一、棉花基本知识（Basic knowledge of cotton）.doc

一、棉花基本知识（Basic knowledge of cotton） The basic knowledge of cotton Cotton is a dicotyledonous plant of the genus malacanaceae. Good heat, good light, drought-tolerant, and avoid stains, suitable for planting in loose and deep soil. Cotton cultivation has a long history dating back to 800 BC. Our country is one of the earliest countries in the world to grow cotton. In the third century BC, the warring states period, shang shu and the book of the han dynasty, there are records of Chinas planting cotton and spinning cotton. In the history of cotton cultivation in China, four cultivars were planted: island cotton (long staple cotton), Asian cotton (coarse cotton), land cotton (fine cotton) and straw cotton (coarse cotton). In different historical periods, the main cultivars of our country are different. Asian cotton has been introduced for the longest time, with the longest planting time and the wider cultivation area. The introduction of land cotton into our country has a short history, but it has been developing rapidly and in the 1950s, it replaced Asian cotton. Cotton, which is now grown in cotton, is mostly land cotton (fine cotton), and xinjiang also has a small number of island cotton (long staple cotton). (1) characteristics of cotton variety Cotton is native to tropical and subtropical regions, and is a perennial, short - day crops. The long-term artificial selection and cultivation gradually moved north to the temperate zone and evolved into annual crops. Spring (or early summer) seeding, the present bud, flowering, strong, complete the birth cycle, to winter cold to temporary, life termination. In the process of its growth and development, as long as there is enough, the effects of temperature, illumination, just as a perennial plant, can keep long branch, leaf, budding, flowering and boll setting, continue to grow and develop, has unlimited growing and strong ability of regeneration. In the lifetime of cotton, temperature has a great influence on the developm