Planting method for improving sweetness of tomatoes through stress technology

Abstract

The invention relates to the field of tomato planting, and discloses a planting method for improving sweetness of tomatoes through a stress technology, which comprises the following steps: preparing before flowering, irrigating until soil is moist but not sticky, adding sodium chloride with the concentration of 0-1.0 dS / m into irrigation water in the irrigation process, and removing lateral branches and old leaves in time; a growth regulator is sprayed 5 days before flowering, and leaves and flower buds of the plants are evenly covered with the growth regulator; according to the method, the irrigation amount and the sodium chloride concentration in irrigation water are adjusted in different growth stages of tomato plants, moderate drought and salt stress are simulated, accumulation and transportation of sugar are promoted, the irrigation amount is gradually reduced in the flowering stage and the fruiting stage, the sodium chloride concentration is increased, the sugar content in fruits can be remarkably increased, and the fruit yield is increased. The application proportion of potash fertilizer and calcium fertilizer is increased in the fruiting period and the mature period, the use of nitrogen fertilizer is reduced, the nutritional structure of plants is optimized, accumulation and transportation of sugar are promoted, and the sweetness of fruits is improved.

Description

Technical Field

[0001] The invention relates to the field of tomato planting, in particular to a planting method for improving the sweetness of tomatoes through stress technology. Background Art

[0002] Tomato is a widely planted economic crop, and its sweetness is one of the important indicators for evaluating fruit quality. Traditional planting methods mainly rely on excellent varieties and conventional management measures, such as reasonable irrigation, fertilization, and pest and disease control. However, these methods have certain limitations in improving the sweetness of tomatoes and cannot fully tap the potential of the plants.

[0003] Research in recent years has shown that the sweetness of tomatoes can be significantly improved through scientific stress technology. Stress technology mainly includes water management, fertilizer regulation, temperature management and the use of growth regulators. These technologies simulate the stress conditions in the natural environment, induce stress responses in plants, thereby promoting the accumulation and transportation of sugars and improving the sweetness of the fruit.

[0004] In order to better control environmental conditions and improve the yield and quality of tomatoes, tomatoes can be planted in a greenhouse. However, existing tomato planting technologies usually only focus on one aspect of management, such as water management or fertilizer management, and lack a comprehensive regulation method. A single management measure is difficult to comprehensively improve the sweetness and quality of tomatoes. In addition, existing planting technologies often adopt a unified management method, without fine management of the characteristics of different varieties and different growth stages, which in turn affects the maturity quality of tomato fruits and the accumulation of sugar. To solve the above problems, a planting method for improving the sweetness of tomatoes through stress technology is proposed.

[0005] The above information disclosed in this background technology is only used to increase the understanding of the background technology of the present invention and therefore, it may include information that does not constitute the prior art known to ordinary technicians in this field. Summary of the invention

[0006] In order to solve the problem of tomato planting, the present invention provides a planting method for improving the sweetness of tomatoes through stress technology.

[0007] The present invention provides a method for increasing the sweetness of tomatoes by stress technology, which adopts the following technical scheme:

[0008] A planting method for improving the sweetness of tomatoes by stress technology comprises the following steps:

[0009] S1. Preparation before flowering: irrigate until the soil is moist but not sticky. During the irrigation process, add 0-1.0 dS / m sodium chloride to the irrigation water, remove the side branches and old leaves in time, and spray the growth regulator 5 days before flowering to evenly cover the leaves and buds of the plants;

[0010] S2. During the flowering period, from 10 days before to 10 days after flowering, gradually reduce the irrigation volume to 60-70% and increase the sodium chloride concentration in the irrigation water to 1.5-2.0 dS / m;

[0011] S3, fruiting period, from 10 days after flowering to the fruit expansion period, the irrigation amount is restored to the same as in S1, sodium chloride with a concentration of 1.5-2.2 dS / m is added to the irrigation water, the application ratio of potassium fertilizer and calcium fertilizer is increased to 120%-150% of the normal fertilization amount, and the application amount of nitrogen fertilizer is reduced to 50%-70% of the normal fertilization amount. Side branches and old leaves are removed in time, and growth regulators are sprayed to evenly cover the leaves and fruits of the plants;

[0012] S4, during the maturity period, keep the irrigation amount consistent with S3, add sodium chloride with a concentration of 1-1.5 dS / m3 to the irrigation water, stop applying nitrogen fertilizer, and keep the application ratio of potassium fertilizer and calcium fertilizer consistent with that described in S3, remove excess side branches and weak leaves, spray growth regulators to evenly cover the leaves and fruits of the plants, reduce the night temperature of the greenhouse to 15-20°C, and keep the daytime temperature at 25-32°C;

[0013] S5, during the adjustment period, the irrigation amount, the concentration of sodium chloride in the irrigation water, the fertilizer ratio and the amount of growth regulators used are adjusted according to the early-maturing varieties, mid-maturing varieties and late-maturing varieties;

[0014] S6. Harvest period, obtain tomatoes with improved sweetness.

[0015] Preferably, the irrigation amount of the early-maturing variety is reduced to 70% of the normal irrigation amount starting from the 15th day after flowering for 5 days, and the irrigation amount is restored to the same as in S1, and sodium chloride with a concentration of 1.5 dS / m is added to the irrigation water from 10 days before flowering to 10 days after flowering;

[0016] The irrigation amount of the mid-maturing variety was reduced to 65% of the normal irrigation amount starting from the 20th day after flowering for 7 days, and then restored to the same level as in S1, and sodium chloride with a concentration of 1.7 dS / m was added to the irrigation water from 10 days before flowering to 10 days after flowering;

[0017] The irrigation amount of the late-maturing variety was reduced to 60% of the normal irrigation amount starting from the 25th day after flowering for 10 days, and then restored to the same level as in S1. Sodium chloride with a concentration of 2.0 dS / m was added to the irrigation water from 10 days before flowering to 10 days after flowering.

[0018] Preferably, the early-maturing variety is applied with 12-15 kg of potassium fertilizer and 6-7.5 kg of calcium fertilizer per mu during the fruiting and maturity periods, and 7.5-10.5 kg of nitrogen fertilizer per mu during the fruiting period, and the application of nitrogen fertilizer is stopped during the maturity period;

[0019] The mid-maturing varieties are applied with 15-18 kg of potassium fertilizer and 7.5-9 kg of calcium fertilizer per mu during the fruiting and maturity periods, and 10-12 kg of nitrogen fertilizer per mu during the fruiting period, and nitrogen fertilizer application is stopped during the maturity period;

[0020] For the late-maturing varieties, 18-20 kg of potassium fertilizer and 9-10 kg of calcium fertilizer are applied per mu during the fruiting and maturity stages. During the fruiting stage, 12-15 kg of nitrogen fertilizer is applied per mu, and nitrogen fertilizer application is stopped during the maturity stage.

[0021] Preferably, the growth regulator is a gibberellin solution, the spraying concentration in S1 is 10-25 mg / L, the spraying concentration in S3 is 15-35 mg / L, the spraying frequency is once every 7-10 days, and the spraying is continuous for 2-3 times.

[0022] Preferably, the spraying concentration in S3 is 20-35 mg / L in the early stage of fruiting, and 15-25 mg / L in the middle stage of fruit development.

[0023] Preferably, the spraying concentration of the early-maturing variety in S1 is 10-15 mg / L, the spraying concentration in S3 in the early fruiting stage is 20-25 mg / L, and the spraying concentration in the middle stage of fruit development is 15-20 mg / L;

[0024] The spraying concentration of the mid-ripening variety in S1 is 10-20 mg / L, the spraying concentration in S3 at the early stage of fruiting is 25-30 mg / L, and the spraying concentration in the middle stage of fruit development is 20-25 mg / L;

[0025] The spraying concentration of the late-maturing variety in S1 is 20-25 mg / L, the spraying concentration in S3 at the early fruiting stage is 30-35 mg / L, and the spraying concentration in the middle stage of fruit development is 25-30 mg / L.

[0026] Preferably, during the entire growth period, the tomato plants receive 8-10 hours of direct sunlight per day.

[0027] Preferably, the night temperature of the early-maturing varieties during the maturity period drops to 15-18°C, and the daytime temperature is maintained at 25-30°C; the night temperature of the mid-maturing varieties during the maturity period drops to 16-19°C, and the daytime temperature is maintained at 26-30°C; the night temperature of the late-maturing varieties during the maturity period drops to 17-20°C, and the daytime temperature is maintained at 27-32°C.

[0028] Preferably, the sodium chloride concentration of the irrigation water for the early-maturing variety in S3 is 1.5-1.7 dS / m, and the sodium chloride concentration of the irrigation water in S4 is 1.0-1.2 dS / m;

[0029] The sodium chloride concentration of the irrigation water for the medium-maturing varieties in S3 is 1.7-1.9 dS / m, and the sodium chloride concentration of the irrigation water in S4 is 1.0-1.3 dS / m;

[0030] The sodium chloride concentration of the irrigation water for the late-maturing varieties in S3 is 2-2.2 dS / m, and the sodium chloride concentration of the irrigation water in S4 is 1.0-1.5 dS / m.

[0031] In summary, compared with the related art, the present invention has the following beneficial effects:

[0032] By reducing the irrigation volume to 60-70% during the flowering period of tomato plants and gradually increasing the sodium chloride concentration in the irrigation water during the flowering, fruiting and ripening periods, moderate drought and salt stress can be simulated to promote the accumulation and transportation of sugars. Gradually reducing the irrigation volume and increasing the sodium chloride concentration can significantly increase the sugar content in the fruit, while improving the firmness and storage resistance of the fruit, reducing the occurrence of fruit cracking and diseases, and improving the appearance and taste of tomato fruits.

[0033] During the fruiting and ripening period, increase the application ratio of potassium fertilizer and calcium fertilizer to 120%-150% of the normal amount of fertilizer, and reduce the application of nitrogen fertilizer to 50%-70% of the normal amount of fertilizer, optimize the nutritional structure of tomato plants, promote the accumulation and transportation of sugar, and increase the sweetness of the fruit. Reasonable application of potassium fertilizer and calcium fertilizer can enhance the hardness and color of the fruit, thereby improving the quality of tomato fruit;

[0034] Spraying growth regulators before flowering is beneficial to promoting flower bud differentiation, spraying growth regulators during the fruiting period is beneficial to promoting fruit expansion, and spraying growth regulators during the ripening period is beneficial to promoting fruit ripening and sugar accumulation, further improving the sweetness of the fruit;

[0035] 4. Carry out targeted management according to the characteristics of early-maturing, mid-maturing and late-maturing varieties of tomato plants, adjust the irrigation amount, sodium chloride concentration in irrigation water, fertilizer ratio and the amount of growth regulator used, to ensure that each variety can grow under the most suitable conditions, improve the flexibility and adaptability of planting, and thus improve the overall planting effect;

[0036] 5. Through comprehensive management of tomato plants in terms of water, fertilizer, temperature, and growth stages, the healthy growth and fruit setting rate of tomato plants can be improved, and the yield and sweetness of the fruit can be increased, thereby enhancing the market competitiveness of tomatoes and increasing economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 A framework diagram for a planting method for increasing the sweetness of tomatoes through stress technology;

[0038] Figure 2 This is a flow chart for the preparation of gibberellin solution. DETAILED DESCRIPTION

[0039] The embodiment of the invention discloses a planting method for improving the sweetness of tomatoes through stress technology.

[0040] Embodiment 1:

[0041] For early-maturing tomato plant varieties, the present invention adopts a planting method for improving the sweetness of tomatoes through stress technology, comprising the following steps:

[0042] S1. Preparation before flowering: irrigate until the soil is moist but not sticky. During the irrigation process, add 0.2dS / m sodium chloride to the irrigation water, remove the side branches and old leaves in time, and spray gibberellin solution 5 days before flowering to promote flower bud differentiation, improve flowering quality and fruit setting rate. The spraying concentration of gibberellin solution is 13mg / L, and the spraying frequency is once every 8 days, spraying 3 times in a row, so that the gibberellin solution is evenly covered on the leaves and buds of the plants;

[0043] The preparation process of gibberellin solution is as follows:

[0044] a. Prepare appropriate amount of gibberellin powder, 95% ethanol, distilled water or clean water;

[0045] b. Weigh an appropriate amount of gibberellin powder

[0046] c. Dissolve the weighed gibberellin powder in an appropriate amount of 95% ethanol;

[0047] d. Stir manually until the gibberellin powder is completely dissolved in 95% ethanol to obtain the gibberellin stock solution;

[0048] e. Pour the gibberellin stock solution into distilled water or clean water and stir evenly to obtain a gibberellin solution;

[0049] Take the preparation of 10mg / L gibberellin solution as an example:

[0050] aa. Weigh 100 mg of gibberellin powder;

[0051] bb, dissolve 100 mg of gibberellin powder in 15 ml of 95% ethanol, stir evenly to obtain gibberellin stock solution;

[0052] cc, pour the dissolved gibberellin stock solution into 10 liters of distilled water or clean water, stir evenly to obtain a 10 mg / L gibberellin solution;

[0053] It should be noted that each tomato plant should be sprayed with 10-20 ml of 10 mg / L gibberellin solution, once every 10-15 days, depending on the growth stage and the growth of the plant. The gibberellin solution should be sprayed in the morning or evening, avoiding the high temperature period at noon to reduce the risk of evaporation of the solution and plant burns;

[0054] S2. During the flowering period, from 10 days before to 10 days after flowering, gradually reduce the irrigation volume to 70% and increase the sodium chloride concentration in the irrigation water to 1.5 dS / m;

[0055] It should be noted that by reducing the amount of irrigation and increasing the sodium chloride concentration in the irrigation water, moderate drought and salt stress can be simulated to promote the stress response of tomato plants, thereby promoting the accumulation and transportation of sugar, and thus significantly improving the sweetness of the fruit. Moderate drought and salt stress can also improve the hardness and storage resistance of the fruit, reduce the occurrence of fruit cracking and diseases, and improve the appearance quality of the fruit.

[0056] The sodium chloride concentration in irrigation water is adjusted as follows:

[0057] First, insert the conductivity meter probe into the irrigation water to be tested, wait for the reading to stabilize, record the conductivity value, and adjust the sodium chloride concentration in the irrigation water as needed to reach the target conductivity value;

[0058] Secondly, according to the target conductivity value and the current conductivity value, the amount of sodium chloride to be added is calculated, and the required amount of sodium chloride = (target conductivity value - current conductivity value) / 0.64 * irrigation water volume;

[0059] The value 0.64 is a conversion factor used to convert conductivity to sodium chloride concentration, representing the change in conductivity caused by dissolving one gram of sodium chloride in one liter of water;

[0060] Again, weigh the calculated amount of sodium chloride and dissolve it in the irrigation water, and stir evenly;

[0061] Finally, measure the conductivity of the irrigation water again after adding sodium chloride to ensure that the target value is reached;

[0062] For example, if the current conductivity is 1.0dS / m, the target conductivity is 1.5dS / m, and the irrigation water volume is 1000 liters,

[0063] Required amount of sodium chloride = (1.5-1.0) / 0.64*1000

[0064] =0.5 / 0.64*1000

[0065] =781.25g

[0066] Therefore, 781.25 g of sodium chloride needs to be added to 1000 liters of irrigation water to achieve the target conductivity of 1.5 dS / m;

[0067] S3, fruiting period, from 10 days after flowering to the fruit expansion period, the irrigation amount is restored to the same as in S1, sodium chloride with a concentration of 1.6 dS / m is added to the irrigation water, the application ratio of potassium fertilizer and calcium fertilizer is increased to 130% of the normal fertilization amount, the application amount of nitrogen fertilizer is reduced to 60% of the normal fertilization amount, the side branches and old leaves are removed in time, and the gibberellin solution is sprayed. The spraying concentration in the early stage of fruiting is 23 mg / L, and the spraying concentration in the middle stage of fruit development is 17 mg / L, so that the gibberellin solution is evenly covered on the leaves and fruits of the tomato plants, promoting fruit expansion, and increasing the size and number of fruits;

[0068] It should be noted that the normal application amount of potassium fertilizer, calcium fertilizer and nitrogen fertilizer is the application amount of base fertilizer before planting, among which the application amount of potassium fertilizer is 10 kg per mu, the application amount of calcium fertilizer is 5.3 kg per mu, and the application amount of nitrogen fertilizer is 15 kg per mu. Before planting, evenly spread the appropriate amount of potassium fertilizer, calcium fertilizer and nitrogen fertilizer on the soil surface, and then till and mix them.

[0069] It should be further explained that increasing the application ratio of potassium fertilizer and calcium fertilizer and reducing the use of nitrogen fertilizer can optimize the nutritional structure of tomato plants, promote the accumulation and transportation of sugar, increase the sweetness of the fruit, and reasonably apply potassium fertilizer and calcium fertilizer to enhance the hardness and color of tomato fruit and improve the quality of the fruit.

[0070] During the fruiting period, dissolve 13 kg of potassium fertilizer per mu, 7 kg of calcium fertilizer per mu, and 9 kg of nitrogen fertilizer per mu in water and apply it evenly to the soil through the irrigation system in two applications, using half the amount each time.

[0071] S4, during the ripening period, keep the irrigation amount consistent with S3, add sodium chloride with a concentration of 1.1dS / m3 to the irrigation water, stop applying nitrogen fertilizer, and keep the application ratio of potassium fertilizer and calcium fertilizer consistent with that of S3. Remove excess side branches and weak leaves, spray gibberellin solution with a concentration of 10mg / L to promote fruit ripening and sugar accumulation, improve the sweetness and quality of the fruit, reduce the night temperature of the greenhouse to 16.5℃, and keep the daytime temperature at 29℃.

[0072] It should be noted that by adjusting the temperature of the greenhouse to create a suitable temperature difference between day and night, the respiration of tomato plants can be slowed down, the accumulation of sugar can be promoted, and the quality of the fruit can be improved;

[0073] S5, adjustment period, the irrigation amount, sodium chloride concentration in irrigation water, fertilizer ratio and the amount of gibberellin solution used in the above S1-S4 are gradually adjusted, and the early-maturing variety tomato plants receive at least 8 hours of direct sunlight every day during the whole growth period;

[0074] S6. Harvest period: It usually takes 60-80 days from sowing to harvesting early-maturing varieties of tomatoes, resulting in tomatoes with increased sweetness.

[0075] Embodiment 2:

[0076] For mid-ripening tomato plant varieties, the present invention adopts a planting method for improving the sweetness of tomatoes through stress technology, comprising the following steps:

[0077] S1. Preparation before flowering: irrigate until the soil is moist but not sticky. During the irrigation process, add 0.3dS / m sodium chloride to the irrigation water, remove the side branches and old leaves in time, and spray gibberellin solution 5 days before flowering to promote flower bud differentiation, improve flowering quality and fruit setting rate. The spraying concentration of gibberellin solution is 15mg / L, and the spraying frequency is once every 9 days, spraying 3 times in a row, so that the gibberellin solution is evenly covered on the leaves and buds of the plants;

[0078] It should be noted that the preparation method of the gibberellin solution is as described in Example 1;

[0079] S2. During the flowering period, from 10 days before to 10 days after flowering, gradually reduce the irrigation volume to 65% and increase the sodium chloride concentration in the irrigation water to 1.7 dS / m;

[0080] It should be noted that the method for adjusting the sodium chloride concentration in the irrigation water is as described in Example 1;

[0081] S3, fruiting period, from 10 days after flowering to the fruit expansion period, the irrigation amount is restored to the same as in S1, sodium chloride with a concentration of 1.8 dS / m is added to the irrigation water, the application ratio of potassium fertilizer and calcium fertilizer is increased to 140% of the normal fertilization amount, the application amount of nitrogen fertilizer is reduced to 73% of the normal fertilization amount, the side branches and old leaves are removed in time, and the gibberellin solution is sprayed. The spraying concentration in the early stage of fruiting is 23 mg / L, and the spraying concentration in the middle stage of fruit development is 17 mg / L, so that the gibberellin solution is evenly covered on the leaves and fruits of the tomato plants, promoting fruit expansion, and increasing the size and number of fruits;

[0082] It should be noted that the normal application amount of potassium fertilizer, calcium fertilizer and nitrogen fertilizer is the application amount of base fertilizer before planting, among which the application amount of potassium fertilizer is 10 kg per mu, the application amount of calcium fertilizer is 5.3 kg per mu, and the application amount of nitrogen fertilizer is 15 kg per mu. Before planting, evenly spread the appropriate amount of potassium fertilizer, calcium fertilizer and nitrogen fertilizer on the soil surface, and then till and mix them.

[0083] During the fruiting period, 14 kg of potassium fertilizer per mu, 7.4 kg of calcium fertilizer per mu, and 11.1 kg of nitrogen fertilizer per mu are dissolved in water and evenly applied to the soil through the irrigation system in two applications, using half the amount each time.

[0084] S4, during the ripening period, keep the irrigation amount consistent with S3, add sodium chloride with a concentration of 1.2dS / m3 to the irrigation water, stop applying nitrogen fertilizer, and keep the application ratio of potassium fertilizer and calcium fertilizer consistent with that of S3. Remove excess side branches and weak leaves, spray gibberellin solution with a concentration of 10mg / L to promote fruit ripening and sugar accumulation, improve the sweetness and quality of the fruit, reduce the night temperature of the greenhouse to 16℃, and keep the daytime temperature at 29℃.

[0085] S5, adjustment period, the irrigation amount, sodium chloride concentration in irrigation water, fertilizer ratio and the amount of gibberellin solution used in the above S1-S4 are gradually adjusted, and the medium-ripening variety tomato plants receive at least 9 hours of direct sunlight every day during the whole growth period;

[0086] S6. Harvest period: It usually takes 80-100 days from sowing to harvesting of medium-ripening varieties of tomatoes, resulting in tomatoes with increased sweetness.

[0087] Embodiment three:

[0088] For late-maturing tomato plant varieties, the present invention adopts a planting method for improving the sweetness of tomatoes through stress technology, comprising the following steps:

[0089] S1. Preparation before flowering: irrigate until the soil is moist but not sticky. During the irrigation process, add 0.3dS / m sodium chloride to the irrigation water, remove the side branches and old leaves in time, and spray gibberellin solution 5 days before flowering to promote flower bud differentiation, improve flowering quality and fruit setting rate. The spraying concentration of gibberellin solution is 23.5mg / L, and the spraying frequency is once every 10 days, spraying 3 times in a row, so that the gibberellin solution is evenly covered on the leaves and buds of the plants;

[0090] It should be noted that the preparation method of the gibberellin solution is as described in Example 1;

[0091] S2. During the flowering period, from 10 days before to 10 days after flowering, gradually reduce the irrigation volume to 60% and increase the sodium chloride concentration in the irrigation water to 2.0 dS / m;

[0092] It should be noted that the method for adjusting the sodium chloride concentration in the irrigation water is as described in Example 1;

[0093] S3, fruiting period, from 10 days after flowering to the fruit expansion period, the irrigation amount is restored to the same as in S1, sodium chloride with a concentration of 2.1dS / m is added to the irrigation water, the application ratio of potassium fertilizer and calcium fertilizer is increased to 150% of the normal fertilization amount, the application amount of nitrogen fertilizer is reduced to 78% of the normal fertilization amount, the side branches and old leaves are removed in time, and the gibberellin solution is sprayed. The spraying concentration in the early stage of fruiting is 23mg / L, and the spraying concentration in the middle stage of fruit development is 17mg / L, so that the gibberellin solution is evenly covered on the leaves and fruits of the tomato plants, promoting fruit expansion, and increasing the size and number of fruits;

[0094] It should be noted that the normal application amount of potassium fertilizer, calcium fertilizer and nitrogen fertilizer is the application amount of base fertilizer before planting, among which the application amount of potassium fertilizer is 10 kg per mu, the application amount of calcium fertilizer is 5.3 kg per mu, and the application amount of nitrogen fertilizer is 15 kg per mu. Before planting, evenly spread the appropriate amount of potassium fertilizer, calcium fertilizer and nitrogen fertilizer on the soil surface, and then till and mix them.

[0095] During the fruiting period, 15 kg of potassium fertilizer per mu, 7.95 kg of calcium fertilizer per mu, and 11.7 kg of nitrogen fertilizer per mu are dissolved in water and evenly applied to the soil through the irrigation system in two applications, using half the amount each time.

[0096] S4, during the ripening period, keep the irrigation amount consistent with S3, add sodium chloride with a concentration of 1.3dS / m3 to the irrigation water, stop applying nitrogen fertilizer, and keep the application ratio of potassium fertilizer and calcium fertilizer consistent with that of S3. Remove excess side branches and weak leaves, spray gibberellin solution with a concentration of 13mg / L to promote fruit ripening and sugar accumulation, improve the sweetness and quality of the fruit, reduce the night temperature of the greenhouse to 17℃, and keep the daytime temperature at 32℃.

[0097] S5, adjustment period, the irrigation amount, sodium chloride concentration in irrigation water, fertilizer ratio and the amount of gibberellin solution used in the above S1-S4 are gradually adjusted, and the medium-ripening variety tomato plants receive at least 10 hours of direct sunlight per day during the whole growth period;

[0098] S6. Harvest period: It usually takes 100-120 days from sowing to harvesting late-maturing tomato varieties, resulting in tomatoes with increased sweetness.

[0099] Experimental data:

[0100] Control group: 30 tomato plants of early-maturing varieties, mid-maturing varieties, and late-maturing varieties planted without using this method;

[0101] Experimental group: 30 tomato plants of early-maturing, mid-maturing, and late-maturing varieties planted using this method;

[0102] Comparison indicators: Fruit sweetness, evaluated by measuring the soluble solids of the fruit, i.e., the Brix value; Fruit size, evaluated by measuring the average weight of the fruit;

[0103] Fruit set rate, assessed by counting the number of fruits set per unit area;

[0104] Pest and disease incidence, assessed by recording the incidence and severity of pests and diseases;

[0105] Yield, assessed by measuring total yield per unit area;

[0106] Economic benefits are evaluated by calculating the total revenue and net profit per unit area.

[0107] The comparison data of early-maturing tomato varieties are as follows:

[0108] index Control group Experimental Group Change (%) Fruit sweetness (Brix) 6.5 7.2 +10.8 Fruit size (g) 120 130 +8.3 Fruit setting rate (%) 75 85 +13.3 Incidence of pests and diseases (%) 15 10 -33.3 Yield (kg / mu) 3000 3500 +16.7 Economic benefit (yuan / mu) 6000 7000 +16.7

[0109] The comparative data of mid-ripening varieties of tomatoes are as follows:

[0110] index Control group Experimental Group Change (%) Fruit sweetness (Brix) 6.8 7.5 +10.3 Fruit size (g) 130 145 +11.5 Fruit setting rate (%) 78 88 +12.8 Incidence of pests and diseases (%) 12 8 -33.3 Yield (kg / mu) 3200 3800 +18.8 Economic benefit (yuan / mu) 6400 7600 +18.8

[0111] The comparative data of late-maturing tomato varieties are as follows:

[0112]

[0113]

[0114] Comparative data analysis of early-maturing tomato varieties: after implementing the planting method of the present invention, the sweetness of the fruit increased from 6.5 Brix to 7.2 Brix, an increase of 10.8%; the average weight of the fruit increased from 120g to 130g, an increase of 8.3%; the fruit setting rate increased from 75% to 85%, an increase of 13.3%; the incidence of diseases and insect pests decreased from 15% to 10%, a decrease of 33.3%; the yield increased from 3000kg / mu to 3500kg / mu, an increase of 16.7%; the economic benefit increased from 6000 yuan / mu to 7000 yuan / mu, an increase of 16.7%.

[0115] Comparative data analysis of mid-ripe tomato varieties: after implementing the planting method of the present invention, the sweetness of the fruit increased from 6.8 Brix to 7.5 Brix, an increase of 10.3%, the average weight of the fruit increased from 130 g to 145 g, an increase of 11.5%; the fruit setting rate increased from 78% to 88%, an increase of 12.8%; the incidence of diseases and insect pests decreased from 12% to 8%, a decrease of 33.3%; the yield increased from 3200 kg / mu to 3800 kg / mu, an increase of 18.8%; the economic benefit increased from 6400 yuan / mu to 7600 yuan / mu, an increase of 18.8%.

[0116] Comparative data analysis of late-maturing tomato varieties: after implementing the planting method of the present invention, the sweetness of the fruit increased from 7.0 Brix to 7.8 Brix, an increase of 11.4%; the average weight of the fruit increased from 140g to 155g, an increase of 10.7%; the fruit setting rate increased from 80% to 90%, an increase of 12.5%; the incidence of diseases and insect pests decreased from 10% to 6%, a decrease of 40.0%; the yield increased from 3500kg / mu to 4200kg / mu, an increase of 20.0%; the economic benefit increased from 7000 yuan / mu to 8400 yuan / mu, an increase of 20.0%.

[0117] To sum up: by subjecting early-, mid- and late-maturing tomato plants to drought, salt and temperature stress, and carrying out comprehensive management at different growth stages, the sweetness of fruits of all varieties has been significantly improved, the average fruit weight has increased, the fruit set rate has been improved, the incidence of diseases and pests has been significantly reduced, the yield has been increased, and the economic benefits have been improved, which is worthy of promotion and application in actual production.

[0118] The circuits and controls involved in the present invention are all prior art and will not be described in detail here.

[0119] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A method for increasing the sweetness of tomatoes by stress technology, characterized in that: The following steps are involved: S1. Preparation before flowering: irrigate until the soil is moist but not sticky. During the irrigation process, add 0-1.0 dS / m sodium chloride to the irrigation water, remove the side branches and old leaves in time, and spray the growth regulator 5 days before flowering to evenly cover the leaves and buds of the plants; S2. During the flowering period, from 10 days before to 10 days after flowering, gradually reduce the irrigation volume to 60-70% and increase the sodium chloride concentration in the irrigation water to 1.5-2.0 dS / m; S3, fruiting period, from 10 days after flowering to the fruit expansion period, the irrigation amount is restored to the same as in S1, sodium chloride with a concentration of 1.5-2.2 dS / m is added to the irrigation water, the application ratio of potassium fertilizer and calcium fertilizer is increased to 120%-150% of the normal fertilization amount, and the application amount of nitrogen fertilizer is reduced to 50%-70% of the normal fertilization amount. Side branches and old leaves are removed in time, and growth regulators are sprayed to evenly cover the leaves and fruits of the plants; S4, during the maturity period, keep the irrigation amount consistent with S3, add sodium chloride with a concentration of 1-1.5 dS / m3 to the irrigation water, stop applying nitrogen fertilizer, and keep the application ratio of potassium fertilizer and calcium fertilizer consistent with that described in S3, remove excess side branches and weak leaves, spray growth regulators to evenly cover the leaves and fruits of the plants, reduce the night temperature of the greenhouse to 15-20°C, and keep the daytime temperature at 25-32°C; S5, during the adjustment period, the irrigation amount, the concentration of sodium chloride in the irrigation water, the fertilizer ratio and the amount of growth regulators used are adjusted according to the early-maturing varieties, mid-maturing varieties and late-maturing varieties; S6. During the harvesting period, tomatoes with improved sweetness are obtained.

2. A method for increasing the sweetness of tomatoes by stress technology according to claim 1, characterized in that: The irrigation amount of the early-maturing variety was reduced to 70% of the normal irrigation amount from the 15th day after flowering for 5 days, and the irrigation amount was restored to the same as in S1. From 10 days before flowering to 10 days after flowering, sodium chloride with a concentration of 1.5 dS / m was added to the irrigation water; The irrigation amount of the mid-maturing variety was reduced to 65% of the normal irrigation amount starting from the 20th day after flowering for 7 days, and then restored to the same level as in S1, and sodium chloride with a concentration of 1.7 dS / m was added to the irrigation water from 10 days before flowering to 10 days after flowering; The irrigation amount of the late-maturing variety was reduced to 60% of the normal irrigation amount starting from the 25th day after flowering for 10 days, and then restored to the same level as in S1. Sodium chloride with a concentration of 2.0 dS / m was added to the irrigation water from 10 days before flowering to 10 days after flowering.

3. A method for increasing the sweetness of tomatoes by stress technology according to claim 1, characterized in that: The early-maturing varieties are applied with 12-15 kg of potassium fertilizer and 6-7.5 kg of calcium fertilizer per mu during the fruiting and maturity periods, and 7.5-10.5 kg of nitrogen fertilizer per mu during the fruiting period, and nitrogen fertilizer application is stopped during the maturity period; The mid-maturing varieties are applied with 15-18 kg of potassium fertilizer and 7.5-9 kg of calcium fertilizer per mu during the fruiting and maturity periods, and 10-12 kg of nitrogen fertilizer per mu during the fruiting period, and nitrogen fertilizer application is stopped during the maturity period; For the late-maturing varieties, 18-20 kg of potassium fertilizer and 9-10 kg of calcium fertilizer are applied per mu during the fruiting and maturity stages. During the fruiting stage, 12-15 kg of nitrogen fertilizer is applied per mu, and nitrogen fertilizer application is stopped during the maturity stage.

4. A method for increasing the sweetness of tomatoes by stress technology according to claim 1, characterized in that: The growth regulator is a gibberellin solution, the spraying concentration in S1 is 10-25 mg / L, the spraying concentration in S3 is 15-35 mg / L, the spraying frequency is once every 7-10 days, and the spraying is continued for 2-3 times.

5. A method for increasing the sweetness of tomatoes by stress technology according to claim 4, characterized in that: The spraying concentration in S3 is 20-35 mg / L in the early stage of fruiting, and 15-25 mg / L in the middle stage of fruit development.

6. A method for increasing the sweetness of tomatoes by stress technology according to claim 5, characterized in that: The spraying concentration of the early-maturing variety in S1 is 10-15 mg / L, the spraying concentration in S3 in the early fruiting stage is 20-25 mg / L, and the spraying concentration in the middle stage of fruit development is 15-20 mg / L; The spraying concentration of the mid-ripening variety in S1 is 10-20 mg / L, the spraying concentration in S3 at the early stage of fruiting is 25-30 mg / L, and the spraying concentration in the middle stage of fruit development is 20-25 mg / L; The spraying concentration of the late-maturing variety in S1 is 20-25 mg / L, the spraying concentration in S3 at the early fruiting stage is 30-35 mg / L, and the spraying concentration in the middle stage of fruit development is 25-30 mg / L.

7. A method for increasing the sweetness of tomatoes by stress technology according to claim 1, characterized in that: During the entire growing period, tomato plants receive 8-10 hours of direct sunlight every day.

8. The method for increasing the sweetness of tomatoes by stress technology according to claim 1, characterized in that: During the maturity period of the early-maturing varieties, the night temperature drops to 15-18°C, and the daytime temperature remains at 25-30°C; during the maturity period of the mid-maturing varieties, the night temperature drops to 16-19°C, and the daytime temperature remains at 26-30°C; during the maturity period of the late-maturing varieties, the night temperature drops to 17-20°C, and the daytime temperature remains at 27-32°C.

9. A method for increasing the sweetness of tomatoes by stress technology according to claim 5, characterized in that: The sodium chloride concentration of the irrigation water for the early-maturing variety in S3 is 1.5-1.7 dS / m, and the sodium chloride concentration of the irrigation water in S4 is 1.0-1.2 dS / m; The sodium chloride concentration of the irrigation water for the medium-maturing variety in S3 is 1.7-1.9 dS / m, and the sodium chloride concentration of the irrigation water in S4 is 1.0-1.3 dS / m; The sodium chloride concentration of the irrigation water for the late-maturing variety in S3 is 2-2.2 dS / m, and the sodium chloride concentration of the irrigation water in S4 is 1.0-1.5 dS / m.

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