A method for preventing and controlling the incidence of black heart disease of loquat before harvest

Abstract

The present invention provides a method for controlling the incidence of blackheart disease in pre-harvest nai plums, belonging to the technical field of fruit tree planting. The method solves the technical problem that calcium supplementation measures in the prior art are not effective in controlling blackheart disease in nai plums. The method comprises spraying an aqueous solution containing melatonin on the nai plum crown during the growth and development of the nai plum fruit, wherein the molar concentration of melatonin in the aqueous solution is 200 to 400 μmol·L. ‑1 This method for preventing and controlling the incidence of black heart disease in loquats before harvest can significantly reduce the incidence of black heart disease in loquats before harvest, increase the proportion of commercial fruit, and reduce the losses caused to fruit farmers due to the occurrence of black heart disease. It is simple to operate, highly efficient, and has no adverse side effects on trees and humans, and has broad application prospects.

Description

Technical Field

[0001] The invention relates to a method for preventing and controlling the incidence of black heart disease of loquat before harvest, and belongs to the technical field of fruit tree planting. Background Art

[0002] Nai Li, also known as oil nai, wood It is a plant of the genus Prunus in the Rosaceae family, native to Fujian. It is cultivated in the mountainous areas of Anhui, Hubei, Hunan, Fujian, Guangxi, and northern Guangdong. The heart-shaped fruit of the nai plum resembles a peach, and the fruit is large and beautiful. The pit is half-free, with a distinct cavity between the tip of the pit and the flesh. The peel is yellow-green, the flesh is yellow, the flesh is crisp and tender, and the flavor is rich, sweet, and fragrant. In recent years, Guangdong and Hunan have adopted bagging technology. On the one hand, it has solved the problem of the fruit being sour and unpalatable due to the widespread early harvesting caused by excessive rain during the ripening period. On the other hand, bagging to avoid light has also made the peel thinner and the color golden and translucent, significantly improving the appearance quality. It is deeply loved by consumers, and the cultivation efficiency has also been greatly improved. As a result, the cultivated area has continued to expand. In Shaoguan, Guangdong, the nai plum industry has become a local specialty agricultural industry.

[0003] Blackheart disease of pineapples is a pre-harvest disease of pineapples that has frequently appeared in Guangdong and Hunan provinces in recent years. Affected fruits appear normal in appearance and show no symptoms. Upon dissection, browning of the flesh near the core is observed, followed by spongiosis, and the fruit loses its marketability. Unlike post-harvest blackheart disease of pineapples, this disease is a pre-harvest disease, causing greater direct losses to fruit farmers. Investigations have found that the incidence of this disease in Guangdong is increasing year by year, with the incidence in severe orchards exceeding 70%, resulting in significant economic losses for fruit farmers. Furthermore, since diseased fruits lack external signs, they are easily lost to consumers, harming their interests and negatively impacting their painstakingly built brands. No scientific research has been reported on the causes of blackheart disease in pineapples. Some scholars believe that calcium deficiency in the fruit is the primary cause of blackheart disease and have proposed calcium supplementation as a preventive and control measure. However, no formal research has been reported. While developing this technology, the inventors discovered that foliar calcium supplementation is not significantly effective in preventing and controlling blackheart disease in pineapples (see Comparative Example 1). Therefore, developing efficient prevention and control measures for black heart disease of loquat before harvest is of great significance to promoting the sustainable and healthy development of the loquat industry. Summary of the Invention

[0004] In view of this, in order to solve the technical problem that calcium supplementation measures in the existing technology are not effective in preventing and controlling black heart disease of nai plum, a method for preventing and controlling the incidence of black heart disease of nai plum before harvest is provided. This method can significantly reduce the incidence of black heart disease of nai plum before harvest, is simple to operate, and is non-toxic and harmless.

[0005] The technical solutions adopted by the present invention to solve the above technical problems are as follows.

[0006] The present invention provides a method for preventing and controlling the occurrence of black heart disease of nai plum before harvest. During the growth and development of nai plum fruits, an aqueous solution containing melatonin is sprayed on the crown of the nai plum tree. The molar concentration of melatonin in the aqueous solution containing melatonin is 200-400 μmoL·L -1 .

[0007] Preferably, the molar concentration of melatonin is 300 μmoL·L -1 .

[0008] Preferably, the preparation method of the aqueous solution containing melatonin is to dissolve melatonin in anhydrous ethanol, dilute it with water to a desired concentration, and stir it evenly to obtain the aqueous solution containing melatonin.

[0009] Preferably, the purity of the melatonin is above 98 wt%.

[0010] Preferably, when the growth and development of the nai plum fruit enters the hard core stage, the aqueous solution containing melatonin is sprayed on the nai plum tree crown.

[0011] Preferably, the aqueous solution containing melatonin is sprayed three times.

[0012] Preferably, the interval between each spraying of the aqueous solution containing melatonin is 7 to 10 days.

[0013] Preferably, each time the aqueous solution containing melatonin is sprayed, the degree of moistening of the leaves of the nai plum is considered.

[0014] Preferably, the equipment used for each spraying is a sprayer.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] The method of the present invention for preventing and controlling the occurrence of black heart disease of loquat before harvest comprises spraying an aqueous solution containing melatonin on the loquat tree crown during the growth and development of the loquat fruit, thereby significantly reducing the incidence of black heart disease of the loquat before harvest, increasing the proportion of commercial fruit, and reducing the losses of fruit farmers caused by the occurrence of black heart disease. Tests have shown that the cultivation method of the present invention can reduce the incidence of black heart disease of loquat before harvest by 23.74% to 50.01%.

[0017] The method for preventing and controlling the occurrence of blackheart disease of loquat before harvest is simple to operate, can achieve prevention and control effects only by spraying on the leaves, is simple to operate, requires a small amount of dosage, and is quick to take effect. Moreover, melatonin, as an amine hormone, has no toxic effects on humans and plants, is safe and reliable, and has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0019] Figure 1 These are photographic examples of Nai Plum fruits with (top) and without (bottom) blackheart disease in Example 1 of the present invention. DETAILED DESCRIPTION

[0020] In order to further understand the present invention, preferred embodiments of the present invention are described below. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, rather than limiting the claims of the present invention.

[0021] The method for preventing and controlling the occurrence of black heart disease of loquat before harvest of the present invention comprises spraying an aqueous solution containing melatonin on the loquat crown during the growth and development of loquat fruits.

[0022] In the above technical solution, the molar concentration of melatonin in the aqueous solution containing melatonin is 200-400 μmoL·L -1 When the molar concentration of melatonin is 300 μmoL·L -1 The incidence of black heart disease of Nai Plum before harvest was most significantly reduced when the concentration of melatonin was 300 μmoL·L -1 It should be noted that there is no particular limitation on melatonin and it can be obtained by methods well known to those skilled in the art. For example, if purchased commercially, the purity of melatonin is preferably above 98 wt%. Melatonin (MT) is one of the hormones secreted by the pineal gland. Melatonin belongs to the indole heterocyclic compound, and its chemical name is N-acetyl-5-methoxytryptamine. Its structural formula is as follows:

[0023]

[0024] In the above technical solution, a preferred method for preparing the aqueous solution containing melatonin is to first dissolve melatonin in anhydrous ethanol, then dilute it with water to the desired concentration, and stir evenly to obtain the aqueous solution containing melatonin. It should be noted that the water is not particularly limited and can be pure water, deionized water, or ordinary tap water.

[0025] In the above technical solution, the specific time during the growth and development of the Nai Plum fruit is preferably when the fruit enters the hard core stage, that is, 70 days after the Nai Plum has finished flowering, to spray the Nai Plum tree canopy with an aqueous solution containing melatonin. It should be noted that spraying the aqueous solution containing melatonin at other times during the growth and development of the Nai Plum fruit can also help reduce the incidence of pre-harvest blackheart disease, but the effect is not as good as spraying it from 70 days after the Nai Plum has finished flowering.

[0026] In the above technical solution, the melatonin-containing aqueous solution is preferably sprayed three times, with the interval between each spraying being 7 to 10 days. The melatonin-containing aqueous solution is sprayed until the leaves of the nai plum are moistened. Other production management can be carried out according to the daily management of the nai plum orchard. It should be noted that other spraying frequencies, spraying intervals, and spraying levels can also help reduce the incidence of pre-harvest blackheart disease, but the effect is not as good as the above restrictions.

[0027] In the above technical solution, the equipment usually used for each spraying is a sprayer.

[0028] The terms used in the present invention generally have the meanings commonly understood by those skilled in the art, unless otherwise specified. In order to enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below with reference to the embodiments.

[0029] In the following examples, various processes and methods not described in detail are conventional methods known in the art. Unless otherwise specified, the materials, reagents, devices, instruments, equipment, etc. used in the following examples can be obtained from commercial sources.

[0030] The present invention is further described below with reference to the examples.

[0031] Example 1

[0032] The experiment was conducted in the orchard of Yijia Farm in Huangben Village, Beixiang Town, Lechang City, Guangdong Province. The trees were 6 years old and planted in a 4m x 5m size. Ten trees were randomly selected, five experimental trees and five control trees. When the fruit entered the hard core stage (70 days after flowering), the crowns of the Nai Li test and control trees were sprayed with a sprayer. The test trees were sprayed with a molar concentration of 200μmol·L -1 A melatonin-containing aqueous solution (brand: Aladdin; CAS number 73-31-4) was sprayed on the control trees, with each spray applied until the yellow-peeled leaves were moist. This was repeated three times every 10 days. Other production management procedures were carried out according to the routine management of the Nai Li orchard. Nai Li fruits were collected at maturity and dissected to determine the incidence of black heart disease. Figure 1 Examples of photos of Nai Plum fruits with black heart disease (top) and without black heart disease (bottom).

[0033] The results showed that the use of 200μmoL·L -1 The incidence of black heart disease in Nai Plum fruit treated with 200 μmoL·L melatonin solution was 33.33%, while that in the control tree was 47.33%. -1 The incidence of black heart disease in nai plum fruit was reduced by 29.58% after treatment with an aqueous solution containing melatonin.

[0034] Example 2

[0035] The experiment was conducted in the orchard of Yijia Farm in Huangben Village, Beixiang Town, Lechang City, Guangdong Province. The trees were 6 years old and planted in a 4m x 5m size. Ten trees were randomly selected, five experimental trees and five control trees. When the fruit entered the hard core stage (70 days after flowering), the crowns of the Nai Li test and control trees were sprayed with a sprayer. The test trees were sprayed with a molar concentration of 300μmol·L -1 A melatonin-containing aqueous solution (brand: Aladdin; CAS number 73-31-4) was sprayed on the control trees, with each spray applied until the yellow-peeled leaves were moist. This was repeated three times every 10 days. Other production management procedures were carried out according to the routine management of the Nai Li orchard. Nai Li fruits were collected at maturity and dissected to determine the incidence of black heart disease.

[0036] The results showed that the use of 300μmoL·L -1 The incidence of black heart disease in Nai Plum fruit treated with 300 μmoL·L melatonin was 26.33%, while that in the control tree was 52.67%. -1 The incidence of black heart disease in nai plum fruit was reduced by 50.01% after treatment with an aqueous solution containing melatonin.

[0037] Example 3

[0038] The experiment was conducted in the orchard of Yijia Farm in Huangben Village, Beixiang Town, Lechang City, Guangdong Province. The trees were 6 years old and planted in a 4m x 5m format. Ten trees were randomly selected, five experimental trees and five control trees. When the fruit entered the hard core stage (70 days after flowering), the crowns of the Nai Li test and control trees were sprayed with a sprayer. The test trees were sprayed with a molar concentration of 400μmol·L -1 A melatonin-containing aqueous solution (brand: Aladdin; CAS number 73-31-4) was sprayed on the control trees, with each spray applied until the yellow-peeled leaves were moist. This was repeated three times every 10 days. Other production management procedures were carried out according to the routine management of the Nai Li orchard. Nai Li fruits were collected at maturity and dissected to determine the incidence of black heart disease.

[0039] The results showed that the use of 400μmoL·L -1The incidence of black heart disease in the fruits of Nai plum trees treated with the aqueous solution containing melatonin was 40.67%, while that in the control trees was 53.33%. -1 The incidence of black heart disease in nai plum fruit was reduced by 23.74% after treatment with an aqueous solution containing melatonin.

[0040] Comparative Example 1

[0041] The experiment was conducted in the orchard of Yijia Farm in Huangben Village, Beixiang Town, Lechang City, Guangdong Province. Six-year-old trees were planted in a 4m x 5m format. Ten trees were randomly selected, five experimental trees and five control trees. When the fruit entered the hardcore stage (70 days after anthesis), the crowns of the Nai Li trees and the control trees were sprayed with a sprayer at a concentration of 500mg·L. -1 The control trees were sprayed with a calcium chloride (CaCl2) aqueous solution. Each spray was applied until the yellow-peeled leaves were moist. Spraying was done once every 10 days for a total of three times. Other production management was carried out according to the daily management of the Nai Li orchard. Nai Li fruits were collected at the ripening stage and opened to calculate the incidence of black heart disease.

[0042] The results showed that the use of 500mg·L -1 The incidence of black heart disease in the fruit of Nai plum trees treated with 500mg·L calcium chloride solution was 42.33%, while that in the control was 49.33%. -1 The incidence of black heart disease in nai plum fruit was reduced by 14.19% after treatment with calcium chloride aqueous solution.

[0043] In summary, foliar calcium supplementation has a certain effect on preventing black heart disease of nai plum, but the effect is not obvious; in comparison, melatonin treatment can significantly reduce the incidence of black heart disease of nai plum, has a better prevention and control effect, and can be further promoted and applied in production.

[0044] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all embodiments here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A method for preventing and controlling the occurrence of black heart disease of loquat, characterized in that: When the fruit of the nai plum enters the hard core stage, the nai plum tree crown is sprayed with an aqueous solution containing melatonin, wherein the molar concentration of melatonin in the aqueous solution is 200-400 μmoL·L -1 The number of times of spraying the aqueous solution containing melatonin is 3 times; the interval between each spraying of the aqueous solution containing melatonin is 7 to 10 days; each spraying of the aqueous solution containing melatonin is based on the degree of moistening of the leaves of the nai plum.

2. The method for preventing and controlling the occurrence of black heart disease of loquats before harvest according to claim 1, characterized in that: The molar concentration of melatonin is 300 μmoL·L -1 .

3. The method for preventing and controlling the occurrence of blackheart disease of loquat before harvest according to claim 1, characterized in that: The preparation method of the aqueous solution containing melatonin is as follows: dissolving melatonin in anhydrous ethanol, diluting it to a desired concentration with water, and stirring it evenly to obtain the aqueous solution containing melatonin.

4. The method for preventing and controlling the occurrence of blackheart disease of loquat before harvest according to claim 1, characterized in that: The purity of the melatonin is above 98 wt%.

5. The method for preventing and controlling the occurrence of black heart disease of loquat before harvest according to claim 1, characterized in that: The equipment used for each spraying is a sprayer.

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