The Effect Of Different Lights And Plant Density And Harvest Time On Yield And Quality Of Lettuce In Plant Factory

Plant factory is a resource-intensive model of production plants,the light,temperature,water,gas and fertilizer can be precise controled.It is also not occupied the agricultural land and producted safety and no pollution.The yield per unit area can be open field cultivation reached even a hundred times more than a few times,in extreme environmental conditions can protect the food supply and food safety.In addition,it also has energy-saving,environmental protection and good product quality.Therefore,the plant factory is an important means to achieve sustainable development of agriculture,its development can help solve important problems of human survival and development are facing.In this paper,in order to solve the plant factory energy consumption,less environmental studies and lettuce cultivation techniques,we study the impact on yield and quality of lettuce by different spectral,density,planting density and harvest time,we determine to explore suitable illumination light-control technology and crop cultivation techniques in closed plant factory,while improving the yield and quality of plant products.At the same time,to reduce manufacturing costs and operating costs of artificial light,development of efficient artificial light sources provide a scientific basis,and providing a theoretical basis and data support for plant cultivation plant other crops.In this study,we used the "green-collar" lettuce as test materials,explores the the impact on yield and quality of lettuce by different spectral,density,planting density and harvest time.The results are as follows.1.lettuce under red light,the height growth significantly faster than the other treatments,soluble protein,free amino acids,total chlorophyll content is low,the chlorophylla/b were significantly higher than other treatments;RB31 treatment swells green leaves content,vitamin C?Vc?,soluble sugar content was significantly higher than other treatments,the lowest nitrate content of lettuce best color quality;lettuce fresh and dry weight under RB11 treatment,higher plant height,carotenoid content,lettuce color quality is better than other treatments;lettuce treated under slow growth RB13,fresh and dry weight,plant height,chlorophyll content,carotenoid content,VC and other significantly smaller than the other treatments,but the crispness of the largest lettuce;soluble sugar under treatment B,the minimum sugar content,minimal sweetness.The results showed that:lettuce biomass accumulation under treatment RB31 more,better quality,can be used as a suitable spectrum of plants cultivated lettuce plants.2.lettuce under 150?mol·m^-2·s^-1 light intensity,the height,leaf area,water content and vitamin C content was significantly higher than other treatments;lettuce under 200?mol·m^-2·s^-1 light intensity,lettuce shoots fresh weight and total weight and free amino acids were significantly higher than other treatments;250?mol·m^-2·s^-1 light intensity handling raw cabbages highest weight;300?mol·m^-2·s^-1 light intensity treatment swells leaves the area,including water,chlorophyll a,chlorophyll a+b and carotenoids were less than other treatments,a high content of soluble sugar and nitrate.The results showed that:200?mol·m^-2·s^-1 light intensity treatment,the lettuce biomass accumulation and more high water content,lettuce quality is better than other treatments,plant lettuce plants to produce the most appropriate choice of light intensity.3.The spacing of 15cm × 20cm handle,the highest yield of lettuce,lettuce,fresh and dry weight was also higher;leaf area in the 15cm × 20cm with the next higher value;root activity at 15cm × 25cm,20cm × 20cm handle stronger in 10cm × 20cm with the next total chlorophyll,carotenoid than the other treatments,there was no significant difference between the other treatments;carotenoids in 10cm × 20cm maximum processing;the chlorophyll a/b in a 10cm × 10cm,15cm x 15cm,15cm × 25cm processing under significantly larger than other treatments,and the lowest in 10cm × 20cm with the next.Soluble sugar,sucrose content in 20cm × 20cm handle higher soluble protein,free amino acids in processed under 10cm × 20cm high content of vitamin C in the treatment under 20cm × 25cm more content.Studies have shown that:the planting density spacing of 15cm× 20cm,lettuce yield per plant and populations are high yield,lettuce vigorous growth,photosynthesis strong,good quality,cost savings,can get higher yields and economic benefits,planting density is more appropriate choice.4.The lettuce harvested for 21d,the biomass accumulation and small in soluble protein,soluble sugar,vitamin C and other content;The lettuce harvested for 28d,the biomass is also smaller,less sugar,chlorophyll a,chlorophyll b and other content;35d lettuce biomass accumulation and more,higher soluble sugar,soluble protein,sugar,amino acid,total chlorophyll,carotenoid content,such as quality indicators;The lettuce harvested for 42d,biomass accumulation more,but slow growth,low soluble protein,soluble sugar content.The results showed that:lettuce biomass accumulation under 35d achieved more and the good quality,it is can be used as the best harvest time for lettuce plant factory.In summary,the R:B=1:1 is the best spectrum of plant lettuce plants,200?mol·m^-2·s^-1 is the optimal density,spacing of 15cm × 20cm is the best planting density,35d for the best harvest period.Best spectroscopy,optical density,planting density and harvesting of plants not only can significantly promote plant growth and yield and quality of lettuce,but also lettuce and factory production costs can be reduced.The data can be used as a lettuce plant factory production theory.