Effect Of Sowing Dates、Fertilization Models、 Cropping Patterns On Yield And Quality Of Sweet Sorghum

Sweet sorghum is a kind of both food crop and sugar-yielding crop,and also a new type of energy crop.Sweet sorghum,together with Chongming hairy crabs,Chongming’s white hyacinth beans,Yangtze River’s Coilia ectences Jordan and golden melons and Chongming’s narcissus,belongs to Chongming’s distinctive agricultural products.Chongming is also called the Hometown of Sugar Sorghum and at present the cultivation technique of planting sweet sorghum in Chongming is still old-fashioned and laggard with weak consciousness of industrialization and commercialization.In order to solve this problem,this thesis takes the main planting varieties of sweet sorghum in Chongming,namely sugar sorghum with spikelet in spring and sugarcane sorghum in autumn as the experimental variety with the aim of studying the influence of spring and autumn’s different sowing dates,fertilization models and cropping patterns on sweet sorghum’s yield and quality.The principal conclusions are as follows.1.The test result of sowing dates shows that as for tests in spring,the disposing growth period of March 15 th is the longest while that of April 15 th is the shortest.The plant height,stem diameter and stalk’s fresh weight are gradually declining with the postponing of sowing date during the whole growth period in the spring experiment.In other words,the disposing panicle weight of April 15 th is the heaviest and the stalk Brix of April 15 th is the highest.In the meantime,the disposing growth period of June 1st is the shortest while that of July 15 th is the longest.Besides,the plant height is the highest on June 15 th,the largest stem diameter,the heaviest fresh weight of stalk and the largest stalk Brix appear on July 1st and the longest and heaviest panicle appears on June1 st.In addition,the different sowing dates of spring and autumn exert an obvious impact on the pitch number of sweet sorghum.2.The test result of different fertilization models manifests that there exists no apparent relationship between different fertilization models in spring and autumn and sweet sorghum’s growth period.The disposing F4(Apply compound fertilizer by 300 kg per hectare before transplanting,and then respectively apply urea by 60 kg per hectare and fertilizer potash by 60 kg per hectare after transplanting,and at last apply urea by 90 kg per hectare and potash fertilizer by 6kg per acre after jointing)owns the highest plant height,the largest stem diameter,the heaviest fresh weight of stalk and the highest stalk Brix.The discrepancy of the five disposingpitch numbers with different fertilization models is also not that significant.The disposingF3(Apply compound fertilizer by 300 kg per hectare before trans planting,and then apply urea by 150 kg per hectare and fertilizer potash b y 150 kg per hectare after transplanting)has the longest and the heaviest spikelet in both spring and autumn experiments.3.The test result of different cropping patterns indicates that dual planting is good both for the enhancement of stalk’s yield and the accumulation of carbohydrate.The cropping pattern with the highest stalk yield is 80 cm in line spacing and 50 cm in row spacing in terms of dual planting.The cropping pattern with the highest stalk Brix is 100 cm in line spacing and 40 cm in row spacing in terms of dual planting.As for grain yield,single planting is higher than dual planting.The cropping pattern with the highest grain yield is 100 cm in line spacing and 20 cm in row spacing in terms of single planting.