Is it too late for autumn in September?
1. If the fertilizer and water conditions are good for the trees, it is not too late to produce autumn shoots in September, but it is necessary to grasp it quickly, and the latest batch of fruiting mother branches (autumn shoots) is generally budding before September 15-20.
2. Weak trees that are prone to drought, lack of fertilizer and water conditions or difficult to draw, or plants with too many hanging fruits, it is not recommended to put another batch of autumn shoots in September.
3. In the southern region of Guangxi (Nanning, Guigang, Yulin, Wuzhou South District, Hezhou South Piece, etc.), orchards with good fertile water and good fruit and water with early fruiting and strong trees, late summer shoots (drawn in mid-to-late July) are ripe, seize the time to put autumn shoots, suitable for pruning in early September (pick and cut thick late summer shoots), sufficient fertilizer water to promote strong shoots.
4. In the northern area of Guizhong (Liuzhou, Laibin, Hechi, Guilin, etc.), the semi-old fruiting trees in early autumn are not suitable for promoting their maturity, and then cut and put a batch of new shoots as the next year's fruiting mother branch.
5. Pruning should be mainly light shearing and thinning. First, thin the dense branches of the closed plant to ensure that the tree body is permeable to wind and light. Then the late summer or early autumn shoots that are ripe or mature are topped.
Be careful not to take off all the tops, do not cut the round head, go with the flow, choose the middle and upper branches with thick branches, thick green leaves, and long late summer tips for picking or topping, retain weak, short and thin late summer shoots, and increase the number of fruiting mother branches. At the same time, the use of long summer tips to improve to create a three-dimensional layered tree type.
Still fruiting in September?
Reason 1: "overload" is serious:
Just like the small horse-drawn cart will soon be tired, to the expansion period and color change period, need to consume a lot of nutrients, especially the trace elements boron, zinc, calcium, etc., uneven nutrient distribution will cause the mother tree self-regulation, causing a large number of fruit drop.
Reason 2: The tree is too strong:
Due to excessive vegetative growth, a large amount of nutrients are over-consumed by branches, the power of puffing fruit and color change period is insufficient, and the fruit competition for fertilizer is serious.
Reason 3: Single nutrition:
At present, the management generally has "heavy output, light quality." Heavy inorganic, light organic. Heavy in large quantities, slight amounts. Heavy underground, light above" undesirable phenomenon, affecting the balanced absorption of nutrients, inducing deficiency diseases and causing fruit drop.
Reason 4: Neglect of prevention:
Due to uneven nutrition, poor resistance and serious diseases, the tree body has not done disease prevention and nutritional supplementation in advance, especially acute anthrax, stem rot and other diseases are easy to cause a large number of fruit drops.
Reason 5: Improper medication:
During the visit, it was found that some farmers used mineral oil mixed with high-content metal ion foliar fertilizer and fungicides, which caused light damage to the fruit surface and serious direct fruit drop.
Reason 6: Abuse of regulators:
Some regulators puff fruit when the concentration is low, and directly thin the fruit when the concentration is high.
Reason 7: Weather Impact:
When there is too much or insufficient rainfall, nutrient absorption is hindered, affecting the growth and differentiation of fruits and branches, coupled with large temperature difference between day and night and poor root system in some places, the poor tree posture aggravates the split fruit and fruit drop.
It's September, what should I do if the fruit is small?
Generally, we say that the fruit expansion period of citrus will be concentrated in June ~ September, and now it is September, which is also the last sprint period of puffed fruit, but we found that there are some orchards whose fruits are much smaller than other people's fruits, what is the reason?
1. Lack of fertilizer
In summer and autumn, citrus extracts a large number of new shoots, as well as fruit development, requires a lot of fertilizer, if the fertilizer supply is insufficient at this time, it will have an impact on the development of young fruits and new shoots. Potassium is the element we know plays a key role in the puffing stage, it can promote cell expansion and fruit sugar accumulation, and puff fruit sweetening.
During the puffing period, citrus' demand for potassium is maximum. In addition, there is phosphorus, which promotes cell division, and the more cells, the larger the fruit. Of course, trace elements such as calcium, magnesium, and boron are also indispensable.
2. Too many fruits, intensifying competition
If the number of fruits is greater than the number of fruits that the citrus tree can provide, it is easy to cause nutrient competition between fruits, and there may be large and small fruits, or the overall stunted development of fruits.
3. The inner chamber is shaded and the nutrients are insufficient
If the inner branches of the fruit tree are too dense and too dense, resulting in shade in the inner chamber, it is difficult for the inner breech fruit to receive sunlight, which is easy to lead to poor fruit development.
4. The fruit is weak and difficult to grab nutrients
If the mother branch is relatively weak and slender, it is difficult to supply nutrients to the citrus, resulting in the fruit becoming a disadvantage in the nutritional competition and becoming a small fruit.
5. Contradictions between the fruit and compete for nutrients
A large number of hair extraction in summer and autumn, especially the extraction of summer tips, competes with the fruit for nutrition, aggravates the contradiction between the fruit and the fruit, resulting in poor fruit development in the early stage and small fruit in the later stage.
Remedy:
1. Fertilizer: If the fruit is small, it is generally necessary to supplement potassium fertilizer at the end of June at the latest, but now it is September, although it is late, but it is still necessary to carry out compensatory fertilization, it is recommended to apply Dayikang + root management, if accompanied by autumn tips turning green is not good, etc., you can use the application of Dayikang.
2. Fruit thinning: For trees with too many fruits, it is still necessary to remove the overly dense fruits to ensure that other fruits have sufficient nutritional development; For the inner breech fruit affected by the shade problem, the overly dense branches should be removed to ensure that the inner chamber is ventilated and transmitted.
3. Water management: It should also be noted that from the last fruit expansion period from September to October, if there is dry weather, there will be a lack of water, resulting in physiological growth disorders of trees and hindered fruit growth. And water management is also closely related to split fruit, so be sure to do a good job of water management during this time, it is best to combine water-soluble fertilizer, water and fertilizer supplementation.
What fertilizer is used for a little fertilization in September and autumn?
In September, after the application of base fertilizer, water-soluble fertilizer should be used as the main to ensure the coloring demand of puffed fruit, as for the top dressing of fruiting trees, according to the tree potential, fruit size to determine the amount and type of fertilizer, wolfang, maugu orange, emperor mandarin and other miscellaneous oranges can be reapplied puffed fruit; Varieties such as sugar oranges should be fertilized reasonably according to the fruit situation.
1. Plants with too many fruits and small trees should increase the application of water and fertilizer.
2. Plants with few fruits and large trees and strong trees, save fertilizer and promote tipping to avoid large fruits.
3. For plants that are semi-mature in early autumn (early August) and it is too late to put a batch of new shoots, fertilization should be reduced, including the spraying of foliar fertilizer, without pruning, so that these shoots are naturally ripe, and only branch disease and pest control can be carried out.
4. At this stage, plants with deviation of tree posture, thin and yellow fruit skin, and easy to crack fruit, it is best not to spray pure potassium or ultra-high phosphorus potassium fertilizer alone, and beware of thin peel and cracked fruit and floating skin in the later stage.
5. Gong mandarin (emperor mandarin), Maogu mandarin and other varieties with serious fruit drop in the later stage, potassium fertilizer and organic water-soluble fertilizer can be reapplied once in September.
6. Foliar fertilizer spraying, the resulting trees are mainly organic water-soluble fertilizer + calcium and magnesium medium trace element fertilizer.
What pests and diseases should I watch out for in September?
1. Insect pests:
The ambient temperature and growth period in September are suitable for the growth of psyllid, red rust mites, aphids, leaf latent moths, inchworms, etc., and longhorn beetle larvae should also be properly captured manually. It is necessary to check frequently and prevent and treat it in time.
(1) Control of citrus leaf moth: 0.5-2.5 cm in autumn, spray once every 5 days, a total of 3-4 sprays. Use of inulin agents to control citrus latent leaf moths.
(2) Prevention and control of citrus red spiders: 0.5-0.8 degrees stone sulfur blend, 95% engine oil emulsion 100~200 times liquid, 20% mite gram 1500-2000 times, etc. 2 times, the interval is 7-10 days, 15% tachymone 3000-4000 times liquid, local damage can pick and treat the central strain.
(3) Prevention and control of rusty ticks: commonly known as black charcoal round and cowhide orange. Pharmaceutical prevention and control: use 65% Daisen zinc 500-600 times liquid or 80% Daisen zinc 800 times liquid every 5-7 days to prevent again.
(4) Prevention and control of fruit sucking moth: In addition to harming citrus, fruit sucking moth is also harmful to a variety of fruits and vegetables such as peaches, pears, apples, grapes, etc., with September to October being the most intense. Put 500 times the dichlormid liquid and sugar water into a bowl and place it on a tripod set up around the orchard at night for booby-trapping. Orchards with power can also be booby-trapped with black lights.
2. Diseases:
The temperature in September, dry humidity is easy to form anthrax, ulcers and other diseases, because it is in the tender tip stretching and turning green, growth is fragile period, it is easy to be invaded by diseases.
(1) Canker disease: Canker disease can harm citrus leaves, branches and fruits, which is easy to prevent and difficult to treat. The lesion is nearly round, surrounded by a dark brown greasy outer ring and a yellow halo, and the center of the disease is often ruptured in the shape of a crater. Summer tips are the most serious, followed by autumn and spring. Once infected with fruit trees, they will carry the disease for life, and outbreaks will occur when the conditions are ripe.
The key points of prevention and treatment of canker disease: some susceptible varieties such as navel orange, orange, etc. should be prevented before; The pharmaceutical agent is mainly copper preparation, and inorganic copper preparations such as quinoline copper, thiambiomycete copper, copper rosinate, copper acetate are used in rotation with mesomycin. The best period for prevention and control is 15-20 days after the germination of new shoots, and pay attention to the peak period of incidence.
(2) Anthrax: Acute anthrax symptoms: Anthrax is divided into two types: chronic and acute anthrax, harming orange trees leads to weakening of the tree, and the whole tree dies in severe cases. Acute anthrax is boiling water with blurred margins; Chronic anthrax is typically characterized by concentric black dots arranged in concentric chakras, brown margins, and a clear junction between disease and health. It is easy to occur in the tender stage, young fruit stage and high temperature and high humidity weather.
The key points of anthrax prevention and control: strengthen cultivation management, increase the application of organic fertilizer, detect diseased shoots, and maintain the permeability of orchards; seize the critical period of prevention and control; Commonly used agents are: prochloramine, prochloraz manganese salt, manganese zinc, difenoconazole, chlorothalonil, pyraclostrobin, etc., which should be used alternately to slow down the occurrence of resistance.