Test And Extension Of Yam's Effective And High-Quality Planting Technology In Southwest Hubei

Yam, which is comparatively preponderant agricultural product in Enshi, plays animportant role in increasing efficiency of agriculture, income of farmer and exportexchange. The backwardness of planting technology has restricted the production of yamfor long time. The studies were mainly focused on the following aspects: (1) yam's highlyeffective planting technology;(2) Yam seedling's reproduction technology; (3) Plantingmanners and water demand; (4) thimble planting technology, (5) pest management; (6)storage, processing and utilization. By analysing the problems in production of yam,combining local production situation, the author puts forward yam's highly effective andhigh-quality planting technology in Enshi.Random Plot Design was used to study the influence of the following plantingmethods on yam's yield: ratio of the elements in fertilizers, duration of seedling's usage,planting density and period, rotation of crops, etc. The results showed that the yield intreatment with fertilizer at ratio of N₂₀P₁₅K₁₀ was 30.3% higher than that incontrol.Nitrogen fertilizer had the greatest effects on yield,, while potassium fertilizerless and Phosporous fertilizer the least. The yield in treatment by planting seedlingswith 5 years' usage was 21.21% lower than that with one year's usage. In treatment withfresh seedlings, yield increases distinctly. The optimal planting season for yam was first20 days in April, and the optimal density was 3700 plants per 667m². Continuouscropping of yam in the same field or trough will affect not only the yield, but also thequality. With 4 years' continuous cropping, incidence of black spot reaches to 93.8%and the yield decreases 61.4%.The studies on techniques of reproduction of seeds of yam had been carried out. Thetechniques of reproduction was drawn as followings: Select the bigger seeds as thesowing materials; spread the wet sand with thickness of 3cm at 20-25C 15days before thesowing; place one layer of seeds and then one layer of wet sand (with thickness of 3cm),and so on till the total thickness of 30-50cm; sow the yam sprouts when the buds grow tothe size of rapeseeds; or soak the seed for 30-40min in 1% sulfur urea and0.4%chlorohydrin, and sow after air-drying. The optimum of density for seed sowing was15000-20000 plant per 667m²; and the right time for sowing is to sow the seeds beforefrost and let them germinate after frost. Plastic membrane should be covered for a goodgrowth at early stage and plentiful harvest.The studies about effects of yam's planting ways, amounts and times of irrigation onthe yield had been carried out in a random block design. It demonstrated that there was significant difference in yield between conventional planting and hole-digging planting,while also the significant difference in yield between 250m³ and 350m³ of waterirrigation, and no significant difference between times of irrigation. The highest yield wasobtained through hole-digging plant, amount of irrigation at 300m³ per 667m².Studies on complete tube-covering and semi-tube covering techniques showed thatthe key factor was the depth of covering tubes buried. The optimum position was 20cm indepth with an angle of 20°.The investigation of yam pests in Southwestern Hubei showed that the majordiseases included yam's anthracnose, yam's black-spot disease, and the major insect pestswere Agrotis ypsilon, Pleonomus canaliculatus Faldermann. the major measures forcontrolling of yams' insect pests were to make precious forecast, use scientifically thechemical pesticides, and apply the proper time. With regard to the disease control, the keymeasures included good seed treatment, healthy lplanting, and control with pesticides.Studies had also been carried out on the storage and processing of yams. Yamsshould be stored in piles or in basket to reduce the occurrence of storage disease. Yamscan be processed to make bionic food, bevereage, yogurt and medicine.Traditional planting ways are mostly used in Enshi. With the extension of highlyeffective and high-quality planting technology, it will promote the production of yam. Itwill also reduce labour intensity, and the production cost, increase the efficiency ofproduction and improve remarkably the quality and quantity of yams. Nevertheless, jointefforts from the yam planting enterprises and the extension department of agriculturaltechnology are required to extend the technology for the further development of yams inEnshi.