fertilizer to young trees in January, mound soil on the tree disc around the drip line of the canopy. Mix 35-40 jin of quicklime, 0.5 jin of table salt, 2 jin of lime sulfur mixture and 100 jin of water evenly, then whitewash the trunks, and sprinkle some lime powder to improve the soil quality, maintain soil temperature and prevent diseases and pests. If there is frost, promptly clean the frost off the leaves, and also spray brassinolide on all of them in advance to enhance the cold resistance of the shatang mandarin trees.
2. Ring girdling to promote flowering, root cutting and water control
If next year fruit setting is planned, for orchards with sufficient fertilizer, abundant water and good tree vigor, ring girdling can be used to promote flowering, but during operation pay attention to controlling the strength and position. Do not make it too deep or too wide. After ring girdling, disinfect the girdling wound properly.
At the same time, do a good job of root cutting to promote flowering. 7 days before applying winter fertilizer, hoe a 10-20 cm trench around the tree 20 cm outside the drip line of the canopy to cut the tree roots, and also manage water control well to promote flower bud differentiation.
3. Fertilization to promote flowering
Mainly apply organic fertilizer. You can also appropriately add some potassium sulfate compound fertilizer, medium and trace element fertilizer and calcium magnesium phosphate fertilizer. If the trees grow weakly and the leaves are yellow, apply more potassium fertilizer to improve them.
4. Hormone promotion of flowering
When the autumn shoots begin to mature, spray paclobutrazol to prevent winter shoots from emerging and damaging reproductive growth and affecting flower differentiation. You can also alternately use brassinolide, prohydrojasmon, cytokinin, 2,4-D and other flowering-promoting hormones to promote flowering. Generally, spray prohydrojasmon once each in December and January. In late December or early January and during the first fruit preservation, spray cytokinin twice. After December, spray brassinolide once a month.
5. Nutritional promotion of flowering
In November, December or January after the autumn shoots mature, spray astaxanthin twice. From late October until before flower formation, spray amino acid foliar fertilizer with high phosphorus, high potassium, high calcium and high boron twice.
Potassium and calcium have an antagonistic effect on trees. Using too much can easily burn the seedlings. It is best not to use amino acid calcium or humic acid calcium at the same time either, so as to avoid excess nutrients, which can also affect tree growth and development.
If you want to supplement calcium for the trees, it is best to choose buried base fertilizer. If foliar spraying is needed, choose mannitol calcium, or other calcium that is relatively neutral and mixable.
6. Strengthen orchard cleaning
Cleaning the plantation can improve the vitality of the tree body, add a protective film to the tree surface, strengthen the tree body's ability to resist cold, freezing, frost and pathogens, and promote the safe overwintering of the fruit trees.
After picking the fruit, in late winter and early spring before budding, clean the orchard twice, generally once every about 20 days. Remove or deeply bury the dead branches and rotten leaves in the orchard, and spray pesticides on the whole trees, ground and weeds throughout the orchard.
For the first time, you can spray lime sulfur mixture for mite control together with nissol thiazolidinone to kill insect eggs; or spray propargite for mite control together with isocarbophos or fenpropathrin or amitraz to kill mites and insect eggs. You can also add and spray some flowering-promoting foliar fertilizer.
For the second spraying, use Luying mineral oil to kill insects, mites and fungi, and spray it together with brassinolide and amino acids. If it is a warm winter, the early insects may have already awakened, so you can add avermectin, imidacloprid, etc. to spray and kill insects.