Detailed Explanation of Main Pest and Disease Control Methods for Loquat
Loquat is evergreen year-round, blooms in autumn and winter, sets fruit the same year, and is harvested the following year. It begins blooming in September, and the flowering period lasts 2-3 months. If the flowers and fruit are protected through the winter (more than 10% of flowers and fruit), a bumper harvest can be achieved. However, from the time loquat is harvested in the current year (May-June) until the fruit is harvested the following year, various pests and diseases occur and cause damage,...
Loquat is evergreen year-round, blooms in autumn and winter, sets fruit the same year, and is harvested the following year. It begins blooming in September, and the flowering period lasts 2-3 months. If the flowers and fruit are protected through the winter (more than 10% of flowers and fruit), a bumper harvest can be achieved. However, from the time loquat is harvested in the current year (May-June) until the fruit is harvested the following year, various pests and diseases occur and cause damage, which affects loquat yield and quality. Based on the occurrence of loquat pests and diseases in the Luzhou area, the main pest and disease occurrence, damage, and control techniques for loquat from the flowering period to the fruit harvest period are introduced as follows.
I. Occurrence of Main Loquat Pests and Diseases
1. Flower cluster rot. There are many causes of loquat flower cluster rot, but the main ones are harmful organisms and climate. During the loquat flowering period (September-November), continuous autumn rain and high humidity accelerate the occurrence of flower cluster rot. Especially in the mid-to-late flowering period, the flower axis turns brown, soft, and rots into a mushy state. Squeezing the diseased part by hand causes a sticky liquid to flow out, and in the later stage the flower axis shrinks, dries up, and appears wilted.
2. Leaf and fruit diseases. According to a preliminary survey, the diseases damaging leaves and fruit include: brown spot, leaf spot, sooty leaf spot, ring spot, gray spot, anthracnose, black rot, brown rot, sunscald, and others. These diseases damage new shoot tender leaves and old leaves, and some can also damage flowers, flower clusters, young fruit, and so on. After young tender leaves are damaged, they curl and wilt, affecting the emergence of new shoots; after old leaves are damaged, large numbers of leaves fall; after fruit is damaged, brown round lesions initially form, rapidly expand around the navel end of the fruit, and finally rot until inedible, losing commercial value and greatly affecting yield.
3. Loquat pest mites. The pest mites damaging loquat leaves, tender shoots, and flowers are mainly oribatid mites. The number of generations of this mite per year in loquat production areas is unknown, but generations overlap. During the period when loquat summer shoots emerge, the population is relatively large and can seriously affect loquat flower bud differentiation. When flowers are damaged, they wilt and become soot-like, causing large numbers of flower clusters to drop.
4. Loquat yellow caterpillar. The loquat yellow caterpillar is the main pest of loquat. Its larvae feed on tender leaves and tender buds. When infestation is severe, even old leaves are eaten until only the veins remain, and it can even cause loquat trees to die. This pest occurs and causes damage from May to October. However, the greatest damage occurs from August to September.
5. Psyllids. Adult and nymph psyllids gather on new shoots, petioles, and leaves to suck sap. Damaged leaves have twisted veins, wrinkled leaf surfaces, and necrotic spots, and gradually turn black, inducing sooty mold and leaf drop.
6. Fruit borers. The fruit borers damaging loquat include the oriental fruit moth and peach fruit borer, with the oriental fruit moth being predominant. The oriental fruit moth has a broad host range. Its larvae bore into loquat new shoots, causing wilting; bore into the cluster axis and flower clusters, causing rot; and bore into fruit, causing fruit rot.
II. Loquat Pest and Disease Control Measures
1. Improving the loquat tree's resistance to pests and diseases is the basic measure for controlling pest and disease damage. Strengthen orchard management. After harvest, prune out excessively dense branches and bare-leg branches, and carry out thinning, renewal pruning, and short pruning. In particular, prune out diseased and pest-infested branches, suppress the growth of vigorous branches to slow their growth, so as to promote the emergence of summer shoots and lay the foundation for a bumper harvest the following year; control nitrogen fertilizer and increase phosphorus and potassium fertilizer, ensuring that vigorous trees are not given nitrogen fertilizer; improve drainage and irrigation systems, so that drainage is possible in the rainy season and irrigation is possible in drought. Young tree orchards generally should not be irrigated in July-August, and the tree should be loosened in time. Through these agronomic measures, the loquat tree's stress resistance can be enhanced and pest and disease damage reduced or alleviated.
2. Apply pesticide protection at the appropriate time to keep pest and disease damage below the economically permissible level. According to the annual growth phenology of loquat and the corresponding occurrence characteristics of pests and diseases, grasp 3 key pesticide application periods: The first is each shoot emergence period of loquat (spring, summer, autumn). The pests and diseases in this period include leaf-damaging diseases (gray spot, brown spot, leaf spot, ring spot, anthracnose, etc.), and the main insect pests are the yellow caterpillar, oriental fruit moth, and psyllids. Fungicides and insecticides can be mixed and applied: 43% Dasonfu 600-800 times plus 40% Julei 1000-1200 times mixed for application, or 43% Dasonfu 600-800 times solution plus 20% Haoniandong 1000 times or plus 4.5% Lubaishi 1000-1500 times; the second is the flowering period. This period is also the autumn shoot emergence period, and in addition there is continuous autumn rain, so there are many types of pests and diseases and the damage is severe, mainly flower rot, psyllids, oribatid mites, oriental fruit moth, peach fruit borer, and so on. 2% Jiashouhuo 500 times plus 40% Shijiale 1000-1200 times can be sprayed to control flower rot; 2.5% Tianwangxing 1500 times solution or 73% Guomanyuan 3000 times can be used to control mites; 43% Dasonfu 600 times or 25% Yebanqing 4000 times can be sprayed to control leaf spot, anthracnose, and so on; 40% Julei 1000-1200 times or 10% Anlubao 1500 times can be used to control psyllids, oriental fruit moth, peach fruit borer, and so on; the third is the fruiting period. Whether pests and diseases can be well controlled in this period is the key to increasing loquat production. The main diseases in this period include anthracnose, brown rot, and black rot, and the main insect pests include oriental fruit moth, peach fruit borer, stink bugs, and scale insects. The pesticides are the same as those used in the flowering period (so they will not be repeated here).
Once sesame-colored spot disease is found in young tree orchards and nurseries, the plants should be immediately pulled up and destroyed. In orchards where dry rot occurs, the diseased parts should be immediately scraped off and painted with 2% Jiashoumi 100 times. When white root rot and violet root rot damage the neck of loquat, use 71% Ailisha 800 times or 30% Aimiao 3000 times to drench the root area around the base.