Effects Of Seaweed Fertilizer On Growth And Quality Of Chinese Kale

Seaweed fertilizer is a natural seaweed extract with good affinity to terrestrial plants.More important,seaweed fertilizer contains comprehensive nutritional compounds and has the ability to reinforce disease resistance of vegetables,increase soil productivity and is eco-friendly.Chinese kale(Brassica oleracea var.alboglabra Bailey),a member of Brassicaceae family.Generally,the edible part of Chinese kale are bolting stems which not only have a sweet flavor and crisp taste,but also rich in secondary metabolites such as glucosinolates,loved by consumers.Therefore,indepth study on the effects of different concentrations of seaweed fertilizer on the yield and quality of Chinese kale is of great practical significance to meet the demand of high-efficiency production of hydroponic kale.The experiment 1 main results were as follows:(1)The plant height and yield of Chinese kale were lower in all seaweed fertilizer treatments compared with CK.The stems diameter increased by 4.84% in 1200 times treatment,while the other two treatments were smaller compared with CK.(2)The content of photosynthetic pigments increased significantly in all seaweed fertilizer treatments compared with CK.All seaweed fertilizer treatments significantly increased the VC content of the Chinese kale,which diluted 1200 times the maximum increase.The nitrate content of Chinese kale was promoted in all seaweed fertilizer treatments.(3)The content of FRAP,total phenolics and flavonoids of Chinese kale were enhanced in all seaweed fertilizer treatments.When diluted 1200 times,the content of TPC(total phenolic compounds)and TF(total flavonoids)increased by 24.00% and 72.59%compared with CK.When diluted 1000 times,the FRAP content increased 18.53%.The use of seaweed fertilizer increased the GLS(glucosinolates)content of Chinese kale.(4)The use of seaweed fertilizer increased element contents,such as nitrogen,phosphorus,potassium and sulfur in the edible part of Chinese kale,but suppressed theIVaccumulation of those mineral elements.The inhibition effects decreased with the increase of dilution multiples.The experiment 2 main results were as follows:(1)The use of low concentration of seaweed fertilizer could increase the biomass of Chinese kale.The total fresh weight and shoot fresh weight were higher in all seaweed fertilizer treatments than that in CK.Compared with CK,shoot fresh weight in 1400 times treatment was 20.17% higher.(2)The use of low concentration seaweed fertilizer significantly increased the content of photosynthetic pigments in Chinese kale.When diluted 1400 times total chlorophyll were the highest compared with CK,which were significantly increased by 50.21%,respectively.Promoted the content of soluble protein compared with CK,which was significantly increased by 31.35% when diluted 1400 times.When diluted 1400 times,the nitrate contents were 34.81% lower,respectively.(3)The contents of FRAP,TPC and TF in all seaweed fertilizer treatments were higher than CK,thus the antioxidant capacities of Chinese kale were enhanced.When diluted 1400 times,the content of FRAP,TPC and TF were 18.87%,21.55% and 28.36% higher than CK,respectively.The contents of GLS in all seaweed fertilizer treatments were higher than CK.Comparing to CK,the contents of total GLS,total aliphatic GLS and total indole GLS in1400 times treatments were enhanced 58.07%,56.85.% and 65.54%,respectively.When diluted 1400 and 1600 times,the contents of 4-pentane sulfur glycosides were increased127.89% and 122.14%,respectively.Besides,the contents of 2-propylene-based sulfur glycosides and indole-3-methyl sulfur glycosides were 35.35% and 74.72% higher than CK,respectively.(4)The use of low concentrations of seaweed fertilizer promoted the contents of mineral elements,such as P,Ca and S,in the edible part of the Chinese kale.When adding1400 times of seaweed fertilizer,the content of N,P,K,Ca,Mg and S in edible part of Chinese kale were markedly increased compared with CK.To sum up,the use of seaweed fertilizer in nutrient solution could promote the contents of photosynthetic pigments,thus enhanced the photosynthetic capacity of Chinese kale.High concentrations of seaweed fertilizer inhibited the biomass of Chinese kale,but low concentration of seaweed fertilizer with a dilution of 1400 times promoted the growth of shoot and increases the yield.Also,adding seaweed fertilizer can increase the contents of GLS in the edible part of Chinese kale,and high concentrations of seaweed fertilizer were more potent.In addition,the seaweed fertilizer could increase the contents of FRAP,TPC and TF,consequently enhanced the antioxidant capacities of Chinese kale.Moreover,the nutritional qualities of kale were improved by seaweed fertilizer.