Cultivation techniques of Hami melon ⅰ. Biological characteristics
Melons like hot, dry and sunny weather. The breeding period is 28 ~ 30℃ in the daytime, 16 ~ 20℃ at night, the ground temperature is 20 ~ 25℃, and the lower limit of underground 15 cm is above 18℃. In the growing period, if the sunshine is insufficient and the temperature is high, the stems and vines are easy to grow white, the female flowers are not easy to differentiate, and it is not easy to set fruit or bear bad fruit. If the temperature is too high at night, the temperature difference between day and night is small, the fruit is large, but the fruit surface is not perfect, the sugar content is reduced, and the quality is slightly worse. When the temperature is too low at night, the fruit expansion is blocked and the fruit setting rate is affected. Therefore, according to different cultivation periods, select suitable varieties.
Melon is a shallow-rooted crop with good soil permeability. If the cultivated soil is too shallow and the root system has poor extensibility, it will affect the seed setting rate. Therefore, it is ideal to choose soil with good air permeability, strong water retention and good ventilation. Acid neutrality is preferred, and it is suitable for rotation planting with rice and corn.
Second, cultivation and management.
(1) cultivation method:
1. Cultivation with silver and dark black plastic film cloth in the open field: This method can reduce the occurrence of virus diseases, maintain good soil physical properties, reduce the loss of water and nutrients, promote the development of root groups and many other advantages, and make the cultivation of cantaloupe more stable.
2. Tunnel greenhouse cultivation: it has the functions of preventing cold, keeping warm, preventing rain, reducing diseases and adjusting production cycle. Adjust the temperature and humidity in the border and shed.
3. Double cropping cultivation in greenhouse: In order to save cost, reduce labor force and shorten cultivation time, double cropping cultivation is adopted. Using the original cultivation bed and original facilities, materials and equipment, only change the planting position and replant cantaloupe. Those with good drainage, strong fertilizer conservation and long rotation years should be selected, and continuous cropping should be avoided in unsuitable soil. Strong disease resistance or early and stable growth, suitable for continuous cropping varieties.
4. Simple plastic film cloth room cultivation: This cultivation method has a long history, but the cultivation area is not enough because of the slightly higher funds. Simple plastic film cloth room cultivation can be divided into vertical cultivation and creeping cultivation. Vertical cultivation requires more labor and more accurate cultivation techniques. Without vertical cultivation experience, the yield is often unstable or poor. Creeping cultivation is extensive and stable, but the number of plants planted will be small, so it is advisable to consider it in detail before cultivation.
(2) Fertilizer and fertilization:
Cucumber is a short-term crop and quick-acting fertilizer is better. The determination of fertilization amount must consider the difference of soil fertility, soil properties, cultivation period and cultivated varieties, and the fertilization amount is also different. Excessive application is not only a waste, but also affects plant growth and causes physiological obstacles, insufficient fertilizer, weak plants and low yield. Fertilization methods include deep ploughing, comprehensive fertilization and furrow application. For the soil with deep soil layer, strong fertility and few times of water injection, it is best to plough deeply and spread enough fertilizer in the soil layer as the base fertilizer, and topdressing is supplemented by spraying liquid fertilizer on the leaves. In sandy land with shallow plough layer or poor fertility, nutrients are easy to be lost and water demand is large. The most suitable fertilization method is to apply 70% as base fertilizer in the ditch, 30% as topdressing for a few times, or install a spray hose with nutrient solution for fertilization. The suitable period of fertilization is divided into several periods. In different periods, the fertilizers and nutrients required by cantaloupe are also different.
Planting density: adjust the spacing between planting rows and plants according to the cultivation method, cultivation period, vine pulling method, soil properties and variety characteristics. In principle, the distance between two plants is about 50 cm.
(3) Pruning method: In order to make cantaloupe bear fruit in the most ideal position and make the fruit-bearing period consistent, pruning by coring is a necessary means of cultivation. The number of fruits left is the key to stable quality. Whether the operation period is appropriate and whether the branches are skilled directly affects the yield and quality, so this work can not be ignored in cultivation. Picking and pruning should be carried out in sunny days, spraying should be coordinated, and spraying should be avoided as far as possible during flowering, otherwise it should be carried out in the evening.
(4) Fruit guarantee: it is everyone's wish to increase the output per unit area. But when 1 cantaloupe has too many fruits, its commodity value will be greatly reduced. It is said that there are many fruits, but no good ones. Quality and quantity cannot be guaranteed, and the principle is quality first, output second, and fruit retention is more important. 5 ~ 10 days after the plant bears fruit, when the young fruit is as big as an egg, choose the long and straight fruit type to bear fruit. By the way, remove the petals of flower marks to reduce the invasion of germs. The number of fruits left should be determined according to the characteristics of varieties and the growth of plants.
Only when the appearance is excellent can the quality be stable. Therefore, in the concept of fruit protection of cantaloupe, elitism should be adopted, and the number of fruits should be less than greed. The fruiting period should not be too late, so as not to affect fertility. When cultivated in early spring, the fruit left on the vine with predetermined fruit will not swell well if it is exposed to continuous low temperature, and it can bear fruit for the second time when the plant grows stronger. If the number of fruits left for the first time is small, 1 fruit can be left per vine, but early-maturing varieties are suitable. The sugar content of the seeds grown in the later stage is slightly poor, and it is not ideal to keep the fruit again. It is more suitable to keep single vine than double vine in autumn, because there are large fruits and few fruits in autumn, and the principle of per plant 1 fruit is adopted. In order to reduce the occurrence of secondary fruit, when pruning, the female flowers of unfruitful vines should be removed immediately to avoid re-fruiting. In principle, there are fewer fruits left in autumn than in spring.
(5) Water control: Pumpkin is neither dry nor wet, and the amount of water injected depends on the development stage of pumpkin, soil properties, soil moisture and weather. It is advisable to keep proper moisture in the soil from the early stage of reproduction to before flowering, so that plants can develop robustly and slowly. When there is too much water, the stems and leaves are vigorous, which affects flowering and fruiting and is easy to get sick. Too dry will hinder fertility and poor growth. Water injection should be reduced during flowering and seed setting to avoid excessive growth and affect seed setting rate. 7 ~ 20 days after fruiting is the fastest period of fruit hypertrophy, which needs water urgently and needs more water injection. In particular, the soil with poor water retention capacity should be fully watered to promote fruit hypertrophy.
When the fruit is close to maturity, it is ideal to control the moisture and keep it dry properly. At this time, if the soil moisture is too much, the sugar is reduced, the ripening is delayed, the fruit is easy to crack and diseases occur. Non-reticular varieties are prone to sparse reticulation on the fruit surface, while white varieties are prone to uneven skin color or fruit. * * Holmium Ⅲ? What's the matter with you? After 4 ~ 20 days, the fruit surface began to form a network. If there is too much water in the early stage of reticulate formation, coarse cracks are easy to appear and reticulate is not beautiful. Therefore, it is advisable to reduce the water content about 7 days before the formation of the reticulation, and then gradually increase the water content when the reticulation is gradually completed, so as to promote the fruit expansion and improve the reticulation. If the soil is too dry, the reticulation on the fruit surface is fine and incomplete, and the appearance is not beautiful. When injecting water, try to keep the roots dry. When it rains, drain the accumulated water in the side ditch as soon as possible, and no accumulated water is allowed.
(6) Methods to promote fruit hanging: When the weather is clear, before fruit hanging, it is necessary to do a thorough job of leading vines and pruning, keep proper vine spacing, and have sufficient light and good ventilation. First, pick the vines and choose excellent female flowers to make them bear fruit. Under these conditions, the results are quite stable in most cases. In case of bad weather or indoor cultivation, if there are no vector insects, artificial pollination should be carried out, and bisexual flowers should be lightly pollinated on their stigmas with watercolor pens on the day of flowering to promote fruit. Spring seeds often encounter cold current, temperature drop, poor flowering, weak pollen vitality and low fruit setting rate, so fruit promoters should be used to improve fruits. Under the condition of quality first, natural fruiting (insect-borne or artificial pollination) is the most ideal way of fruiting.
(7) Fruit bagging and fruit hanging: In order to make the fruit clean and beautiful, the peel color is completely uniform, and reduce fruit diseases and insect pests, avoid direct contact with pesticides when spraying chemical agents, and it is best to bag and hang the fruit after the fruit is produced. Vertical cultivation, after the fruit is left, the fruit stalk should be hung with a string and fixed on the horizontal line of the column to prevent the vines from breaking and the fruit from falling off.
Third, harvesting and packaging.
(1) Determine the appropriate harvest period.
The sugar content of Hami melon increased rapidly before and after the fruit approached maturity. If harvested too early, not only the sugar content is low, but also the meat quality is not good. Too late harvest affects the storage and transportation capacity, so the best harvest time should be when the fruit sugar has reached the highest point and the quality is not soft. Early-maturing varieties are generally easy to stalk and have poor storage and transportation, so they should be harvested before stalk removal. Late-maturing varieties should not be too early, otherwise the sugar will not reach the standard. In most cases, the suitable harvest time of melon varieties can be comprehensively judged by the following methods.
1. Peel discoloration: When the fruit is ripe, the varieties with discolored peel are easy to turn into yellow, orange, yellow-green, milky white, etc. According to the discoloration of the peel, the suitable harvest time can be judged.
2. Marks around the fruit pedicel: When the fruit pedicel and the fruiting part begin to show signs of cracks, harvest them before the pedicel is separated.
3. The fruit stalks or pedicels are yellow: most varieties without reticular lines have this characteristic when harvested at low temperature.
4. Results The symptoms of old leaves on vine were similar to those of yellow magnesium deficiency.
5. Calculate the expiration days: use this as a sign to judge the expiration period.
6. Harvest and taste: firstly, 2-3 fruits are harvested and tasted, and at the same time, the sugar content and quality are investigated to determine the appropriate harvest time.
(2) harvest.
It is advisable to harvest when the temperature is low in the morning. After harvesting, fruits should be kept in a cool place to avoid overlapping. After the temperature and respiration of fruits decrease, they should be packed and boxed in stages. In most cases, cantaloupe has the function of post-ripening, and the quality is the best in 2 ~ 3 days at room temperature after harvesting, which is a suitable edible period. The longer the melon is stored, the lower the sugar content.
Four, pests and diseases and their prevention and control
(1) Fusarium wilt.
The leaves appear pale yellow or even dark brown concentric wheel-shaped depression, which causes cracks for a short time. Stems are soaked first, and always secrete reddish-brown fat, and finally become gray-brown cork-like dry spots with small spots (capsule shells). Disease spots often occur at the root head or stem node, and the root head often expands to make the whole plant wither and die (commonly known as head failure).
Control method: spraying mankuning 800 times solution. Once every 5 ~ 7 days, 4 ~ 5 times in a row.
Apply 10 times water of Wankunning or 53.8% copper hydroxide to the diseased part of stem every 5? Once every seven days.
(2) Downy mildew.
Most of them start from the old leaves at the base, and at first they are inconspicuous pale yellow spots, and then they are polygonal yellow-brown obvious lesions bounded by veins, which are dry and easy to break; The diseased spots on the back of the leaves are dark and black, and the leaves die early.
Prevention and control: 1, spray the green essence solution 400 times, 7 days 1 time, and 3 ~ 4 days 1 time at onset.
2, ray Domil spray 500 ~ 800 times.
(3) Bacterial spot disease.
At first, the leaves were neither plastic nor angular, and soon became grayish brown, and the tissues were broken into small holes.
Control method: 10% kuikuning powder 1000 ~ 1500 times liquid is sprayed on the leaves every 7 ~ 10 day 1 time.
(4) powdery mildew.
Stems and leaves (especially the back of leaves) produce white powder, then turn gray, appear small black particles, and leaves turn yellow.
Prevention and control methods: Powder rust is sprayed with 3000 times solution once every 7 days, once every 4-5 days, and continuously for 3-4 times.
(5) whitefly.
Hazard: In addition to direct plant nutrient solution for adults and larvae, it also spreads virus diseases. Adults and larvae secrete honey dew, which induces ants or other insects to do great harm, induces black coal disease and affects photosynthesis.
Key points of seasonal cultivation techniques and variety selection of Hami melon (1)
Because cantaloupe is resistant to high temperature but not cold, it can only be cultivated in fully enclosed automatic greenhouse without seasonal restrictions. In the absence of heating or good insulation facilities, such as glass or plastic greenhouse, the season with less rainfall, good sunshine and large temperature difference should be chosen. Jianghuai Plain, Shanghai, Zhejiang and other places should mature before the rainy season. Guangdong and other places choose autumn with less rainfall, and Hainan and other places choose dry season. Soilless culture is characterized by large investment and high cost, so it is best to choose excellent varieties with strong disease resistance, reticulation, good quality, unique appearance and flavor.
(2) Planting method
Soilless culture can be divided into hydroponics and substrate culture. Hydroponics is to float the roots of pumpkin in nutrient solution, or apply nutrient solution to the roots. Substrate cultivation is to cultivate pumpkin in solid substrate, add nutrient solution, or add enough organic fertilizer into the substrate, and then apply organic fertilizer as needed in the middle growth stage. Just drop water, not nutrient solution during the whole growth period. The better method of watermelon hydroponics is the deep-water cultivation method adopted by Zhuhai and Dongguan Agricultural Institute in Guangdong Province. The melons grown by this method are big and uniform in shape, but the nutrient solution management is strict and the technical requirements are high. There are two kinds of substrate cultivation of Hami melon: substrate plus nutrient solution cultivation method and organic substrate cultivation method. Substrate cultivation management is convenient, but the single melon is small and the fruit shape is not symmetrical enough. Organic substrate cultivation is simple and low cost, but it is difficult to understand and control the nutritional status in the substrate, and it is easy to appear the phenomenon of unbalanced nutrient supply.
Deep water aquaculture technology has the characteristics of deep, flowing and hanging. Depth refers to the depth of the planting pot filled with nutrient solution, and the other is that the liquid layer of nutrient solution is relatively deep, so that the roots of plants can penetrate into the deeper nutrient solution. The total amount of nutrient solution in the whole planting system is large, and the composition, concentration, pH, moisture and temperature of nutrient solution are not easy to change sharply during plant growth. The growth environment of root system is relatively stable, and nutrition supplement and adjustment are convenient. Flow is the circulation of nutrient solution, which can increase the concentration of oxygen and reduce the harmful metabolites secreted by roots. Suspension means that plants are hung and planted above the liquid level of nutrient solution, so that the roots and necks of plants are far away from the liquid level, some roots grow deep into the liquid level of nutrient solution, and some roots are exposed to the humid air between the liquid level of nutrient solution and the planting plate, which is beneficial for the roots to absorb oxygen.
There are many kinds of deep-water aquaculture facilities, among which cement brick structure is widely used in China. The facility consists of four parts: planting tank, planting plate, liquid storage tank and nutrient solution circulating flow system. Generally, the width of the planting trough is 100 ~ 150 cm, the depth in the trough is controlled at about 12 ~ 15 cm, and the trough length is10 ~ 20 m. The nutrient solution can be directly placed in the planting trough. The planting board is made of high-density and hard white polystyrene board (commonly known as foam plastic board) with a thickness of 2 ~ 3 cm. Planting cups are drilled on the planting plate, and a planting cup is placed in each planting hole. The liquid storage tank is generally built underground, and the nutrient solution in the underground liquid storage tank is pumped into the planting tank by the water pump. Once the nutrient solution in the tank reaches the preset water level, it will flow into the liquid storage tank from the return pipeline under the action of gravity, and so on. The nutrient solution circulation system consists of a liquid supply pipeline, a water pump and a throttle valve.
There are many nutrient solution formulas for melon cultivation, Yamazaki formula and South China Agricultural University formula are both suitable for melon cultivation. However, the demand for nutrients in different growth stages of Hami melon is different. Generally, 0.5 dose is used at seedling stage, 1 dose at early flowering stage, and 1.2 dose can be used at late fruit development stage, and it should be increased or decreased according to the temperature, with the concentration increasing at low temperature and decreasing at high temperature. The nutrient solution management of deep-water living water culture method is that the nutrient solution circulates every day 14 hours to increase oxygen. The depth of nutrient solution is 7 ~ 10 cm, and each melon occupies 24 liters of nutrient solution. The cylinder surface should be sealed, otherwise it will cause moss growth and compete for nutrients. Measure the conductivity of nutrient solution every 5 ~ 7 days, add new fertilizer to keep the conductivity between 2 ~ 2.2, and add fresh water to the liquid storage tank every day according to evaporation and absorption to keep the original water level in the tank. In the whole production process, from the cleaning, disinfection, sowing, planting and harvesting of facilities, all links must be carried out by people, and at the same time, perfect management files should be established in order to achieve a scientific management system.
Because the nutrient solution is not recycled, except a small amount of nutrient solution added to the substrate can not be absorbed and utilized by plants, the rest is accumulated in the substrate, so the addition and supplement of nutrient solution depends on the weather, the water retention capacity of the substrate and the growth of plants. Compared with hydroponics, the solid substrate has stable performance, simple equipment and easy management. There are many kinds of substrates for substrate cultivation, usually there are two kinds: one is organic substrate, such as peat, sawdust, carbonized rice husk, bagasse, coconut bran and so on. The other is inorganic matrix, such as sand, vermiculite, rock wool, perlite, slag, foam plastic and so on. In production, in order to overcome the ventilation of a single substrate; Due to insufficient water retention, several substrates are often mixed and used, which is called mixed substrate. Such as peat with perlite, coconut bran with perlite, sawdust with mushroom residue, etc. Matrix culture can be carried out in large-scale culture tanks or bags. The nutrient solution can be dripped regularly and quantitatively, and any formula can be selected. If the substrate is fully applied with organic fertilizer and compound fertilizer, only water can be dripped, not nutrient solution. Organic substrate cultivation promoted by Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, also known as organic ecological soilless cultivation technology, is a low-cost soilless cultivation type. Peat or sawdust is added to slag, and then Gaza is used as substrate, and then sterilized chicken manure, compound fertilizer and other fertilizers are applied. During the whole growth period, only clear water is dripped without nutrient solution. At present, it has been popularized and used in Hami melon cultivation.
(3) Seedling raising technology
In hydroponics, pebbles are planted in a hollow nutrient cup, which is placed in a flowing nutrient solution pool. After 7 ~ 10 days, two true leaves can be transplanted. The cup is embedded in the hole of the cover plate of the hydroponic tank, and the root is immersed in the nutrient solution, which does not delay the emergence process and grows rapidly. If substrate culture is used, you can use ordinary seedling cups or trays, pour 0.2 dose of nutrient solution after emergence, and use two real leaves to transfer seedlings.
(4) Planting and pruning techniques
When planting watermelon seedlings, we should pay attention to keeping the root system intact and not damaging it. When transplanting into a hydroponic planting cup, it is not necessary to remove the substrate block of the seedlings, and the seedlings are directly moved into the planting cup together with the substrate. The substrate can be fixed with a small amount of pebbles, or the seedlings can be directly put into the planting cup without using it. When planting, master the planting density. Generally, every 667 square meters of greenhouse or greenhouse is planted 1200 plants. The principle is ventilation and light transmission without shading. Otherwise, it will affect photosynthesis, serious diseases, small fruits and low yield.
Indoor cultivation in greenhouse adopts single vine pruning method, and the main vine is hoisted with nylon rope to make the vine rise. Usually, fruit is left on the main vine 13 ~ 16 for artificial pollination. When the young fruit grows to the size of an egg, choose 1 fruit with correct fruit shape and good growth (small fruit varieties can sometimes keep two), remove the lateral branches below the melon node as soon as possible, leave three leaves on the melon vine for coring, and remove all the lateral vines above the melon node. When the fruit weight reaches 0.5 ~ 1.0 kg, the fruit should be covered with plastic net bags, and the net bags should be hung firmly to prevent the fruit from falling.
(5) Disease control
If there are no good control measures, the pests and diseases of melon in soilless culture will be very serious, and sometimes even devastating. Therefore, effective chemical control measures should be taken in addition to strict cleaning and disinfection of planting facilities in production. The main diseases that harm Hami melon are stem blight, powdery mildew, downy mildew and root rot, among which stem blight is difficult to control. Measures to prevent stem blight are:
① Keep dry around the stem base.
② Cover the cultivation bed tightly to reduce water evaporation.
③ Strict pruning.
4 timely prevention and control. When a diseased plant is found, the medicine is mixed with thiophanate-methyl and sterilized alum or toxic manganese zinc wettable powder according to the mass of 1: 1, and then water is added to make a thick medicine (paste), which is smeared around the stem base and rhizome, and 10 cm is smeared on the stem once every 4-7 days, and fungicides are sprayed on the leaves at the same time. If the substrate, planting pot with nutrient solution or other articles are not disinfected thoroughly, root rot may occur, which can be prevented by carbendazim, chlorothalonil and dicisone. When powdery mildew and downy mildew begin to occur in the local area, it is effective to use it for several times (colloidal sulfur for powdery mildew and antiviral alum for downy mildew).