Alternate intercropping cultivation method for effectively preventing and controlling tetranychus cinnabarinus of cassava

Abstract

The invention discloses an alternate intercropping cultivation method for effectively preventing and controlling tetranychus cinnabarinus of cassava. The method specifically comprises the following steps: 1) planting in the first year, interplanting cassava and Chinese mesona herb (corn) in proportion, performing field management, and harvesting; wherein the Chinese mesona herb and the cassava are firstly planted in spring, the corn is planted in autumn after the Chinese mesona herb is harvested, and finally the corn and the cassava are harvested; (2) during planting in the second year, cassava and Chinese mesona herb (corn) are planted by adopting an alternate intercropping method; one alternate intercropping period is two years, and cassava, mesona chinensis and corn are planted in turn in the same planting zone. According to the method, interannual crop rotation is achieved through alternate intercropping cultivation, soil continuous cropping obstacles can be relieved, soil health is kept, strong seedlings are cultivated, the growth vigor of cassava is enhanced, and the disease and pest resistance of cassava is improved; meanwhile, natural enemies can be protected, the life cycle of diseases and insect pests is disturbed, the occurrence rate of the diseases and insect pests is reduced, accordingly, tetranychus cinnabarinus is reduced, and agricultural control over the tetranychus cinnabarinus in the cassava field is

Description

Technical Field

[0001] The invention belongs to the technical field of agricultural planting, and particularly relates to an alternating intercropping cultivation method for preventing and controlling cassava spider mites. Background Art

[0002] Cinnabar spider mites are the most common mite pests in cassava cultivation. They usually gather on the back of the middle and lower leaves to suck juice. In the early stage, the affected leaves will have chlorotic spots on the leaf surface, which will gradually become continuous. In the later stage, the damage will cause a large area of ​​yellow-brown. When the damage is serious, the whole leaf will turn yellow and look like a burnt fire, causing early leaf fall and premature aging and death of the plant. The damage caused by this mite can cause a 20-70% reduction in cassava production, and when the damage is serious, it can lead to a total crop failure. Cinnabar spider mites mainly gather on the back of cassava leaves and both sides of the veins to suck juice. Because of their small size, fast reproduction, and overlapping generations, eggs, nymphs, and adult mites will appear in the same period, greatly increasing the difficulty of prevention and control. At present, the prevention and control of cinnabar spider mites in China mainly relies on the use of chemical pesticides. Although traditional chemical control methods have controlled pests to a certain extent, they have also brought about problems such as drug resistance, chemical pollution, and ecological environmental damage, increasing the cost of agricultural production and reducing benefits. If effective prevention and control measures are not taken, the large-scale occurrence of cinnabar spider mites will lead to a significant drop in cassava production and affect farmers' economic benefits. At the same time, the large-scale use of chemical pesticides will not only cause environmental pollution, but also kill beneficial insects that are sensitive to pesticides, further deteriorating the ecological environment of cassava fields. And because the insect is small in size, occurs in large quantities, and feeds in a hidden way, the cost of prevention and control is high, which reduces the benefits of planting cassava. Therefore, exploring and developing efficient and environmentally friendly agricultural prevention and control measures to achieve the goals of protecting natural enemies, reducing the use of chemical pesticides and improving the prevention and control effect is of great practical significance for achieving sustainable agricultural development. The use of cassava and agar grass (corn) alternating intercropping technology can effectively reduce the occurrence of cinnabarinus spider mites, avoid or reduce the application of chemical pesticides in cassava fields, effectively prevent chemical pesticides from polluting the environment, reduce prevention and control costs, improve land utilization and planting income, protect natural enemies, and maintain the balance of the cassava ecosystem. Summary of the invention

[0003] In view of the above problems, the present invention provides an alternating intercropping cultivation method for effectively preventing and controlling cassava cinnabarinus spider mites, aiming to effectively control the damage of cassava cinnabarinus spider mites, while reducing the use of chemical pesticides and protecting the ecological environment.

[0004] The present invention is achieved through the following technical solutions:

[0005] An alternating intercropping cultivation method for effectively preventing and controlling cassava spider mites comprises the following steps:

[0006] (1) Intercropping spacing planning: intercrop cassava, agar grass or corn in a 2:3-4 row ratio;

[0007] (2) Site selection and land preparation: Select flat or gently sloping land with loose and deep soil, medium or above fertility, convenient drainage and irrigation, and suitable for continuous planting; plow the land, mix all the base fertilizers, evenly spread them on the surface, and plow them into the soil; harrow the soil and then make ridges according to the planting specifications, with a ridge surface width of 90-110 cm, a ridge bottom width of 130-150 cm, a ridge height of 25-35 cm, and a ridge bottom width of 40-50 cm; every 667 m 2 Apply 500-800kg of biological organic fertilizer or 1000-2000kg of decomposed farmyard manure, 40-50kg of phosphate fertilizer, and 30-40kg of compound fertilizer;

[0008] (3) Selection and planting of cassava seed stems: Planting should be carried out in March or April of the same year when the daily average temperature is ≥18°C; fully mature and lignified main stems or primary branches should be selected as seed stems, with a length of 15 to 20 cm; and cassava should be planted according to the row spacing specifications;

[0009] (4) Cutting seedling cultivation and planting of agarwood:

[0010] a. Planting time: intercropping agar grass and cassava should be planted at the same time, or agar grass should be planted first and then cassava should be planted 10 to 15 days later;

[0011] b. Cutting seedlings: In spring, when the temperature rises steadily to above 15°C, cutting seedlings can be carried out; first, level the field and place the seedling trays in rows for standby use; add 25 to 30 g of 50% wettable carbendazim powder to every 1000 kg of field topsoil, mix it with water to form a slurry, put it into the seedling tray, and flatten it; then, cut the strong, disease-free and insect-free tender stems from the wintering agarwood mother plant as cuttings, each cutting is 5 to 8 cm long, leaving 2 to 3 nodes and 1 pair of top leaves, soak the cuttings in 1000 times 50% wettable carbendazim powder for 3 to 5 minutes, and immediately carry out cuttings into the seedling tray after taking them out;

[0012] c. Management measures for cutting seedlings: When the temperature is ≤15℃, build an arch shed and cover it with white film for heat preservation; when the temperature is ≥25℃, cover it with a shade net with a shade degree of 40-50% to prevent sun exposure and cool down; 5-6 days before transplanting, remove the covering; water to maintain soil moisture at 60-70%; remove weeds in time to keep the seedbed clean; 15 days after cutting, irrigate once every 7 days with 0.1-0.2% urea solution;

[0013] d. Transplanting and planting: 20-30 days after cutting, when the cuttings are growing healthily, transplanting can be carried out; 1 day before transplanting, water the seedling tray thoroughly and lift the seedlings with soil; spread the ground film on the ridge surface and compact it with soil around; when planting, break the film and dig holes according to the spacing between plants and rows, put the seedlings vertically into the holes, cover the holes with soil and compact it, and the seedlings should be exposed outside the ground film; after planting, water the soil enough to establish roots, and water it every day to keep the soil moist;

[0014] (5) Field management of jelly grass and cassava:

[0015] a. Check seedlings and replant: After cassava seedlings emerge, investigate the emergence of seedlings and replant the missing seedlings in time; when the cassava seedlings are 20-30cm tall, remove weak and diseased seedlings and leave 1-2 strong seedlings in each hole;

[0016] 7-10 days after planting the agarwood, check the survival status, remove dead seedlings in time, and replant seedlings of the same age;

[0017] b. Water management: In the early and middle stages of cassava growth, water should be applied in time in case of drought; after heavy rain, water should be removed from the field in time; during the growth of agar grass, the soil should be kept moist, water should be applied in case of drought, and water should be removed in time after rain;

[0018] c. Weeding: In the early stage of cassava growth, the seedlings are relatively short, so weeds in the holes and between the furrows are removed manually; in the middle and late stages of cassava growth, weeding is done manually or with herbicides, and climbing vines are cut off;

[0019] Before closing the row of agarwood, weeds in the holes and ditches of the agarwood should be removed manually; after closing the row, weeds should be removed promptly and the opening of the mulch film near the agarwood should be gradually enlarged;

[0020] d. Topdressing: For cassava, topdress appropriately according to the abundance and deficiency of soil nutrients and the growth of cassava; the first topdressing should be carried out 60 to 80 days after planting, with 5 to 7 kg of urea and 10 to 15 kg of compound fertilizer per mu of planting land; the second topdressing should be carried out 100 to 120 days after planting, with 10 to 15 kg of compound fertilizer and 10 to 15 kg of potash fertilizer per mu of planting land;

[0021] For agar grass, 10-15 days after planting, apply 2.5-3.0kg urea and 5-6kg ammonium carbonate per mu, add 1000kg water to dissolve and dilute before watering; apply topdressing once a month, and continue topdressing 2-3 times, each time using 10-20kg potassium sulfide compound fertilizer with N:P:K ratio of 15:15:15 per mu;

[0022] e. Disease and pest control: As a medicinal and edible plant, agarwood is usually not controlled by chemical agents. If diseased or insect-infested plants are found in the field, they should be promptly removed and taken out of the field for disposal. Cassava intercropping has fewer diseases and pests and usually does not require special control.

[0023] (6) Harvest the agarwood at the right time: harvest the agarwood all at once or in batches before buds appear;

[0024] (7) Autumn corn planting: After the agarwood is harvested, the mulch film is removed from the planting site, and autumn corn is planted in the agarwood planting belt without tillage;

[0025] Corn seed treatment: the seeds should be air-dried for 1-2 days before sowing to improve the germination and emergence rate of the seeds; to prevent and control underground insect pests, sterilize and disinfect the seeds one day before sowing.

[0026] Sowing density: According to the characteristics of the variety, the row spacing of densely planted varieties is 40-50cm, and the plant spacing is 20-25cm; the row spacing of conventional varieties is 50-60cm, and the plant spacing is 30cm;

[0027] Sowing: Sow 1 to 2 seeds per hole, the sowing depth is 3 to 5 cm.

[0028] (8) Corn field management: Check and replenish seedlings, and promptly check and replenish seedlings after emergence, and replenish missing seedlings in time to ensure that the emergence rate is above 90%;

[0029] Intertillage and weeding: When the corn seedlings have 5 pairs of true leaves, shallow hoeing is performed. When the seedlings are 50-70 cm tall, deep hoeing and soiling are performed. Intertillage and soiling are performed before the field is closed. The soiling should be solid to prevent lodging and yield reduction in the later stage.

[0030] Reasonable watering: Water corn in time when drought occurs during jointing to promote normal growth and development of corn. Water once when tassels emerge and bloom and combine fertilization, and water twice during the filling period to keep the soil moisture at 70-80% of the field water holding capacity.

[0031] Topdressing: The first topdressing fertilizer is applied within 10 days after jointing, 10-15 kg of urea per mu, and the distance between fertilizer and seedling is 5-7 cm; the second topdressing fertilizer is applied at the trumpet stage 10-15 days before corn tasseling, 20-25 kg of urea per mu;

[0032] Pest and disease control: According to the occurrence of corn pests and diseases, targeted pesticide spraying is carried out for prevention and control;

[0033] (9) Harvest cassava and corn at the right time: corn can be harvested when its husks are dry and loose and the kernels are hard and shiny; cassava can be harvested 6 to 12 months after planting, depending on the characteristics of the planted variety;

[0034] (10) Alternating intercropping: After harvesting cassava and corn, continue to rotate crops according to steps (1) to (9).

[0035] Furthermore, in the step (1), the cassava, agar grass or corn are intercropped in furrows; the intercropping ratio is 2:3, the furrow width is 0.9-1.0 m, cassava has 2 rows per furrow, and agar grass has 3 rows per furrow; the intercropping ratio is 2:4, the furrow width is 1.1-1.2 m, cassava has 2 rows per furrow, and agar grass has 4 rows per furrow; the length of each furrow should not exceed 30 m, the cassava row spacing is 60-70 cm, the plant spacing is 60-70 cm, the agar grass row spacing is 30-40 cm, and the plant spacing is 40-45 cm.

[0036] Furthermore, in the step (3), the cassava is planted flat or obliquely. The flat planting is to dig a hole or open a planting furrow on the ridge surface, and lay the seed stem flat in the planting hole or planting furrow, cover the soil to a depth of 5.0 to 8.0 cm, and the seed stem bud is in the same direction as the row direction; the oblique planting is to place the stem segment at an angle of 30° to 45° to the ridge surface, and insert the stem segment in an alternating and oblique manner on the ridge side toward the ridge center, with the bud eyes facing the outside of the ridge, and the exposed stem segment is ≤5 cm.

[0037] Furthermore, during the planting process in step (4), the ground film is made of black plastic film or silver-black two-color film; the planting hole depth of the agarwood grass is 8 to 10 cm and the diameter is 5 to 6 cm.

[0038] Furthermore, in step (5), topdressing is performed on a sunny day between 9:00 and 17:00 when there is no dew on the agar grass. The fertilizer is spread while being gently swept onto the soil with a soft branch or a broom. If there is no rain for several consecutive days after fertilization, watering is required in a timely manner.

[0039] Furthermore, in step (6), if all the leaves are harvested at once, the grass agarwood should be harvested in time when the leaves at the top of the branches are densely packed in a cross shape and the leaf edges turn slightly red; if the grass agarwood is harvested in batches, 70-80% of the aboveground parts should be harvested at intervals in mid-to-late July, and all the aboveground parts should be harvested in mid-October; the harvesting time should be selected on a sunny day after the dew has dried up, and the aboveground parts should be harvested and cut off 2-3 cm from the ground.

[0040] Furthermore, in the step (7), the corn planting is sterilized by adding 50 mL of 50% phoxim emulsifiable concentrate to 1.0 L of water, and then evenly diluting the mixture and spraying the mixture on the seeds, drying the mixture in the shade, and then sowing the seeds.

[0041] Furthermore, in step (8), during the process of checking and supplementing seedlings, the plots that are prone to compaction are lightly harrowed before the seedlings emerge to promote emergence.

[0042] Furthermore, in the step (8), pest control is carried out according to the occurrence of corn leaf spot, southern rust, brown leaf spot, borer pests, soybean rust, leaf spot, bean pod borer, soybean borer, and beet armyworm, and fungicides such as Bacillus subtilis, Jinggangmycin, pyrazole·fluoxetine, benzoyl·pyraclostrobin, propanedion·pyraclostrobin and insecticides containing chlorantraniliprole, high-efficiency chlorflucythrinate, deltamethrin, and thiamethoxam are selected for spraying and control.

[0043] The compound fertilizers used in the present invention are all nitrogen, phosphorus and potassium compound fertilizers (N-P2O5-K2O=15-15-15), and other fertilizers and related agents are all commercially available products.

[0044] The method of the present invention is that two years is an alternating intercropping cycle, and cassava, agar grass and corn are planted in turn in the same planting belt. Through alternating intercropping cultivation, inter-annual rotation is realized, which is conducive to alleviating soil continuous cropping obstacles, maintaining soil health, cultivating strong seedlings, enhancing the growth potential of cassava, and improving its disease and insect pest resistance; it is more conducive to protecting natural enemies, disrupting the life cycle of diseases and insect pests, and reducing their incidence, thereby reducing the occurrence of cinnabarinus spider mites, and realizing agricultural prevention and control of cinnabarinus spider mites in cassava fields.

[0045] Compared with the prior art, the present invention has the following beneficial effects:

[0046] 1. The present invention utilizes the space effect through the alternating intercropping of cassava and agarwood / corn, makes full use of light, temperature and heat, increases ventilation and light transmission performance, improves the microenvironment of farmland, and promotes the coordinated growth of crops; agarwood has a large water demand and needs watering for a long time, and can promote the early emergence, uniform and strong seedlings of cassava, enhance the growth potential of cassava, and improve its disease and insect pest resistance; the two crops have different fertilizer requirements, which can improve the utilization rate of fertilizer, and the alternating intercropping is also beneficial to alleviating soil continuous cropping obstacles, maintaining soil health, and avoiding the problems of weak crop growth potential, serious diseases and insect pests, and reduced yield caused by continuous cropping; at the same time, the alternating intercropping disrupts the life cycle of diseases and insect pests, reduces their incidence, is beneficial to protecting natural enemies, thereby reducing the occurrence of cinnabarinus spider mites, and realizing the agricultural prevention and control of cinnabarinus spider mites in cassava fields.

[0047] 2. The intercropping method of the present invention can reduce the planting risk of a single crop, increase farmers' income, and also improve land utilization, and stabilize the planting area of ​​cassava, jelly grass and corn. According to the survey, the mite damage index of cassava intercropped with jelly grass (corn) is reduced by 29.9-60.28% compared with the cassava land with single planting without chemical prevention of cinnabar spider mites, and is reduced by 16.78-26.78% compared with the cassava land with single planting chemical prevention of cinnabar spider mites, achieving the effect of control without pesticides. In the process from the onset of cassava cinnabar spider mites to the peak of occurrence, this planting pattern shows a good agricultural control effect. After research, it was found that alternating intercropping of cassava and jelly grass (corn) can reduce the occurrence of cinnabar spider mites and delay the time of occurrence. At the same time, certain economic benefits can be obtained after the jelly grass and corn are mature and harvested. Both jelly grass and corn are economic crops, and the income per mu can be increased by about 40-52% after harvest. The invention realizes agricultural control of cassava spider mites by alternately intercropping cassava and agar grass (corn), alleviates soil continuous cropping obstacles, maintains soil health, reduces control costs, alleviates environmental pollution, protects natural enemies, and increases economic benefits.

[0048] 3. The alternating intercropping mode of the present invention reduces the cost of controlling cassava spider mites, improves land utilization and planting income, and reduces environmental pollution. It has good ecological benefits, simple cultivation methods, and strong repeatability. It is easy to promote and apply on a large scale, boost the agar-agar grass industry, and ensure the planting area of ​​food crops such as cassava and corn. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 Flow chart of the alternating intercropping cultivation method for effective control of cassava spider mites.

[0050] Figure 2 This is a schematic diagram of intercropping cassava and corn in equal rows at a ratio of 2:3.

[0051] Figure 3 This is a schematic diagram of intercropping cassava and corn in equal rows of 2:4.

[0052] Figure 4 This is a schematic diagram of the field growth of early-stage cassava intercropped with mature seedlings of agar-agar grass and the damage of cassava to mites.

[0053] Figure 5 Schematic diagram of the field growth of cassava intercropped with corn seedlings in the middle stage of growth and the damage of cassava to mites.

[0054] Figure 6 Schematic diagram of the damage caused by spider mites when cassava is planted alone without chemical protection.

[0055] Figure 7 Schematic diagram of the damage of cassava monoculture to spider mites. DETAILED DESCRIPTION

[0056] The present invention is further described in detail below by way of examples. These examples are only used to illustrate the present invention and do not limit the protection scope of the present invention.

[0057] Example 1

[0058] An alternating intercropping cultivation method for effectively preventing and controlling cassava spider mites comprises the following steps:

[0059] (1) Intercropping row spacing planning: Cassava, agar grass or corn are intercropped in a 2:3-4 row ratio; intercropping is done in ridges; if the intercropping ratio is 2:3, the ridge width is 0.9-1.0 m, with 2 rows of cassava and 3 rows of agar grass per ridge; if the intercropping ratio is 2:4, the ridge width is 1.1-1.2 m, with 2 rows of cassava and 4 rows of agar grass per ridge; the length of each ridge should not exceed 30 m, with cassava row spacing of 60-70 cm, plant spacing of 60-70 cm, agar grass row spacing of 30-40 cm, and plant spacing of 40-45 cm.

[0060] (2) Site selection and land preparation: Select flat or gently sloping land with loose and deep soil, medium or above fertility, convenient irrigation and drainage, and suitable for continuous planting; plow the land, mix all the base fertilizers, evenly spread them on the surface, and plow them into the soil; harrow the soil and then make ridges according to the planting specifications. The ridge surface width is 90cm-110cm, the ridge bottom width is 130cm-150cm, the ridge height is 25cm-35cm, and the ridge bottom width is 40-50cm; every 667m 2 Apply 500kg-800kg of biological organic fertilizer or 1000kg-2000kg of decomposed farmyard manure, 40-50kg of phosphate fertilizer, and 30kg-40kg of compound fertilizer;

[0061] (3) Selection and planting of cassava seed stems: Planting should be carried out in March or April of the same year when the daily average temperature is ≥18℃; select fully mature and lignified main stems or primary branches as seed stems, with a seed stem length of 15cm to 20cm; then plant cassava according to the plant spacing specifications; cassava should be planted flat or obliquely. Flat planting means digging holes or planting trenches on the ridge surface, laying the seed stems flat in the planting holes or planting trenches, covering the soil to a depth of 5.0cm to 8.0cm, and the seed stem bud direction should be in the same direction as the row direction. Oblique planting means that the stem segment is 30° to 45° with the ridge surface, and is inserted obliquely from the side of the ridge toward the center of the ridge, with the bud eyes facing the outside of the ridge, and the exposed stem segment is ≤5cm.

[0062] (4) Cutting seedling cultivation and planting of agarwood:

[0063] a. Planting time: intercropping agar grass and cassava should be planted at the same time, or agar grass should be planted first and cassava should be planted 10-15 days later;

[0064] b. Cutting seedlings: In spring, when the temperature rises steadily to above 15°C, cutting seedlings can be carried out; first, level the field and place the seedling trays in rows for standby use; add 25 to 30 g of 50% wettable carbendazim powder to every 1000 kg of field topsoil, mix it with water to form a slurry, put it into the seedling tray, and flatten it; then, cut the strong, disease-free and insect-free tender stems from the wintering agarwood mother plant as cuttings, each cutting is 5 to 8 cm long, leaving 2 to 3 nodes and 1 pair of top leaves, soak the cuttings in 1000 times 50% wettable carbendazim powder for 3 to 5 minutes, and immediately carry out cuttings into the seedling tray after taking them out;

[0065] c. Management measures for cutting seedlings: When the temperature is ≤15℃, build an arch shed and cover it with white film for heat preservation; when the temperature is ≥25℃, cover it with a shade net with a shade degree of 40-50% to prevent sun exposure and cool down; 5-6 days before transplanting, remove the covering; water to maintain soil moisture at 60-70%; remove weeds in time to keep the seedbed clean; 15 days after cutting, irrigate once every 7 days with 0.1-0.2% urea solution;

[0066] d. Transplanting and planting: 20 to 30 days after cutting, when the cuttings are growing healthily, start transplanting; 1 day before transplanting, water the seedling tray thoroughly and lift the seedlings with soil; lay the ground film on the ridge surface, using black plastic film or silver-black two-color film; compact the surrounding area with soil; when planting, break the film and dig holes according to the spacing between plants and rows, with a planting hole depth of 8 to 10 cm and a diameter of 5 to 6 cm. Place the seedlings vertically into the hole, cover the hole with soil and compact it, and the seedlings should be exposed outside the ground film; after planting, water the soil enough to establish roots, and water it every day to keep the soil moist;

[0067] (5) Field management of jelly grass and cassava:

[0068] a. Check seedlings and replant: After cassava seedlings emerge, investigate the emergence of seedlings and replant the missing seedlings in time; when the cassava seedlings are 20-30cm tall, remove weak and diseased seedlings and leave 1-2 strong seedlings in each hole;

[0069] 7-10 days after planting the agarwood, check the survival status, remove dead seedlings in time, and replant seedlings of the same age;

[0070] b. Water management: In the early and middle stages of cassava growth, water should be applied promptly in case of drought; after heavy rain, water should be removed from the field in a timely manner;

[0071] During the growth period of the agar grass, the soil needs to be kept moist. In case of drought, water should be applied and drainage should be carried out in time after rain.

[0072] c. Weeding: In the early stage of cassava growth, the seedlings are relatively short, so weeds in the holes and between the furrows are removed manually; in the middle and late stages of cassava growth, weeding is done manually or with herbicides, and climbing vines are cut off;

[0073] Before closing the row of agarwood, weeds in the holes and ditches of the agarwood should be removed manually; after closing the row, weeds should be removed promptly and the opening of the mulch film near the agarwood should be gradually enlarged;

[0074] d. Topdressing: For cassava, topdress appropriately according to the abundance and deficiency of soil nutrients and the growth of cassava; the first topdressing should be carried out 60 to 80 days after planting, with 5 to 7 kg of urea and 10 to 15 kg of compound fertilizer per mu of planting land; the second topdressing should be carried out 100 to 120 days after planting, with 10 to 15 kg of compound fertilizer and 10 to 15 kg of potash fertilizer per mu of planting land;

[0075] For agar-agar grass, 10d to 15d after transplanting, apply 2.5-3.0kg of urea and 5-6kg of ammonium carbonate per mu, add 1000kg of water to dissolve and dilute, and then apply it; apply topdressing once a month thereafter, and topdress 2-3 times in a row, each time using 10-20kg of potassium sulfonyl compound fertilizer with a N:P:K ratio of 15:15:15 per mu; topdressing should be done on sunny days between 9:00 and 17:00, when there is no dew on the agar-agar grass. While spreading the fertilizer, use soft branches or a broom to gently sweep the fertilizer on the leaves into the soil. If there is no rain for several consecutive days after fertilization, water the grass in time.

[0076] e. Disease and pest control: As a medicinal and edible plant, agarwood is usually not controlled by chemical agents. If diseased or insect-infested plants are found in the field, they should be promptly removed and taken out of the field for disposal. Cassava intercropping has fewer diseases and pests and usually does not require special control.

[0077] (6) Timely harvesting of agarwood: Agarwood can be harvested all at once or in batches before buds appear. If harvested all at once, it should be harvested when the leaves at the top of the branches are densely packed in a cross shape and the leaf edges turn slightly red. If harvested in batches, it should be harvested in mid-to-late July, with 70-80% of the aboveground parts harvested at intervals, and all harvested in mid-October. The best time to harvest is on a sunny day, after the dew has dried up, and the aboveground parts should be harvested and cut 2-3 cm from the ground.

[0078] (7) Autumn corn planting: After the agarwood is harvested, the mulch film is removed from the planting site, and autumn corn is planted in the agarwood planting belt without tillage;

[0079] For corn seed treatment, the seeds should be aired for 1 to 2 days before sowing to increase the germination and emergence rate of the seeds. To prevent and control underground pests, sterilization should be carried out one day before sowing. For sterilization and disinfection, 50 mL of 50% phoxim emulsifiable concentrate is diluted with 1.0 L of water, and then evenly sprayed on the seeds. After drying in the shade, sow them.

[0080] Sowing density: According to the characteristics of the variety, the row spacing of densely planted varieties is 40-50cm, and the plant spacing is 20-25cm; the row spacing of conventional varieties is 50-60cm, and the plant spacing is 30cm;

[0081] Sowing: Sow 1 to 2 seeds per hole, the sowing depth is 3 to 5 cm.

[0082] (8) Corn field management: Check and supplement seedlings, and promptly check and supplement seedlings after emergence, and make up for the missing seedlings in time to ensure that the emergence rate is above 90%; for plots that are prone to compaction, lightly harrow before emergence to promote emergence.

[0083] Intertillage and weeding: When the corn seedlings have five pairs of true leaves, shallow hoeing is performed. When the seedlings are 50-70 cm tall, deep hoeing and soiling are performed. Intertillage and soiling are performed before the field is closed. The soiling should be solid to prevent lodging and yield reduction in the later stage.

[0084] Reasonable watering: Water corn in time when drought occurs during jointing to promote normal growth and development of corn. Water once when tassels emerge and bloom and combine fertilization, and water twice during the filling period to keep the soil moisture at 70-80% of the field water holding capacity.

[0085] Topdressing: The first topdressing fertilizer is applied within 10 days after jointing, 10-15 kg of urea per mu, and the distance between fertilizer and seedling is 5-7 cm; the second topdressing fertilizer is applied at the trumpet stage 10-15 days before corn tasseling, 20-25 kg of urea per mu;

[0086] Pest and disease control: According to the occurrence of corn diseases and pests, targeted pesticide spraying is carried out for prevention and control.

[0087] According to the occurrence of corn large and small leaf spot, southern rust, brown spot, boring pests, soybean rust, leaf spot, pod borer, soybean borer, and beet armyworm, fungicides such as Bacillus subtilis, jinggangmycin, pyrazole·fluepiconazole, benzo·myzoxystrobin, propaned·myzoxystrobin, and insecticides containing chlorantraniliprole, highly effective chlorflucythrinate, deltamethrin, and thiamethoxam are selected for spraying and prevention.

[0088] (9) Harvest cassava and corn at the right time: corn can be harvested when its husks are dry and loose and the kernels are hard and shiny; cassava can be harvested 6-12 months after planting, depending on the characteristics of the planted variety;

[0089] (10) Alternating intercropping: After harvesting cassava and corn, continue to rotate crops according to steps (1) to (9).

[0090] Experimental example

[0091] According to the above method, a field experiment will be set up at the cassava experimental base of Guangxi South Asian Tropical Agricultural Science Research Institute from 2022 to 2023, with a total of five treatments:

[0092] A. Cassava monoculture, no chemical agents are used to control spider mites: row spacing is 1.0m, plant spacing is 0.8m (CK1), such as Figure 6 shown.

[0093] B. For cassava monoculture, chemical agents are used to control cinnabar spider mites three times during the whole growth period, with a row spacing of 1.0m and a plant spacing of 0.8m (CK2). The first control is at the early stage of damage, when the mite plant rate reaches 20%, usually in early to mid-June; the second control is before the first peak of damage, usually in late June to early July; the third control is before the second peak of damage, usually in early September. The specific control time depends on the cassava mite damage situation of the year; the chemical agent is 1.8% avermectin emulsifiable concentrate 2000-3000 times liquid for leaf back spraying; Figure 7 shown.

[0094] C. Monocropping of agarwood: row spacing 0.3m, plant spacing 0.4m. Agarwood is a medicinal and edible plant, and no chemical control is required.

[0095] D. Cassava and agar grass (corn) are intercropped at a ratio of 2:3: adopt furrow cultivation, with a furrow width of 0.9m, cassava is planted in 2 rows per furrow, with a row spacing of 60cm and a plant spacing of 70cm; agar grass is planted in 3 rows per furrow, with a row spacing of 30cm and a plant spacing of 40cm; corn row spacing is 40cm and plant spacing is 30cm; Figure 4 , Figure 5 shown.

[0096] E. Intercropping of cassava and agar grass (corn) 2:4: adopt ridge cultivation, with a ridge width of 1.1m. Cassava is planted in 2 rows per ridge, with a row spacing of 60cm and a plant spacing of 70cm. Agar grass is planted in 4 rows per ridge, with a row spacing of 30cm and a plant spacing of 40cm. Corn has a row spacing of 30cm and a plant spacing of 40cm.

[0097] Each treatment was replicated 3 times in a randomized block design.

[0098] Among them, in 2022 (the first year of planting), conventional planting was carried out, cassava was planted on March 20, harvested on December 11, and the yield was measured, agar grass was planted on March 24, and the yield was measured on August 5; corn was planted on August 10 and harvested on December 10; the damage of cassava spider mites was investigated once in June, August, and mid-October, respectively, and the results are shown in Table 1. The economic benefits of planting were summarized, and the results are shown in Table 3.

[0099] In 2023, treatments D and E adopted an alternating intercropping method, that is, cassava was planted in the same ridge as cassava in the previous year, and cassava was planted in the same ridge as cassava in the previous year. The other three treatments remained unchanged, and the cultivation method was the same as the previous year. Cassava was planted on March 15, harvested on December 15, and the yield was measured. The cassava was planted on March 20 and the yield was measured on August 19; corn was planted on August 22 and harvested on December 20; the damage was investigated during the peak period of cassava spider mite damage (August 20), and the results are shown in Table 2. The economic benefits of planting were summarized, and the results are shown in Table 4.

[0100] Table 1 Comparison of damage to cinnabarinus spider mites in different treatments of cassava in 2022

[0101]

[0102] Note: (1) As the agarwood is less affected by Tetranychus cinnabarinus, no investigation on mite damage was conducted on agarwood monoculture.

[0103] (2) Calculation formula of mite index:

[0104] Where: I, represents the mite damage index; S, leaf damage level; N S , the number of leaves at this damage level; N, the total number of leaves investigated.

[0105] From Table 1 and Figures 4 to 7 It can be seen that: (1) Figures 4 to 7 By comparison, when cassava is intercropped with agar grass / corn, cassava is less susceptible to spider mites, and the entire field has almost no green-yellow leaves. Figure 6 When chemical agents are not used for control and cassava is grown as the only crop, the damage caused by mites is more serious, with a large number of cassava leaves losing their green color, turning yellow, drying up and falling off. Figure 7When cassava is planted alone and treated with chemical agents, the mite situation can be controlled to a certain extent, but it is still affected, so the leaves show a small amount of yellowing.

[0106] (2) From the comparison between Group A and Group B, it can be seen that in the case of cassava monoculture, the use of chemical agents for the control of spider mites can curb and reduce the mite damage to a certain extent, and the mite damage index can be reduced by 13.1-33.5%, especially in the peak period (August), the mite damage index can be reduced by 33.5%. This shows that chemical control has played an effective control role.

[0107] (3) Intercropping cassava with agar grass / corn can effectively prevent and control the disease of spider mites. From the comparison of groups B, D, and E, it can be seen that groups D and E do not use special chemical agents for prevention and control, but the mite damage index is compared with group B. The mite damage index has been reduced every time the three surveys throughout the year, with a reduction of 16.78-25.6% in group D and 19.2-26.78% in group E. This shows that the intercropping method of the present invention can effectively prevent and control the damage of spider mites, and at the same time reduce the use of chemical agents, achieving the effect of green and safe planting.

[0108] (4) From the comparison of groups A, D, and E, we can see that compared with group A, the mite damage index was reduced each time during the three surveys throughout the year, with group D reducing by 29.9-57.4% and group E reducing by 32.3-60.28%. It can be seen that both groups D and E achieved good control effects on spider mites, and the difference in mite damage index was not large. The difference in mite damage index between group D and group E was 0.41-2.88%.

[0109] Table 2 Comparison of damage to cinnabarinus spider mites in different treatments of cassava in 2023

[0110]

[0111] Note: Agarwood is less affected by Tetranychus cinnabarinus, so the mite damage investigation on Agarwood monoculture is not conducted.

[0112] From the comparison between Table 2 and Table 1, it can be seen that after alternating planting in 2023 and 2022, the same effect is achieved in the prevention and control of cinnabar spider mites.

[0113] (1) Comparison of cassava monoculture: The data of Group A and Group B show that the use of chemical agents to control Tetranychus cinnabarinus reduced the rate of damaged plants, the rate of leaf damage, and the mite damage index by 33.89%, 20.87%, and 17.33%, respectively. This indicates that chemical control can effectively reduce the damage of Tetranychus cinnabarinus to cassava leaves and rhizomes, and play an effective control role.

[0114] (2) Comparison of the control effect between cassava monoculture without chemical control and cassava intercropping with agar grass / corn. From the comparison of groups A, D, and E, it can be seen that compared with group A, the mite damage index of group D was reduced by 40.96%, and that of group E was reduced by 40.11%. Both groups D and E achieved good control effects on T. cinnabarinus, and the difference in mite damage index was not significant, with a difference of 0.85%.

[0115] (3) Comparison of the control effect of cassava monoculture chemical control and cassava intercropping with jelly grass / corn. The comparison of groups B, D, and E shows that although groups D and E were not subjected to special chemical control, the mite damage index was still effectively reduced compared with group B, with a reduction of 23.63% in group D and 22.77% in group E. This shows that the intercropping method of the present invention can effectively prevent and control the damage of spider mites and reduce the use of chemical agents.

[0116] Table 3 Comparison of planting benefits of different treatments in 2022

[0117]

[0118] Note: The purchase price of fresh cassava is 0.84 Yuan / kg, the purchase price of agar-agar grass hay is 11.00 Yuan / kg, and the purchase price of corn is 2.0 Yuan / kg.

[0119] From Table 3, we can see that although the per-acre yield of cassava monoculture and agar-agar monoculture is higher than that of intercropping, the total economic benefit and net income benefit of intercropping are higher than those of monoculture, indicating that intercropping has the purpose of significantly increasing income. The specific explanation is as follows:

[0120] (1) Comparison of economic benefits between 2:3 intercropping and monocropping. In terms of total economic benefits, 2:3 intercropping (group D) was 1233.47 yuan / mu higher than cassava monocropping without chemical fertilizer (group A); 719.25 yuan / mu higher than cassava monocropping with chemical control of spider mites (group B); and 635.59 yuan / mu higher than agar-agar monocropping (group C). In terms of net income, 2:3 intercropping was 838.47 yuan / mu higher than cassava monocropping without chemical fertilizer (group A), an increase of 47.90%; 744.25 yuan / mu higher than cassava monocropping with chemical control of spider mites (group B), an increase of 40.35%; and 430.59 yuan / mu higher than agar-agar monocropping (group C), an increase of 19.95%.

[0121] (2) Comparison of economic benefits between 2:4 intercropping and monocropping. In terms of total economic benefits, 2:4 intercropping (group D) was 1302.39 yuan / mu higher than cassava monocropping without chemical fertilizer (group A); 788.17 yuan / mu higher than cassava monocropping with chemical control of spider mites (group B); and 704.51 yuan / mu higher than agar-agar monocropping (group C). In terms of net income, 2:4 intercropping was 907.39 yuan / mu higher than cassava monocropping without chemical fertilizer (group A), an increase of 51.84%; 813.17 yuan / mu higher than cassava monocropping with chemical control of spider mites (group B), an increase of 44.08%; and 499.51 yuan / mu higher than agar-agar monocropping (group C), an increase of 23.14%.

[0122] (3) In terms of intercropping at different ratios, there was no significant difference in economic benefits between Group D and Group E, and Group E had a slightly higher income than Group D. In terms of total economic benefits and net income, Group E had an increase of 68.92 yuan / mu compared to Group D.

[0123] Table 4 Comparison of planting benefits of different treatments in 2023

[0124]

[0125] Note: The purchase price of fresh cassava is 0.84 Yuan / kg, the purchase price of agar-agar grass hay is 11.00 Yuan / kg, and the purchase price of corn is 2.0 Yuan / kg.

[0126] From the comparison between Table 4 and Table 3, it can be seen that after alternating planting in 2023 and 2022, the difference between intercropping and monocropping is the same. In terms of per-acre yield, cassava monocropping and agar-agar monocropping are higher than intercropping, but in terms of total economic benefits and net yield benefits, intercropping mode is higher than monocropping. The specific explanation is as follows:

[0127] (1) Comparison of economic benefits between 2:3 intercropping and monocropping. In terms of total economic benefits, 2:3 intercropping (group D) was 1451.56 yuan / mu higher than cassava monocropping without chemical fertilizer (group A); 897.74 yuan / mu higher than cassava monocropping with chemical control of spider mites (group B); and 693.58 yuan / mu higher than agar-agar monocropping (group C). In terms of net income, 2:3 intercropping was 1056.56 yuan / mu higher than cassava monocropping without chemical fertilizer (group A), an increase of 48.41%; 922.74 yuan / mu higher than cassava monocropping with chemical control of spider mites (group B), an increase of 39.84%; and 488.58 yuan / mu higher than agar-agar monocropping (group C), an increase of 17.76%.

[0128] (2) Comparison of economic benefits between 2:4 intercropping and monocropping. In terms of total economic benefits, 2:4 intercropping (group D) was 1560.53 yuan / mu higher than cassava monocropping without chemical fertilizer (group A); 1006.71 yuan / mu higher than cassava monocropping with chemical control of spider mites (group B); and 802.55 yuan / mu higher than agar-agar monocropping (group C). In terms of net income, 2:4 intercropping was 1165.53 yuan / mu higher than cassava monocropping without chemical fertilizer (group A), an increase of 53.40%; 1031.71 yuan / mu higher than cassava monocropping with chemical control of spider mites (group B), an increase of 44.54%; and 597.55 yuan / mu higher than agar-agar monocropping (group C), an increase of 21.73%.

[0129] (3) In terms of intercropping at different ratios, there was no significant difference in economic benefits between Group D and Group E, and Group E had a slightly higher income than Group D. In terms of total economic benefits and net income, Group E had an increase of 108.97 yuan / mu compared to Group D.

[0130] In general, the present invention adopts an alternating intercropping cultivation mode, which can effectively prevent and control the damage of cassava spider mites, reduce the mite damage rate, and promote increased production and income.

[0131] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An alternating intercropping cultivation method for effectively preventing and controlling cassava spider mites, characterized in that: The following steps are involved: (1) Intercropping spacing planning: intercrop cassava, agar grass or corn in a 2:3-4 row ratio; (2) Site selection and land preparation: Select flat or gently sloping land with loose and deep soil, medium or above fertility, convenient irrigation and drainage, and suitable for continuous planting; plow the land, mix all the base fertilizers, evenly spread them on the surface, and plow them into the soil; harrow the soil and then make ridges according to the planting specifications, with a ridge surface width of 90-110 cm, a ridge bottom width of 130-150 cm, a ridge height of 25-35 cm, and a ridge bottom width of 40-50 cm; every 667 m 2 Apply 500-800kg of biological organic fertilizer or 1000-2000kg of decomposed farmyard manure, 40-50kg of phosphate fertilizer, and 30-40kg of compound fertilizer; (3) Selection and planting of cassava seed stems: Planting should be carried out in March or April of the same year when the daily average temperature is ≥18°C; fully mature and lignified main stems or primary branches should be selected as seed stems, with a length of 15 to 20 cm; and cassava should be planted according to the row spacing specifications; (4) Cutting seedling cultivation and planting of agarwood: a. Planting time: intercropping agar grass and cassava should be planted at the same time, or agar grass should be planted first and then cassava should be planted 10 to 15 days later; b. Cutting seedlings: In spring, when the temperature rises steadily to above 15°C, cutting seedlings can be carried out; first, level the field and place the seedling trays in rows for standby use; add 25 to 30 g of 50% wettable carbendazim powder to every 1000 kg of field topsoil, mix it with water to form a slurry, put it into the seedling tray, and flatten it; then, cut the strong, disease-free and insect-free tender stems from the wintering agarwood mother plant as cuttings, each cutting is 5 to 8 cm long, leaving 2 to 3 nodes and 1 pair of top leaves, soak the cuttings in 1000 times 50% wettable carbendazim powder for 3 to 5 minutes, and immediately carry out cuttings into the seedling tray after taking them out; c. Management measures for cutting seedlings: When the temperature is ≤15℃, build an arch shed and cover it with white film for heat preservation; When the temperature is ≥25℃, cover with a shade net with a shade degree of 40-50% to prevent sun exposure and reduce temperature; 5-6 days before transplanting, remove the covering; water to maintain soil moisture at 60-70%; remove weeds in time to keep the seedbed clean; 15 days after cutting, irrigate with 0.1-0.2% urea solution once every 7 days; d. Transplanting and planting: 20-30 days after cutting, when the cuttings are growing healthily, transplanting can be carried out; 1 day before transplanting, water the seedling tray thoroughly and lift the seedlings with soil; spread the ground film on the ridge surface and compact it with soil around; when planting, break the film and dig holes according to the spacing between plants and rows, put the seedlings vertically into the holes, cover the holes with soil and compact it, and the seedlings should be exposed outside the ground film; after planting, water the soil enough to allow the roots to take root, and water it every day to keep the soil moist; (5) Field management of jelly grass and cassava: a. Check seedlings and replant: After cassava seedlings emerge, investigate the emergence of seedlings and replant the missing seedlings in time; when the cassava seedlings are 20-30cm tall, remove weak and diseased seedlings and leave 1-2 strong seedlings in each hole; 7-10 days after planting the agarwood, check the survival status, remove dead seedlings in time, and replant seedlings of the same age; b. Water management: In the early and middle stages of cassava growth, water should be applied promptly in case of drought; after heavy rain, water should be removed from the field in a timely manner; During the growth period of the agar grass, the soil needs to be kept moist. In case of drought, water should be applied and drainage should be carried out in time after rain. c. Weeding: In the early stage of cassava growth, the seedlings are relatively short, so weeds in the holes and between the furrows are removed manually; in the middle and late stages of cassava growth, weeding is done manually or with herbicides, and climbing vines are cut off; Before closing the row of agarwood, weeds in the holes and ditches of the agarwood should be removed manually; after closing the row, weeds should be removed promptly and the opening of the mulch film near the agarwood should be gradually enlarged; d. Topdressing: For cassava, topdress appropriately according to the abundance and deficiency of soil nutrients and the growth of cassava; the first topdressing should be carried out 60 to 80 days after planting, with 5 to 7 kg of urea and 10 to 15 kg of compound fertilizer per mu of planting land; the second topdressing should be carried out 100 to 120 days after planting, with 10 to 15 kg of compound fertilizer and 10 to 15 kg of potash fertilizer per mu of planting land; For agar grass, 10-15 days after planting, apply 2.5-3.0kg urea and 5-6kg ammonium carbonate per mu, add 1000kg water to dissolve and dilute before watering; apply topdressing once a month, and continue topdressing 2-3 times, each time using 10-20kg potassium sulfide compound fertilizer with N:P:K ratio of 15:15:15 per mu; e. Disease and pest control: As a medicinal and edible plant, agarwood is usually not controlled by chemical agents. If diseased or insect-infested plants are found in the field, they should be promptly removed and taken out of the field for disposal. Cassava intercropping has fewer diseases and pests and usually does not require special control. (6) Harvest the agarwood at the right time: harvest the agarwood all at once or in batches before buds appear; (7) Autumn corn planting: After the agarwood is harvested, the mulch film is removed from the planting site, and autumn corn is planted in the agarwood planting belt without tillage; Corn seed treatment: the seeds should be air-dried for 1-2 days before sowing to improve the germination and emergence rate of the seeds; to prevent and control underground insect pests, sterilize and disinfect the seeds one day before sowing. Sowing density: According to the characteristics of the variety, the row spacing of densely planted varieties is 40-50cm, and the plant spacing is 20-25cm; the row spacing of conventional varieties is 50-60cm, and the plant spacing is 30cm; Sowing: Sow 1 to 2 seeds per hole, sowing depth is 3 to 5 cm; (8) Corn field management: Check and replenish seedlings, and promptly check and replenish seedlings after emergence, and replenish missing seedlings in time to ensure that the emergence rate is above 90%; Intertillage and weeding: When the corn seedlings have 5 pairs of true leaves, shallow hoeing is performed. When the seedlings are 50-70 cm tall, deep hoeing and soiling are performed. Intertillage and soiling are performed before the field is closed. The soiling should be solid to prevent lodging and yield reduction in the later stage. Reasonable watering: Water corn in time when it is dry during jointing to promote normal growth and development of corn. Water once during tasseling and flowering combined with fertilization, and water twice during the grain filling period to keep the soil moisture at 70-80% of the field water holding capacity. Topdressing: The first topdressing fertilizer is applied within 10 days after jointing, 10-15 kg of urea per mu, and the distance between fertilizer and seedling is 5-7 cm; the second topdressing fertilizer is applied at the trumpet stage 10-15 days before corn tasseling, 20-25 kg of urea per mu; Pest and disease control: According to the occurrence of corn pests and diseases, targeted pesticide spraying is carried out for prevention and control; (9) Harvest cassava and corn at the right time: corn can be harvested when its husks are dry and loose and the kernels are hard and shiny; cassava can be harvested 6 to 12 months after planting, depending on the characteristics of the planted variety; (10) Alternating intercropping: After harvesting cassava and corn, continue to alternately plant them according to steps (1) to (9).

2. The alternating intercropping cultivation method for effectively preventing and controlling cassava spider mites according to claim 1, characterized in that: In the step (1), the cassava, agar grass or corn are intercropped in furrows; the intercropping ratio is 2:3, the furrow width is 0.9-1.0 m, cassava has 2 rows per furrow, and agar grass has 3 rows per furrow; the intercropping ratio is 2:4, the furrow width is 1.1-1.2 m, cassava has 2 rows per furrow, and agar grass has 4 rows per furrow; the length of each furrow should not exceed 30 m, the cassava row spacing is 60-70 cm, the plant spacing is 60-70 cm, the agar grass row spacing is 30-40 cm, and the plant spacing is 40-45 cm.

3. The alternating intercropping cultivation method for effectively preventing and controlling cassava spider mites according to claim 1, characterized in that: In the step (3), cassava is planted flat or obliquely. Flat planting is to dig holes or planting trenches on the ridge surface, lay the seed stems flat in the planting holes or planting trenches, cover the soil to a depth of 5.0 to 8.0 cm, and the seed stem buds are in the same direction as the row direction; oblique planting is to place the stem segments at an angle of 30° to 45° to the ridge surface, and insert them in an alternating and oblique manner on the ridge side toward the ridge center, with the buds facing the outside of the ridge, and the exposed stem segments are ≤5 cm.

4. The alternating intercropping cultivation method for effectively preventing and controlling cassava spider mites according to claim 3 is characterized in that: During the planting process in step (4), the ground film is made of black plastic film or silver-black two-color film; the planting hole of the agarwood grass has a depth of 8 to 10 cm and a diameter of 5 to 6 cm.

5. The alternating intercropping cultivation method for effectively preventing and controlling cassava spider mites according to claim 1, characterized in that: In the step (5), topdressing is carried out on a sunny day between 9:00 and 17:00 when there is no dew on the agar grass. The fertilizer is spread while the fertilizer on the leaves is gently swept into the soil with a soft branch or a broom. If there is no rain for several consecutive days after fertilization, watering is required in a timely manner.

6. The alternating intercropping cultivation method for effectively preventing and controlling cassava spider mites according to claim 1, characterized in that: In the step (6), if all the leaves are harvested at once, they should be harvested in time when they are densely packed in a cross shape at the top of the branches and the leaf edges turn slightly red; if they are harvested in batches, 70-80% of the aboveground parts should be harvested at intervals in mid-to-late July, and all of them should be harvested in mid-October; the harvesting time should be selected on a sunny day after the dew has dried up, and the aboveground parts should be harvested and cut off 2-3 cm from the ground.

7. The alternating intercropping cultivation method for effectively preventing and controlling cassava spider mites according to claim 1, characterized in that: In the step (7), the corn planting is sterilized by adding 50 mL of 50% phoxim emulsifiable concentrate to 1.0 L of water, mixing and diluting, spraying evenly on the seeds, and sowing after drying in the shade.

8. The alternating intercropping cultivation method for effectively preventing and controlling cassava spider mites according to claim 1, characterized in that: In the step (8), during the process of checking and supplementing seedlings, the plots that are prone to compaction are lightly harrowed before the seedlings emerge to promote emergence.

9. The alternating intercropping cultivation method for effectively preventing and controlling cassava spider mites according to claim 1, characterized in that: In the step (8), pest control is carried out according to the occurrence of corn leaf spot, southern rust, brown leaf spot, borer pests, soybean rust, leaf spot, bean pod borer, soybean borer and beet armyworm, and fungicides such as Bacillus subtilis, Jinggangmycin, pyrazole·fluoxetine, benzoyl·pyraclostrobin, propanedion·pyraclostrobin and insecticides containing chlorantraniliprole, high-efficiency chlorflucythrinate, deltamethrin and thiamethoxam are selected for spraying and control.

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