<h1>Great harvest citrus plant protection</h1>
Before the main text, Tangerine Xiaomei would like to ask everyone, in the above 4 pictures, which are caused by zinc deficiency and which are caused by huanglongbing disease?
The citrus "cancer" of huanglong disease is actually not only that there is no medicine that can be treated, but the diversity of symptoms it shows, and the easy confusion with the symptoms of vegetarian deficiency, especially the above-mentioned zinc deficiency, increase the difficulty of prevention and treatment.
Therefore, Tangerine Xiaomei will share some ideas on the prevention and treatment of Huanglong disease with the research results of professors of South China Agricultural University on the pathogens of Huanglong disease just published in May.
<h1>Don't think of dragon disease as a deficiency</h1>
First of all, let's talk about the problem above, the four pictures are from the Network, and Tangerine Xiaomei feels that it is difficult to accurately judge only by looking at such pictures.
In the paper shared today, it is shown that mature leaves and old leaves on the primary branches of the Yellow Dragon Disease branch are mostly mottled, while the new leaves on the secondary branches are mostly uniform yellowing, zinc deficiency or atypical mottled. This seems to be similar to the fact that zinc deficiency in citrus often begins to yellow from the new shoots and new leaves.
The picture shows the symptoms of the branches of yellow dragon disease selected in the paper
According to the paper, the researchers selected 110 shoot samples with 2 to 3 typical symptoms of huanglongbing disease for testing, of which 53 samples detected the pathogen of huanglongbing disease, and 17 of the diseased samples had symptoms of zinc deficiency.
Therefore, in the planting process, if you encounter symptoms of suspected zinc deficiency, or other symptoms of mottled yellowing, if the treatment is ineffective, you may have to consider whether you are harmed by huanglongbing disease.
<h1>Huanglongbing cannot be judged only by the typical symptoms</h1>
The typical symptoms of huanglongbing disease, which we are generally familiar with, are as follows:
(1) The leaves are mottled and yellowed
(2) Leaf hypotrophic yellowing
(3) "Red Nose Fruit"
But from the latest research, citrus tissues that exhibit typical symptoms of yellow dragon disease do not necessarily have the highest levels of pathogens. Among the citrus tissues detected in the paper, citrus fruits showing the symptoms of "red nose fruit" had the most pathogenic bacteria; on the same branch, the old leaves showing typical mottled symptoms were less pathogenic than on the new leaves that were fully unfolded.
This is actually because the bacteria of yellow dragon disease have the characteristics of transferring from old leaves to new leaves and from leaves to fruits.
In addition, the symptoms of yellow dragon disease are also related to the condition of the citrus tree and the time it is located.
In general, the symptoms of trees with strong tree strength and various trees with sufficient micronutrients will be later and less obvious. In the spring and summer when citrus is growing vigorously, the symptoms of yellow dragon disease are usually not obvious.
Therefore, in the autumn and winter, it will become a high incidence of huanglong disease, but at this time, the more obvious symptoms of huanglong disease have been found to be much later than the time of infection with huanglongbing disease, which affects the timely treatment of huanglongbing disease trees.
Therefore, it is recommended that when you find suspected symptoms of huanglongbing disease, you should use professional methods to detect and identify as soon as possible, and prevent and treat them in time to reduce losses.
<h1>Why do you get Xanthalos lycophea</h1>
As we all know, Citrus Xanthorax disease in China is transmitted by citrus psyllids, and recent studies have also found that teak lice can also transmit Xyrosaurus disease.
We only know that these psyllids will spread yellow dragon disease, but in fact, they will spread yellow dragon disease in a large area, which is also the "intentional" of yellow dragon disease bacteria.
The gene expression of plants affected by yellow dragon disease changes, induced by pathogenic bacteria to produce some substances that attract citrus psyllids, and in order to cater to the yellowing characteristics of citrus psyllids, the leaves are yellowed, attracting citrus psyllids to feed and lay eggs. After the citrus tree gets sick for a period of time, the nutrients of the orange tree will be blocked, the growth and development will be stunted, and some substances will be produced to force the citrus lice to be transferred to other healthy plants. At this time, because citrus psyllids have carried a large number of germs, the process of feeding has led to the widespread spread of yellow dragon disease, forming a vicious circle.
For the citrus wood lice, the "puppet" of yellow dragon disease, everyone must not be merciful.
Studies have shown that the carrier disease transmission ability of adult citrus psyllids is weaker than that of nymphs, and nymphs aged 3-5 years can carry bacteria and diseases for life, so the prevention and control of yellow dragon disease also focuses on the control of citrus psyllid nymphs. Citrus psyllid nymphs peak in July and September, and the highest proportion of bacteria are carried in December and January, so it is important to pay attention to these two periods.
In addition, some studies have pointed out that too high citrus planting density will make the spread of citrus carwood lice more convenient, and the probability of citrus susceptibility is higher; citrus with high varieties also shows a higher chance of susceptibility.