Abstract: Loquat as a four-season evergreen plant, in the september to November of each year between september and November, can bear fruit that year, and can be safely overwintered with the fruit, generally in may of the following year can be harvested. Throughout the process loquat is often eroded by various pests and diseases. In this paper, by analyzing the main occurrence characteristics of loquat diseases and insect pests, several comprehensive control technologies and measures are elaborated on the basis of summarizing the experience of previous generations in view of several common diseases and insect pests common in the process of loquat from flowering to fruit harvesting. Details are as follows:
<h1 class= "pgc-h-arrow-right" > first, the characteristics of loquat disease occurrence </h1>
(1) Infectious diseases
For the current invasive diseases of loquat, the most common are the following three, which are anthrax, leaf spot disease and rot disease. For loquat fruits that have grown to a more mature state, the onset of anthrax can directly cause the fruit to rot. Leaf spot disease mainly infects the leaves of loquat trees, which will lead to the rigidity or wilting of leaves, affecting the normal development of loquats, and eventually causing loquats to fail to flower and bear fruit normally; Rot disease occurs more in the rhizome and main stem of the loquat tree, and the bark of the loquat tree infected with rot disease will have a serious cracking phenomenon, and when it is serious, it will directly lead to the death of the loquat tree.
(2) Physiological diseases
The first type of sunburn disease, the physiological disease mainly occurs in the fruit and branch of the loquat tree, healthy loquat fruit after infection with the sunburn disease, the side of the fruit facing the sun will be quickly burned and dry phenomenon, resulting in the entire loquat fruit can no longer continue to grow and use; The second common physiological disease of loquat is called leaf tip scorch blight, and loquat infected with this type of disease not only gradually yellows the leaf tip, cannot grow normally and makes the leaf expand downwards, and eventually directly becomes black scorched.
<h1 class="pgc-h-arrow-right" > second, the characteristics of loquat infestation </h1>
(1) Loquat yellow caterpillar
Loquat yellow caterpillar mainly harms the young leaves of loquat trees, which in turn seriously affects the normal growth and development process of the whole loquat tree. In addition, the larvae of the first generation of loquat yellow caterpillar will also harm the fruit of loquat, on the one hand, it will greatly affect the appearance of loquat fruit, and more seriously, it will directly cause a whole loquat fruit to lose its edible value.
(2) Pear small heartworms
As a common type of plant pest, pear heartworm is mainly concentrated in the phloem tissue of the fruit and branch of the loquat tree when it harms loquat trees. Once the pear heartworm attacks the fruit of the loquat tree, then these loquat fruits will directly lose their edible value; When the branches of the loquat tree are invaded by the small heartworm of the pear, the main manifestation is that the bark of the branch department is directly eaten clean, resulting in the inability of the whole loquat tree to grow and develop normally.
<h1 class = "pgc-h-arrow-right" > third, integrated control measures for common loquat pests and diseases </h1>
(1) Agricultural prevention and control technology
Combined with the pathogenesis characteristics and infection characteristics of several diseases and insect pests commonly seen in the growth and development of loquat trees, when cultivating and planting loquat, it is necessary to combine the actual climate of the local area and other external factors, and prevent problems by adopting relevant agricultural control techniques to stifle the diseases and insect pests that may be encountered in the cradle. First of all, after the harvest of loquat fruit in the previous season, the grower needs to combine the actual growth status of the loquat plant, and while fully summarizing the planting experience of the previous season, re-trim the loquat, including sorting out the intricate branches, cutting out the overly long and weak branches, as well as the branches that are cross-entangled and the branches that have been infected with diseases and insect pests; Secondly, when the loquat new shoots have just germinated, appropriate sprouting measures should be carried out, that is, the relatively weak seedlings should be eradicated, and only robust young shoots should be retained as much as possible, and the general specification is to retain a new shoot at an interval of about 35 cm; In the autumn, secondary wholeing is also required, mainly to prevent the branches from being sealed, and some perennial or thicker branches need to be moved out and retracted, usually the distance between loquat plants is at least more than 60 cm. Through the use of scientific and reasonable agricultural control measures, not only can effectively prevent loquat plants from being eroded by diseases and insect pests, but also promote the healthy growth of loquat to a certain extent.
For example, in view of the fact that loquat fruits are often susceptible to infestation from different kinds of diseases and insect pests, planters should use scientific agricultural control techniques in the daily planting process of loquat to maximize the possibility of different diseases and insect pests causing harm to loquat fruits. Generally speaking, when a large area of loquat plants appears to bear fruit, the planter needs to thin the fruit in time, that is to say, the loquat fruit that does not grow well or is too dense should be directly removed in time to ensure that other loquat fruits can have sufficient nutrients for later development; Secondly, after the fruit thinning is completed, the fruit can also be isolated from the outside world to a certain extent by adopting the classic agricultural control technology of bagging, and the possibility of external viruses and insect pests approaching the fruit can be controlled to the greatest extent. Through the two technical measures of fruit thinning and bagging, on the one hand, it is to reserve a more adequate material basis for loquat fruit, on the other hand, to build a healthier external space for the growth and development of loquat fruit, and the combination of the two can jointly and effectively promote the healthy growth of loquat fruit.
(2) Physical and biological control techniques
First, physical control technology, through a large number of practical experience can be found that many pests have a certain degree of suspended death, so in the prevention and control of loquat diseases and insect pests can fully combine this characteristic of pests, in the morning or evening when vigorously shaking the loquat trunk, after shaking the pests and then carry out centralized artificial killing will achieve the effect of half the effort. The second is biological control technology, in recent years, biological control with its non-polluting, non-toxic and harmless and other characteristics in the field of agricultural control and other applications are more and more extensive, the so-called biological control technology is actually focused on the self-regulation of nature, through the use of natural predators and other control of diseases and insect pests. Moreover, compared with other control technologies, biological control technologies are more green and environmentally friendly. For example, in the case of a small pear heartworm commonly found in the cultivation process of loquat trees, this pest not only erodes the loquat fruit, but also causes damage to the loquat branches. In the process of control, the control measures of sexual attractants in biological control technology can be used, and the use of certain sexual attractants can not only kill a large number of small heartworms of this type of pear, but also interfere with their mating laws and affect their normal growth and breeding, so as to achieve effective control purposes.
(3) Chemical prevention and control technology
The so-called chemical control technology refers to the control of diseases and insect pests through chemical pesticides and other measures to a certain extent. Compared with the previous disease and pest control technologies, the pollution degree of chemical control technology is higher, especially some high concentrations of chemical pesticides not only have a control effect on pests and diseases, but also cause a certain curbing effect on the normal growth of loquat plants. However, when loquat trees are facing a relatively large and high-intensity pest infestation, chemical control techniques will be more effective and efficient than other technologies.
For example, in the process of prevention and control of anthrax and leaf spot disease, if the two diseases spread very quickly, appropriate chemical control techniques can be used. Generally speaking, it is necessary to use 25% leaf spot clear chemical solution and dilute it to 4000 times, plus 10% annulo solution after dilution 1500 times, and carry out large-scale disease control by spray spraying. In addition, if the degree of disease is very serious, the concentration of the agent can be appropriately increased or sprayed again after three days.
<h1 class="pgc-h-arrow-right" >4 </h1>
The erosion of pests and diseases not only affects the normal growth of loquat, but also has a direct impact on loquat production. Therefore, in the whole process of loquat flowering to fruit harvesting, it is necessary to summarize the occurrence characteristics of different diseases and insect pests and choose appropriate control measures to ensure the healthy growth of loquat.