| The aeroponic culture could get rid of the drawbacks of traditional soil cultivation effectively,solve the root gas environment sufficiently,utilize nutrients and water efficiently,and had broad application prospects.The use of aeroponic culture technology to plant potato original seed could also fully solve the problems of continuous cropping defects,serious diseases and long growth cycles in traditional techniques.Nutrient solution was the key to obtain high yield and high quality of the potato with aeroponic culture.But the content of nitrate nitrogen in the composition of most nutrient solution was high,which led to unsatisfied yield effect and seriously affected the nutritional quality of potato.At present,there were few studies on the spray frequency at home and abroad,and the frequency values selected in each study were quite different and not concentrated.In order to screen out the optimum combination of nutrient solution concentration and spray frequency in the aeroponic system to cultivate original potato seed,and optimize the effect of breeding the original potato seed.In this study,three nutrient solution concentration(0.6A,0.8A,A)and three spray frequency(spray interval 10 min,15 min,20 min)were used in the vegetative growth period,and three nutrient solution concentration(0.8A,A,1.2A)and three spray frequency(spray interval 20 min,25 min,30 min)were used in the tuber growth period to cultivate potato in aeroponic system from 2017 to 2018.the main findings were as follows:1.Under the influence of two test factors,the plant height,stem diameter,root length,root volume and leaf number of potato cultivated by aeroponic system increased fast initially and increased slowly then,the stolons number continued to increase,and the leaf area increased first and reduced then.Among them,when the nutrient solution concentration was 0.8A and A in the vegetative growth period,A and 1.2A in the tuber growth period,it was beneficial to the growth of potato plants in aeroponic culture system;the comprehensive effect of spray frequency was better when the spray interval was 20 min in the vegetative growth period and 30 min in the tuber growth period.2.From vegetative growth period to the tuber growth period,the content of chlorophyll a decreased,the difference between chlorophyll b and carotenoid content was not obvious,the potato root activity was increased when the nutrient concentration was 0.6A in the vegetative growth period and 0.8A in the tuber growth period.The content of soluble sugar and soluble protein among the treatments were not significant,but the nitrate content was significantly different,and the content increased as the growth time increased.The concentration of nutrient solution had a significant effect on the potato physiological characteristics compared with the spray frequency in the aeroponic system.Among them,the concentration of the nutrient solution was better when it was 0.8A in the vegetative growth period and A in the tuber growth period.3.When the nutrient solution concentration was 0.8A and A in the vegetative growth period,A and 1L2A in the tuber growth period,which was conducive to the accumulation of potato dry matter in the aeroponic system and the nutrient solution concentration and the spray frequency had a significant impact on it.The spray frequency was best in vegetative growth period when it sprayed at "interval 20 min work 40 s",and was best in tuber growth period when it sprayed at "interval 25 min work 40 s".4.During the whole growth period of the potato in the aeroponic cultivation,the absorption of nitrogen and phosphorus by various organs(except the tuber)showed that uptake dose was more in vegetative growth period and slowed down in tuber growth period;The absorption of potassium in vegetative growth period was increased first and decreased then,and the absorption of potassium by various organs in tuber growth period was generally higher than vegetative growth period(except tubers).The absorption of NPK by tubers showed an increasing trend.Compared with the spray frequency,the nutrient solution concentration has a more significant effect on the absorption of nitrogen,phosphorus and potassium of potato plants,and when the nutrient solution concentration was A in the vegetative growth period and 1.2A in the tuber growth period,the absorption was higher.5.Nutrient solution concentration and spray frequency could significantly affect the potato yield in aeroponic cultivation.Among them,the treatment of A nutrient solution concentration and 20 min spray interval time in the vegetative growth period;1.2A nutrient solution concentration 30 min spray interval time in the tuber growth period,the total potato volume,total potato weight,G>10 g potato number and conversion yield were the highest,with 69.43 grains/plant,172.34 g/plant,4.14 and 9302.28 g/m2 respectively.Based on the results of integrated principal component cluster analysis and the analysis of various indicators of aeroponic potato,when the nutrient solution concentration was 0.8A and A in the vegetative growth period,A and 1.2A in the tuber growth period;when the spray interval was 20 min in the vegetative growth period and 30 min in the tuber growth period,which was beneficial to the growth,nutrient uptake and yield of the potato growth. |
