Studies On The Technology Of Raising Cotton Seedlings On Floating System Seedbed

The study was conducted on the growth medium and the nutrients with the material of cotton 66F1, meanwhile, the experiment of sowing-date , sowing-depth . and transplanting-seedling-age were be done. Through the research of water nursery in cottons' growth and physical characters, and the condition of growth after transplanting into the field ,and the structure of output, the paper could provide scientific basis and practical skills for the factory-cultivated cotton seedlings and efficient planting. The results are as follows:1.The initial temperature of water for the water nursery seedlings is above 17degrees stably, in other words, it is security for the water nursery seedlings after April 20 in Hunan; to ensure the high rate of seedlings' emergence and good quality, the best sowing-depth should be about 1.5 cm.2.It would be better for the medium of the water nursery in cotton seedlings in the mixed materials of Zhishi, Caotan and Zhenzhuyan, according to t-he porosity and expansivity of the medium of seedling, we can determine the best configuration to ensure high rate of seedlings' emergence and good cotton seedlings.3.The dedicated fertilizer is produces according to the need of the water nursery of cotton seedlings and the characteristics of aquatic root, which contains comprehensive and appropriate nutritional contents suited to a one-time preparation nutritional fluid for raising seedlings, and take effection during the procession.4.The best transplanting stage for the water nursery seedlings is two leaves stage or three leaves stage, and the survival seedling rate is up to 100%.T-he cotton plants' patterns-index after transplanting are better than others, which can be seen from the following section cotyledon height, the number of the main stem leaves, the situation of first branch, the height of the situation of f-irst branch, the number of fruit branches, ultimately producing higher yields.The water nursery in cotton seedlings' technology is a new type of methods to raise cotton seedlings by use of water seedbed containing porous polystyr enetrays, the medium and nutritional fluid. So the root system is developed w-ell and has a power living; and the cotton seedlings are consistent, less or no disease strains, without weeds, has a high survival seedling rate. The matching accessory transplanting technology has some advantages, such as saving labor,tr ansplanting easily, being shipped conveniently, what's more , it show great flexibility to transplant. The innovation of this thesis lies in the following:1. Cotton is a typical drought crop. The marrow organization of stem isundeveloped, and the section of the follow of the stem can not bear roots...