Effects Of Spraying Potassium Fertilizer With Surfactant On The Growth And Quality Of Flue-cured Tobacco

In order to improve the utilization ratio of potassium fertilizer and the quality of tobacco leaves,we used flue-cured tobacco variety K326 as the test material to investigated.The critical surface tension of tobacco leaves was studied by contact angle method.We selected sucrose fatty acid ester,tea saponin and washing powder as the 3 kinds of surfactants.The critical micelle concentration was studied and the added concentration in the spraying solution of potash fertilizer was determined.The field spraying experiment set up 5 treatments(CK:water;CK1:potassium fertilizer;T1:potassium fertilizer+sucrose fatty acid ester;T2:potassium fertilizer+tea saponin;T3:potassium fertilizer+washing powder).We measured the effects of spraying potassium fertilizer with surfactant on the growth and quality of flue-cured tobacco The results showed that:1.The critical surface tension of tobacco leaves was 30.41 mN·m-1 and tobacco leaves are different to be wetted by the liquid.The critical micelle concentration(CMC)of sucrose fatty acid ester and tea saponin was 0.1%,0.5%,and the corresponding surface tension was 32.64 mN·m-1,40.33 mN·m-1.When the washing powder concentration was 0.2%,its surface tension was close to the critical surface tension of tobacco leaves,and the corresponding surface tension was 30.30 mN·m-1.Compared with CK1,the surface tension of T1,T2 and T3 was reduced by 60.77%,41.84%and 61.58%and the wettability increased.2.Spraying potassium fertilizer was positive to the agronomic characters of tobacco plant.After adding surfactants,the agronomic characters of the tobacco plant were further improved.The spraying potassium fertilizer with surfactant has a significant effect on the length,width and area of the maximum leaf.The length,width and area of the maximum leaf of T1,T2 and T3 were significantly higher than CK during the mature period of flue-cured tobacco.As a whole,the effect of T1 treatment on improving the agronomic traits and promoting the growth and development of tobacco plants was the best.3.With the growth of tobacco plants,the potassium content of the middle leaves decreased gradually.Spraying potassium fertilizer can increase the potassium content of tobacco leaves in different periods.After adding surfactants,the potassium content in tobacco leaves was further increased.The potassium content in middle leaves of T1 and T2 treatment was higher than CK1 in the four periods,and the difference between T1 treatment and CK1 reached a significant level.The surfactants promoted the absorption of potassium fertilizer,and then increased the potassium content of tobacco leaves.The potassium content in tobacco leaves of T1 treatment was the highest.4.The different spraying treatments had an obvious effect on the physiological indexes of tobacco leaves at different growth stages.Compared with CK1,the SOD and POD activity of T1 and T2 treatments were increased and the MDA content of T1,T2 and T3 treatments were decreased at different growth stages.The MDA content of T1 treatment was the lowest.The application of potassium fertilizer with surfactant increased the activity of SOD and POD and decreased the content of MDA in tobacco leaves.So the antioxidant capacity of tobacco leaves increased and the membrane lipid peroxidation decreased.In addition,compared with the CK1,spraying potassium fertilizer with surfactant increased the chlorophyll and carotenoid content of tobacco leaves at the peak stage of function,and enhanced photosynthesis.The photosynthesis,synthesis and accumulation of photosynthate products were strengthened.The effect of T2 treatment on increasing the content of chlorophyll and carotenoid in the early procreation of tobacco leaves was the best.5.Different spraying treatments had different effects on the stomata,waxy layer and anatomical structure during the growth of tobacco leaves.The application of potassium fertilizer promoted the opening of the stomata of tobacco leaves,but the effect was very little.After adding the surfactant,the potassium fertilizer had an obvious promoting effect on the opening of the stomata.After spraying 24 hours,the stomatal opening of different treatments was T1>T3>T2>CK1>CK.The effect of T1 treatment on stomatal opening was the best.Spraying potassium fertilizer with the surfactant could dissolve the waxy layer of the tobacco leaf.The waxy layer of T1 treatment dissolved partially.The waxy layer of T2 treatment had a little dissolving.The dissolution area of wax layer of T3 treatment was relatively large.In addition,the anatomical structure of the leaves was affected by different spraying treatments.The thickness of palisade tissue,tissue ratio and CTR of each treatment showed T1>T2>T3>CK1>CK,while the thickness of sponge tissue,total leaf thickness and SR showed CK>CK1>T3>T2>T1.T1 treatment had the best effect on improving leaf anatomical structure.6.Spraying treatments had effects on the physical properties of tobacco leaves.The CK1 treatment had a certain improvement on the physical properties of tobacco leaves.After adding surfactants,the leaf length,leaf width,single leaf weight,filling value and tensile force of T1,T2 and T3 were higher than those of CK1,and stem rate was lower than CK1.The improvement of the leaf length was the most obvious,and the difference of the leaf length between T1 and CK1 reached a significant level.7.Different spraying treatments had effects on the chemical composition of the cured tobacco leaves.Compared with CK,the application of potassium fertilizer increased the potassium content and sugar content of the middle and upper leaves,and reduced the total nitrogen and nicotine content.The ratio of sugar to alkali and the ratio of potassium and chlorine were more suitable.After adding surfactants,the sugar content and potassium content of tobacco leaves of T1 and T2 treatments increased further,and nicotine and total nitrogen content decreased.The potassium content of T1 was the highest and the chemical composition was the most harmonious.8.Different spraying treatments had effects on the neutral aroma substances content of the middle and upper cured tobacco leaves.The application of potassium fertilizer alone could increase the neutral aroma substances content and improve the quality of tobacco leaves.The neutral aroma substances content of tobacco leaves was further increased after adding surfactant in potassium fertilizer.For the middle and upper leaves,the total amount of neutral aroma substances of each treatment showed T1>T2>T3>CK1>CK.T1 treatment had the best effect on improving the carotenoid degradation products,cembranoid degradation products,neophytadiene content of the middle and upper leaves and the phenylalanine degradation products of the upper leaves.T2 treatment had the best effect on improving the degradation products of phenylalanine in the middle leaves.T3 treatment had the best effect on improving the product of mallard reaction in tobacco leaves.According to the total aroma substance content,the T1 treatment was the best.