How to limit fruit drop disease on oranges?
(Baonghean.vn) - Nghe An orange growing areas are concentrated in the districts of Quy Hop, Nghia Dan, Con Cuong, Tan Ky... Currently, in these orange areas, the phenomenon of greening yellow leaves and fruit drop has appeared - a dangerous disease on orange trees.
According to the survey results of the Department of Crop Production and Plant Protection of Nghe An, up to now, the whole province has about 5,460 hectares of oranges, down 690 hectares compared to 2018, exceeding the development plan by 314 hectares. Of which, commercial oranges have 3,230 hectares, oranges in the basic construction period have 2,234 hectares.
To determinegreening diseaseor yellow leaf rot disease, recently plant disease experts from the Plant Protection Institute (Ministry of Agriculture and Rural Development) inspected orange gardens in Quy Hop, Nghia Dan and Con Cuong districts. On-site observations found that about 50% of the trees had symptoms of yellow leaves and rapid test kits gave the correct result of greening disease.
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| At this time, Vinh oranges in Quy Hop (Nghe An) are still in the development stage, but in many orange gardens, the oranges have fallen all over the ground. Photo: Xuan Hoang |
Those are only the plants that have yellow leaf symptoms. Plants that have not shown yellow leaf symptoms must be tested by PCR method in the laboratory for more accurate results and if done so, the percentage of diseased plants will be much higher.
The recent rapid test results to determine whether the orange trees have greening disease were conducted on orange orchards that were only 5-7 years old.
If tested on older orange gardens, the number of trees is likely to beinfectedThe greening will be much higher.
Orange greening disease, also known as orange vein yellowing, is caused by the gram-negative bacterium Liberobacter asiaticum that lives in the phloem of the tree.
The disease spreads rapidly through grafted eyes, rootstocks when propagating by asexual methods and through sucking insects as disease vectors, which are the leafhoppers. There is no specific treatment for greening disease on orange, tangerine and grapefruit trees.
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| Greening disease on orange trees. Photo: PV |
Orange, grapefruit, and tangerine trees that have been infected with this disease usually have the following symptoms: Leaves have yellow spots, yellow, green veins, small and rough leaves. Branches are short, leaves fall early, fall a lot, branches die and dry, causing the tree to gradually die. Fruits are small, have bad appearance, and are deformed and unbalanced. Roots gradually rot, making the ability to absorb water and nutrients poor.The fruit will fall.sometimes closer to harvest season as is happening now in the Phu Quy orange region.
One is:It is necessary to tighten the management of seedlings, absolutely do not allow the current situation of grafting, cutting, trading seedlings freely and floating on the market. If this situation continues, it will lead to the destruction of orange trees and the Vinh orange brand will also be greatly affected.
Two is:The Department of Agriculture in coordination with the Department of Agriculture and Rural Development of the districts needs to promptly conduct a general inspection and review of all orange gardens using both methods: Method of seeing trees with symptoms of yellow leaves and green veins, using a rapid test kit to correctly identify greening disease, and at the same time using a test kit applied to orange trees that have not shown symptoms of yellow leaves to determine whether there is a disease or not for timely treatment.
Three is: WhenIf you identify orange trees that have been infected with greening disease, you must resolutely destroy them to prevent the spread. If you regretfully try to restore them, it will only be costly, and they may still produce few fruits and the fruits will fall near the harvest season, as is happening now in local orange gardens.
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| Since the end of August, oranges have fallen en masse in orange gardens in Quy Hop district. Photo: Xuan Hoang |
The year is:Regularly check the orange garden, if you find leafhoppers on the branches of orange trees, use chemicals to spray and destroy them such as: Confidor, Admire 500 EC or Bassa 50EC combined with DC Tron Plus... spray periodically when the trees have new leaves, especially in spring or early rainy season, because leafhoppers often choose shoots and young leaves to lay eggs.
Why are Vinh oranges in Quy Hop falling more and more?
(Baonghean.vn) - Many orange growing areas in Quy Hop (Nghe An) - considered the capital of Vinh oranges - are losing more and more fruit, causing heartache for orange growers. Professional agencies have made initial assessments of the cause of the above phenomenon.
