Method for inducing field-planted ananas comosus to rapidly propagate seedlings

A method for inducing field-planted Ananas comosus to rapidly propagate seedlings, specifically comprising the following steps:

• first step:
• propagating mother plants of Ananas comosus and pruning leaves, wherein the leaves are pruned after picking fruits of the field-planted Ananas comosus, a lower leaf tip part is pruned perpendicular to a leaf direction, and a leaf base with a length of 25 cm to 30 cm is reserved, so as to ensure that rain and dew water is reserved at the leaf base to facilitate pesticide and fertilizer irrigation management in a later stage, and ensure full ventilation and sunlight reception to facilitate field management and seedling harvesting in a later stage;
• second step:
• performing sterilization and pest prevention on the mother plants of Ananas comosus, and promoting germination, wherein materials comprising 70% thiophanate methyl wettable powder or 25% carbendazim wettable powder, 90% trichlorfon soluble powder, potassium dihydrogen phosphate and a solution with 40% ethephon are prepared for later use;
• and a specific implementing method is as follows:
• (1) at a temperature less than 26° C. in an afternoon, 145 g of 70% thiophanate methyl wettable powder or 250 g of 25% carbendazim wettable powder, 200 g of potassium dihydrogen phosphate and 300 g of 90% trichlorfon soluble powder are prepared for every 100 kg of water;
• and 2 L of warm water at a water temperature of 45° C. is prepared first to fully dissolve trichlorfon in advance and then added into 100 kg of water and evenly stirred to obtain a mixture, then the mixture is added with 200 g of potassium dihydrogen phosphate and fully dissolved and evenly stirred, then the mixture is added with 250 g of thiophanate methyl wettable powder or carbendazim wettable powder and evenly stirred to obtain a solution, the solution is prepared for current use and sprayed on the mother plants of Ananas comosus after pruning to fully wet the mother plants until water is accumulated under leaf axils, and the sterilization and pest prevention are performed;
• and (2) after 7 days, at a temperature less than 26° C. in a sunshineless evening, the solution with 40% ethephon is diluted by 800 times, and sprayed on the mother plants of Ananas comosus fully until front and back leaves are wet through;
• third step:
• performing fertilization, and propagating and culturing seedlings, wherein water and a fertilizer are supplemented according to integration of water and fertilizer, (1) a first root-irrigation fertilization:
• a 100-fold water and fertilizer solution is prepared with a water-soluble compound fertilizer at a N:P:K ratio of 20:10:15, root-irrigation fertilization is performed according to 800 ml per plant, until a humidity of 40% around roots is reached after 3 hours;
• and (2) after 30 days, a second root-irrigation fertilization that is same as the first root-irrigation fertilization is performed;
• fourth step:
• promoting bud differentiation and growth, wherein a first spraying is started on a 10th day after completing the second step, (1) 15 g of cytokinin is fully dissolved with 100 ml of 0.1 mol/L hydrochloric acid and then added into 100 kg of water and evenly stirred to obtain another mixture, the other mixture is compounded with 0.2% urea and compounded with 0.2% potassium dihydrogen phosphate, evenly stirred and fully dissolved, and then sprayed on the mother plants fully until water is accumulated under leaf axils;
• and (2) after 15 days, a second spraying that is same as the first spraying is performed;
• fifth step:
• promoting growth of offset seedlings of Ananas comosus, wherein, 20 days after completing the spraying in the step (2) in the fourth step, multiple offsets exposed under multiple leaf axils are seen, and the promoting growth of offset seedlings is conducted:
• (1) a 1000-fold solution prepared with 4% gibberellic acid emulsifiable concentrate is sprayed on the mother plants fully once, after 3 days, an aqueous solution is compounded by using a 100-fold water-soluble compound fertilizer at a N:P:K ratio of 20:10:15 and 1000-fold mineral potassium fulvate, and at a temperature less than 26° C. in an afternoon, 600 ml of the aqueous solution is poured from tops of the mother plants to ensure that water is accumulated under leaf axils;
• and (2) after 15 days, the aqueous solution is poured again by the above method;
• and after 45 days of culture, the mother plants produce 3-5 offset seedlings with a length of 20-30 cm required in planting, and the seedlings are harvested;
• and
• sixth step:
• after a seedling production and propagation in the second step to the fifth step and a consequent first seedling harvesting, implementing operations as follows:
• (1) the second step to the fifth step are repeated in a first round, so that another seedling production and propagation is performed for a second seedling harvesting, and a seedling yield of a single mother plant is multiplied for a first time;
• and then (2) the second step to the fifth step are repeated in a second round so that further another seedling production and propagation is performed for a third seedling harvesting.