Yellow rot disease caused by nematodes.

What are nematodes?

Nematode are invertebrates which can adapt to many different environments; that having a free-living form or a parasitic form on plants. The diameter of nematode is ridiculously small, about 1 mm; and can be observed under a magnifying glass or microscope.
The survival and development of nematode depends on various factors such as: Soil’s moisture, growth of roots, pH, oxygen in the soil, etc. Nematode can’t live in too dry soil, but they are living well in the soil with 100% moisture. If the roots are well developed, that willing to be high density of the nematode presented.

Nematode was isolated from tangerine trees soil in Dong Thap province

The tree growth on heavy and tigh clay soil, lack of water in the dry season, and flooding in the rainy, the roots are weakly developed.
Using a lot of chemical and less organic fertilizers made to reduce pH soil, useful microorganisms is gradually destroyed; Fungi and nematode are easy to develop in acid soil.
Farms having low-mound, high level of water or roots soil-filled, that makes the roots lack oxygen, plants are also susceptible to disease

Image of trees infected with nematode.

Nodules, rotten roots, underdevelopment, wilting, lack of vitality, twisted leaves, yellow-green leaves, defoliation.

To be able to prevent rot root on citrus, it is necessary to combine chemical and biological solution. NACENTECH HCM propose solution:

For trees that are suffering from nematode, it is necessary to cut off dry branch, so that the tree can focus on new buds.
Till the soil for ventilation then use fungicides, nematicides with active ingredients abamectin or azadiractin such as Tervigo 020SC or Agassi 36EC plus Nevo 330EC and Nacen Natracol.
After chemical methods, then needs to be used restorative and plant care products such as Humat seaweed, Nacen 06, Nacen Fulvic.

To prevent the development of many harmful fungi and nematodes; you should apply some long-term solution as follows: Increasing the application of decomposed organic fertilizers; supplement with biological products Trichoderma, Paecilomyces- metarhizium fungi as AT Astco to enhance beneficial microorganism for the root zone. It is necessary apply to lime power for controlling pH and limiting fungal diseases.