| With the improvement of the level of science and technology and medical,the average life expectancy of the world's population has been extended,and the population of the world is increasing.Therefore,more food supplies are needed.The plant factory can be regulated and controlled by human completely and produce food crops efficiently and securely,which is an important way to slove the world's food shortage.Different crops have different requirements for the growth environment,so it is worth investigating that the issue of how to achieve the fully congtrollable characteristics of the plant factory environment and provide suitable growth conditions for it.In this research,we choose lettuce as the research object which has the largest planting area in the plant factory.Through changing the light pattern and the wind model,the effects on the quality and yield of lettuce were studied and the best planting method was selected.The experiment provided a theoretical basis and data support for vegetable cultivation in plant factories.The study set four groups of tests:1.Light 1:1 mode study.The light cycle condition include 3 hours in light and 3 hours in dark;6 hours in light and 6 hours in dark,12 hours in light and 12 hours in dark,Three crops including Italian lettuce,purple lettuce,big-leaf red coral lettuce were planted in each light cycle.2.Light 2:1 model study.The light cycle condition include 4 hours in light and 2 hours in dark,8 hours in light and 4 hours in dark,16 hours in light and 8 hours in dark,Three crops including Italian lettuce,purple lettuce,big-leaf red coral lettuce were planted in each light cycle.3.Study of different light hours.The light cycle condition include 12 hours in light,and darkness 12 hours in dark,14 hours in light and 10 hours in dark,16 hours in light and 8 hours in dark,18 hours in light and 6 hours in dark,20 hours in light and 4 hours in dark.Three crops including Italian lettuce,purple lettuce,big-leaf red coral lettuce were planted in each light cycle.4.Wind blowing mode study.The lighting condition was 20 hours in light and 4 hours in dark per day.Four groups of tests were carried out.The control group(CK)was no blowing throughout the day.Treatment 1(T1)was blowing for 4 hours during darkness.Treatment 2(T2)was blowing for 20 hours during light period.Treatment 3(T3)was blowing all day.The Italian lettuce was planted in different treatments.The result showed that:1.Light time: dark time(1:1)ratio.The best illumination mode for Italian lettuce and big-leaf red coral lettuce is 12 hours in light and 12 hours in dark,and the best cultivation mode for purple red lettuce is 6 hours in light and 6 hours in dark.2.Light time: dark time(2:1)ratio.The best illumination mode for Italian lettuce and big-leaf red coral lettuce is 16 hours in light and 8 hours in dark,and the best cultivation mode for purple red lettuce is 8 hours in light and 4 hours in dark.3.In the illumination time(12 hours?14 hours?16 hours?18 hours?20 hours)test.With the increase of illumination time,the biomass and quality indicators of Italian lettuce were increased within the range of 12 hours to 16 hours.In the case of light for 18 hours,severe tipburn occurred.Most of the biomass and quality indicators of red-leaf corals were increased with the extension of the illumination time.The biomass of purple lettuce was continuously increased from 12 hours to 16 hours.After that,the increase of biomass was not obvious,and the color continued to deepen over time.4.In the wind blowing mode,blowing the wind every day only during the lighting hours can solve the burning problem of lettuce and increase the output and quality.5.In the four tests,for fast growing lettuce,a short continuous light time is conducive to the improvement of yield and quality.For a slow growing lettuce,a longer continus light time is conducive to the improvement of yield and quality.Increasing the duration of light while increas the air flow rate can further increasing the yield and quality. |
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