A dual regulation method for flowering and fruiting periods of tamarind trees

Abstract

This invention discloses a dual regulation method for the flowering and fruiting periods of tamarind trees. Specifically, it involves dual management and regulation during the fruiting and pre-flowering stages and the flowering period. The management during the fruiting and pre-flowering stages includes (1) winter water control, (2) chemical treatment, and (3) watering to promote flowering. The management during the flowering period includes (1) pollen collection, (2) hybrid pollination, and (3) bagging. The regulation method provided by this invention allows tamarind trees to flower earlier and in a concentrated manner over a large area, which is beneficial for concentrated pollination and fruit setting, facilitates concentrated ripening and unified harvesting during the ripening period, improves management efficiency, reduces labor costs, increases tamarind yield, and increases income. This demonstrates that the regulation method of this technical solution is effective and has prospects for widespread application.

Description

Technical Field

[0001] This invention relates to a method for regulating the flowering and fruit setting of plants, specifically a method for dual regulation of the flowering and fruiting periods of tamarind trees. Background Technology

[0002] Tamarind, scientifically known as *Tamarindus indica* Linn., is also called sour bean. In China, it is mainly distributed in the dry-hot valleys of Yunnan Province, as well as the Guangdong and Guangxi regions and Hainan Island in South China. It is a typical tropical tree species, with areas having an average annual temperature above 19℃ being its suitable habitat. Wild tamarind trees are widely distributed in several major dry-hot valley basins in Yunnan Province, such as Yuanmou in the Jinsha River basin and Yuanyang and Yuanjiang in the Red River basin. Tamarind trees are tall trees, reaching heights of over 20 meters. They have a well-developed taproot and strong vitality, growing not only near water sources in dry-hot valleys but also in relatively barren mountainous and sloping areas far from water sources. It is a widely adaptable tree species, thriving in places with high temperatures, long hours of sunshine, dry climates, and distinct wet and dry seasons.

[0003] Tamarind trees are mostly found in tropical regions and are deep-rooted species. Tamarind trees have a distinct main trunk and strong upright growth. If they are not pruned and shaped, or if human intervention is not carried out, the main trunk will grow upward on its own, resulting in dense lateral branches. This will not only lead to many inner branches, a small and closed canopy, and poor ventilation and light penetration, but will also reduce the fruiting area, lower the flowering and fruiting rate, and cause poor growth and development.

[0004] Tamarind is generally an evergreen tree, the type that grows new leaves before old leaves fall off. Leaf renewal typically occurs year-round when moisture and temperature are suitable. In hot, dry valleys, this renewal is more pronounced during the alternation of dry and wet seasons. In areas with ample moisture, renewal is slower, with little or no leaf drop. In hot, dry valleys, new shoots emerge around the rainy season in April and May, coinciding with flower bud differentiation, which typically occurs from May to October. Individual florets gradually grow and open as the inflorescence develops, resulting in a long flowering period. The flowers mature and bloom sequentially, extending the flowering period into September and October. Therefore, tamarind trees can be pollinated and bear fruit from May to October, with peak flowering typically concentrated between May and July. While pollination and fruit setting are possible after flowering, the fruit set period for tamarind is long, generally requiring at least eight months or longer from the onset of fruit set to harvest maturity. This means that tamarind trees that flower and set fruit after July may not be ripe by harvest time.

[0005] Tamarind trees have a strong clumping tendency and an indistinct main trunk. During the dry season, in relatively humid environments, unmanaged or poorly managed tamarind trees develop dense, heavy branches. Insufficient moisture leads to vigorous vegetative growth, inhibiting reproductive growth. Insufficient light within the canopy results in low flower bud differentiation, numerous vigorous shoots, and ultimately, few or no flowers. During the flowering period, tamarind trees are severely affected by environmental factors (such as water, temperature, and light). Insufficient rainfall and low humidity negatively impact fruit set. Tamarind flowers are pale yellow with some light red sepals, and the overall flower color is not very vibrant. Nectar is also scarce, with virtually no fragrance, making it unattractive to pollinating insects. This results in low pollination efficiency and low fruit set. Tamarind has edible and medicinal value, is a good raw material for timber processing, and also has good ecological value. However, currently, the genetic traits of tamarind fruits are unstable, exhibiting significant alternate bearing (biennial bearing), low fruit set, and a phenomenon of one fruit per thousand flowers, leading to low and unstable yields. Summary of the Invention

[0006] The purpose of this invention is to provide a dual regulation method for the flowering and fruiting periods of tamarind trees. Specifically, it involves dual management and regulation during the fruiting period, the pre-flowering period, and the flowering period of tamarind trees to artificially control concentrated flowering and fruit setting, thereby increasing the fruit setting rate and yield of tamarind.

[0007] To achieve the above objectives, the present invention provides a method for dual regulation of the flowering and fruiting periods of tamarind trees, comprising the following:

[0008] Fruiting period and pre-flowering management, including:

[0009] 1) Winter water control: Stop watering and fertilizing after the tamarind fruit enlargement period ends, until the fruit harvest is completed;

[0010] 2) Chemical treatment: Chemical treatment should be carried out after the fruit is fully harvested to promote the growth of acidic leaves;

[0011] 3) Watering to promote flowering: Watering should begin two weeks after the pesticide treatment is completed, and wait for flowering to occur;

[0012] Flowering period management, including:

[0013] 1) Pollen collection: Collect the flowers of the male parent and collect the anthers;

[0014] 2) Pollination: Select the flowers of the mother plant for pollination, and bag them after pollination.

[0015] Preferably, the aforementioned male parent flowers are those whose inflorescences have grown to 10cm, and whose state is characterized by the loss of sepals at the base of the inflorescence, full buds, and loose flower buds.

[0016] Preferably, the above-mentioned method for collecting anthers is as follows: remove the anthers from the flower, bake them for 2 hours at a distance of 20cm-30cm above the anthers using an 11w-13w light bulb, and collect the pollen after shaking.

[0017] Preferably, the female parent in the above pollination is a female flower with the male stamens removed.

[0018] Preferably, the above-mentioned treatment involves diluting an ethephon aqueous solution with an active ingredient content of 40% and spraying it onto the leaves of tamarind, wherein the optimal dilution ratio is 1667 times.

[0019] Preferably, the watering should be done thoroughly in one go, and watering should be done at least once every two weeks.

[0020] The present invention solves the problem and has the following advantages:

[0021] (1) Based on the low self-compatibility of tamarind trees, the flowering period regulation in this method can meet the hybridization breeding needs of tamarind trees. This method is relatively simple to operate and has a high success rate of hybridization pollination.

[0022] (2) The flowering period control measures of this method can make tamarind trees bloom in a concentrated and large-scale manner in advance. After concentrated flowering, it is conducive to concentrated pollination and fruit setting, and also conducive to concentrated ripening during the fruit ripening period, which facilitates unified harvesting, improves management efficiency, and reduces labor costs. Detailed Implementation

[0023] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] Note: Methods not specifically described in this application are conventional methods in the field, and reagents and consumables not specifically given are conventional reagents and consumables in the field.

[0025] Example 1: A method for dual regulation of flowering and fruiting periods in tamarind trees

[0026] Addressing the issues of low pollination efficiency and low fruit set rate in tamarind trees, this embodiment provides a method for artificially controlling concentrated flowering and fruit set in tamarind trees to improve the fruit set rate. This method mainly comprises two parts: fruiting period and pre-flowering management, and flowering period management, as detailed below:

[0027] I. Management during the fruiting period and before flowering

[0028] (1) Water control in winter

[0029] In the dry and hot valleys of Yunnan, winter months are generally a dry season with little rainfall. During this time, the tamarind fruit enlargement period ends, and the fruit length and thickness cease to grow. Winter water control in these regions typically begins in January or February. Watering is stopped at this time, and aside from some foliar fertilizers used to improve fruit quality, no further fertilization is generally applied until the previous year's fruit is fully ripe and ready for harvest. Without winter water control, the tamarind fruit ripening period will be prolonged, the fruit stalks will not dry easily, leading to harvesting difficulties and reduced efficiency. Delayed harvesting will also affect subsequent tamarind germination.

[0030] (2) Chemical treatment

[0031] The fruit ripens generally from March to early April. After the previous year's fruit is fully ripe and harvested, it is treated with ethephon, produced by Zhongmian Xiaokang Biotechnology Co., Ltd., in a 40% effective ingredient aqueous solution. The minimum dilution concentration is 1667 times. Spraying the diluted solution onto the tamarind leaves, using 9 mL of ethephon (1667 times diluted) per 15 kg of water, effectively promotes leaf drop in tamarind trees. Five concentration gradients of ethephon and a blank control were designed, as shown in Table 1. The effects of different concentrations of ethephon on tamarind leaf drop are shown in Table 2. It can be seen that except for the low-concentration treatment (P1), all other concentrations had a significant effect on tamarind leaf drop. There were no significant differences between P1, P2, P3, and P4, and no significant difference between P5 and the control (CK). Applying pesticides after fruit harvest can effectively promote the growth of tamarind leaves, preparing them for concentrated germination. Otherwise, if the flowering period lasts too long, it will not be conducive to concentrated fruit setting, thus affecting the fruit setting rate and yield.

[0032] Table 1 Ethephon Concentration Gradient

[0033]

[0034] Table 2. Effects of different concentrations of ethephon on leaf defoliation of tamarind trees.

[0035]

[0036] (3) Watering promotes flowering

[0037] Watering should be done two weeks after the pesticide treatment to effectively promote the germination of tamarind trees after leaf fall. Each watering should be thorough, with each tree receiving at least 0.08 cubic meters of water, depending on the site conditions and the size of the canopy. Trees with a canopy width exceeding 5 meters should be watered at least once every two weeks. Sufficient watering before germination effectively improves the quality of sprouting buds, ensuring plump buds and promoting flower bud differentiation. Watering promotes flowering in the dry-hot valleys of Yunnan until the end of the dry season and the arrival of the rainy season.

[0038] II. Flowering Period Management

[0039] Tamarind trees generally begin to sprout in mid-to-late April in dry-hot river valleys. In the Yuanjiang River basin, this happens one to two weeks earlier than in the Jinsha River basin. Based on the phenological characteristics of tamarind, flower bud differentiation usually occurs from May to October. The flowering period is long, lasting until the end of September or the beginning of October. Because of the long fruit-setting cycle, the tamarind fruits that set in August and September are not easy to ripen and are difficult to harvest. Therefore, the best time for tamarind trees to be pollinated is in May and June.

[0040] (1) Pollen collection

[0041] After the leaves of the tamarind tree sprout and the inflorescence appears and grows to 10cm, mature and unopened flowers of the selected male parent are collected before 10:00 AM. Flowers with fallen sepals at the base of the inflorescence, plump buds, and loosened flower buds are collected in concentrated groups. After collection, the petals and stigmas are removed, and the anthers are placed uniformly on paper in a dry, windless place. An 11W-13W light bulb is placed 20cm-30cm above the paper and heated for 2 hours. After two hours, the pollen is collected in 5-10mL test tubes, mixed, and shaken well; the pollen will then disperse. Generally, only buds on inflorescences longer than 10cm are sufficiently plump and mature. On shorter inflorescences, individual buds are not mature enough, affecting the quality and quantity of pollen collection. Heating the anthers with an 11W-13W light bulb effectively promotes anther dehiscence and improves the efficiency of anther collection.

[0042] It is known that the tamarind inflorescence is a gradual process of growth and flowering. As the inflorescence grows, the buds at the base open first. After pollination, the buds will set fruit if they can, and the buds that cannot be pollinated will fall off. Therefore, the inflorescence can reach more than 10 cm in length. The tamarind buds at the base of the inflorescence are full and have enough time to develop. The stigma and stamens are fully developed, which is conducive to controlling pollen quality and collecting pollen.

[0043] Through optimization of pollen treatment conditions, it was found that when using a light bulb with a wattage of less than 10W for two hours, the anthers did not split sufficiently, and some anthers failed to split, resulting in pollen not being released. When using a light bulb with a wattage greater than 13W for two hours, the pollen viability decreased to 54.3%. However, when using light bulbs with a wattage of 11W-13W for two hours, the pollen viability was 81.4% and 78.7% respectively, meeting the pollination requirements.

[0044] Based on this, the optimal placement of a 12W light bulb was explored. It was found that when the bulb was placed less than 20cm above the anthers and baked for 2 hours, the pollen viability decreased to 50.7%. When the bulb was placed more than 40cm above the anthers, the anthers did not split sufficiently and the time required was prolonged. Some anthers failed to split, and the pollen could not be released. A placement of 20-30cm effectively improved the anther splitting process, resulting in good pollen release and maintaining a pollen viability of around 80%.

[0045] Therefore, the optimal pretreatment method for pollen before pollination is as follows: place the removed anthers in a dry, windless place, place an 11w-13w light bulb at a height of 20cm-30cm and bake for 2 hours. After two hours, the pollen can be collected for use in pollination.

[0046] (2) Hybrid pollination

[0047] After pollen collection, hybridization and pollination can be carried out on the same day. After selecting a good hybridization mother tree, select mature and unopened flowers. Select flowers with sepals fallen off at the base of the inflorescence, plump buds, and loosened flower buds for pollination. First, peel off the sepals and petals, use tweezers to break off and remove the male flower's stamens, and then use a cotton swab to dip the male flower pollen from the pollen tube and apply it to the stigma of the pistil to complete the hybridization and pollination work.

[0048] (3) Bagging

[0049] Immediately after hybridization and pollination, bagging should be carried out. Use 8cm x 12cm non-woven white cloth bags, tying them to the base of the inflorescence with string. An 8cm x 12cm non-woven white bag should cover the entire inflorescence, and the opening should be tied at the base. Bags that are too large will be blown by the wind, affecting fruit set after pollination.

[0050] Statistical analysis of the fruit set rate of tamarind shows that, by adopting the control method provided by this invention, the fruit set rate of tamarind flowers after pollination reached 42.8%, while the natural pollination fruit set rate of tamarind during the flowering period without this method was only 3.4%. This further demonstrates that the technical solution provided by this invention can significantly improve the fruit set rate of tamarind flowers and significantly increase tamarind yield.

[0051] In summary, this invention provides a planting management method to increase tamarind yield. Specifically, by implementing dual management and control during the fruiting period, pre-flowering period, and flowering period of tamarind trees, the trees can flower earlier and in a concentrated manner over a large area, which is conducive to concentrated pollination and fruit setting, and facilitates concentrated ripening and unified harvesting during the ripening period. This improves management efficiency, reduces labor costs, increases tamarind yield, and increases income, indicating that the control method of this technical solution is effective and has prospects for widespread application.

[0052] Although the present invention has been described in detail through the preferred embodiments above, it should be understood that the above description should not be considered as a limitation of the present invention. Various modifications and substitutions to the present invention will be apparent to those skilled in the art after reading the above description. Therefore, the scope of protection of the present invention should be defined by the appended claims.

Claims

1. A method for dual regulation of the flowering and fruiting periods of tamarind trees, characterized in that, Includes the following: Fruiting period and pre-flowering management, including: 1) Winter water control: Stop watering and fertilizing after the tamarind fruit enlargement period ends, until the fruit harvest is completed; 2) Chemical treatment: Chemical treatment should be carried out after the fruit is fully harvested to promote the growth of acidic leaves; 3) Watering to promote flowering: Start watering two weeks after the pesticide treatment is completed, and wait for flowering; Flowering period management, including: 1) Pollen collection: Collect the male parent flowers and collect the anthers; 2) Pollination: Select the flowers of the mother plant for pollination, and bag them after pollination.

2. The dual regulation method according to claim 1, characterized in that, The male parent flower is the flower after the inflorescence has grown to 10cm, and its state is that the sepals at the base of the inflorescence have fallen off, the flower buds are full, and the flower buds are loose.

3. The dual regulation method according to claim 1, characterized in that, The female parent plant used in pollination is a female flower with the male stamens removed.

4. The dual regulation method according to claim 1, characterized in that, The chemical treatment involves diluting an ethephon aqueous solution with an active ingredient content of 40% and spraying it onto the leaves of tamarind.

5. The dual regulation method according to claim 4, characterized in that, The optimal dilution factor is 1667 times.

6. The dual regulation method according to claim 1, characterized in that, The watering should be done thoroughly in one go, and at least once every two weeks.

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