Effect Of Potassium Nutrition On Yield And Quality Of Tumorous Stem Mustard

Tumorous stem mustard (Brassica juncea coss var tumida tsenee lee) is a special agri-product in Chongqing. It is mostly distributed along the coastwise of Yangtze River and its planting area is about 40000 hm~2 at present. Tumorous stem mustard planting had been one of main industries of peasants for increase earning in Three Gorge area. However, there are lots of questions which will descending yield and quality of tumorous stem mustard and lower economic benefit on fertilization such as preference of nitrogen fertilizer, shortage of potassium fertilizer, imbalance of NPK-nutrition usage, and so on. The superabundance of nitrogen and shortage of potassium will affect yield, appearance and inside quality of crop and vegetables, but there is seldom research about potassium influencing yield and quality of tumorous stem mustard. To reveal output effect and quality effect of potassium nutrition on tumorous stem mustard, and realize differences of potassium nutrition between conventional tumorous stem mustard bred (Yong'anxiaoye} which is extensively used in production at present and hybrid tumorous stem mustard bred (Fuzaerhao), and definitude best dosage of potassium, and provide reference to production of tumorous stem mustard with high quality and yield, aiming at the questions above, this paper studied influences of different dosage of potassium fertilizer on yield and quality of tumorous stem mustard and responses of different tumorous stem mustard bred to potassium fertilizer by combining field experiment with lab analysis. The results are following:The potassium fertilizer obviously increased yield of tumorous stem mustard on the basis of nitrogen and phosphorus fertilizer, and yield of treatment fertilized potassium fertilizer was 12%～36%(average higher 23.4%) greater than it of treatment not fertilized potassium. Yield of tumorous stem mustard increased with dosage of potassium within scope of 0-300kg/hm~2. The highest yield was 40822.2kg/hm~2 while amount of application of potassium was 300kg/hm~2, and yield of treatment not fertilized potassium was 36.2% less than highest yield. Yield of tumorous stem mustard decreased with amount of application of potassium while the amount exceeds 300kg/hm~2. Quadratic equation could be used to describe the relation between amount of potassium fertilizer and yield of tumorous stem mustard:Y=29746.8245+64.3905*X-0.107266*X~2 (R~2=0.8743**, F=13.87)Y stood for yield of tumorous stem mustard (kg/hm~2), X stood for application amount of potassium fertilizer (kg/hm~2) .Potassium fertilizer can increase the content of amino acid in the tumorous stem mustard, and improve nutritional quality of it. The average content (13.6g/kg) of amino acid of the tumorous stem mustard of all treated with potassium fertilizer is 20% higher than those not fertilized potassium. Within the range of 0-300kg/hm , the content of amino acid in the tumorous stem mustard increased with applicated amount of potassium fertilizer. For example, a mean content of 14.8 g/kg for amino acid attained under treated by potassium fertilizer of 300 kg/hm~2 that was higher than that of did treated. There were markly differences between different types of amino acid caused by potassium fertilizer use. Applying potassium increased content of necessary amino acid and palatable taste amino acid, and there wasn't significant influence on sweet taste and bitter taste amino acid. The potassium fertilizer had the big difference to the different type amino acid influence, the employment potassium fertilizer enhanced the tumorous stem mustard essential amino acids and the fresh taste amino acid content obviously, was not big to the sweet taste amino acid and the bitter taste amino acid influence. The fresh taste amino acid content and the sweet taste amino acid content of treatment are 25% and 24.8% higher than the not constructing potassium. The content of fresh taste amino acid and the sweet taste amino acid of tumorous stem mustard is increasing within the range of 0-300kg/hm~2 with increase of potassium consumption, the content of amino acid is increased to biggest while reaching 300kg/hm~2, but as the potassium further increases, the content of amino acid begins to drop. In 17 kind of amino acid contents, the highest is the glutanic acid content which reach 476～562mg every 100g fresh weight, accounting for 37% of 17 kinds of amino acids total amounts, that may be the reason of tumorous stem mustard so fresh; and the second highest is the asparagine acid (8.3%), and the lowest is asparagine acid to account for 1.4% of amino acids total amount; and the proportion of other amino acids is between 2% to 5.8%.Increas in content of soluble sugar in the tumorous stem mustard was favoured by a within measure potassium fertilizer applying. The content of soluble sugar of the tumorous stem mustard increased with potassium consumption within the range of 0-450kg/hm~2, all treatment had an average value of 22.7% was higher than those of did use potassium.The content of soluble sugar show the biggest value of 19.1 mg/kg (FW) under condition of use potassium of 450kg/hm~2, which improved up 36% when compaired with did treated case. Potassium fertilizer increase the nitrate of tumorous stem mustard, but the influnce on the vitamin C of tumorous stem mustard is not obvious.Increase in K level in both stem and leaf of the tumorous stem mustard was with potassium fertilizer application. Mean K adsorbed by abovegraound part of all treatment is higher of 48.9% than that of not treatment. Of toal K adsorbed, there is about 72% that distributed in stem of tumorous stem mustard. The average usage of all treatment is 20.9%.Potassium fertilizer is increasing the absorption of nitrogen and phosphorus. Consideration comprehensive the yield, quality and the usage of potassium of tumorous stem mustard, when the dosage of potassium is 275-300 kg/hm~2, the benefit is optimal under the condition of the experimentation.The compare researches were carried out in the common species and the hybridize species (Yonganxiaoye and Fuza 2~#), the results show that the yield in stem did exhibite a significant difference bewteen two specieses under a using range of 0-150 kg/hm~2 of K. fertilizer. However, the stem yield for the Yonganxiaoye have a higher of 21.8% than that of the Fuza 2~# when use amount of 300 kg/hm~2 for K fertilizer, but the leaf yield of the latter was more higher than the former. The leaf and stem ratio of Fuzaerhao is lower than Yonganxiaoye.it means that Yonganxiaoye is more better in formation of economic yield(stem).In controls, K adsorbed by the Fuza 2~# is less 25.68 kg/hm~2 than the Yonganxiaoye. However, in treatments, K absorption had not obviously difference between two specieses. The efficiency of potassium fertilizer ultilized by the Fuza 2~# is higher than the Yonganxiaoye under the same treatment, suggest that the Fuzaerhao is distinct depend on potassium when compare with Yonganxiaoye, and the latter could better use potassium of soil.The content of amino acid had a considerable difference between the Fuzaerhao and the Yonganxiaoye. Different kinds of amino acid in the Yonganxiaoye is always higher than the Fuzaerhao, the amino acid of total, essential, fresh flavor, sweet taste and bitter flavor in the Yonganxiaoye exceeded in the Fuza 2~#, were 11.5%, 8.1%, 9.1%, 9.5% and 9.9%, respectively. The flavor may have some difference between two kinds of tumorous stem mustard due to different contents of the amino acid, the future study will need.