Suitable Zoning For Unseasonal Strawberry Planting In Greenhouse In The Western Sichuan Plateau

In this study,strawberry "Monterrey" was used to conduct facility cultivation experiments at the strawberry base in Songpan County,Aba Prefecture,Western Sichuan Plateau,and artificial environment control experiments at the Artificial Climate Laboratory of Nanjing University of Information Science and Technology.Meteorological data inside and outside the facility for strawberry plant growth and development data,physiological parameters and fruit quality data were collected in the experiments.Based on the existing research results,determine the suitablity index of unseasonal strawberry and its grading standard.Combined with historical and meteorological data,analyze spatiotemporal and spatial distribution of the suitability of unseasonal strawberry in the Western Sichuan Plateau.Then,combining the greenhouse microclimate model,geographical factors,human factors,the fine division suitability zoning for greenhouse-cultivated unseasonal strawberry in the West Sichuan Plateau was formed.The main findings are as follows:(1)Comparing the growth of strawberries planted in greenhouses and open fields,it was found that the dynamic changes of dry matter accumulation and single leaf area of strawberries planted in both open field and greenhouse basically conformed to the classic "S" curve characteristics.However,the growth rate,dry matter accumulation,and leaf expansion rate of strawberry planted in greenhouses are faster than those grown in open fields,and the taste of strawberry fruits in greenhouses was also better,and the sugar content and vitamin C content were higher than those in open fields.Through the simulation of unseasonal strawberry growth,it was found that the model based on LTF method was more accurate in the simulation of dry matter accumulation and single leaf area of unseasonal strawberry in greenhouse,whose determination coefficients of 1: 1 line of the simulated and measured value was above 0.95.The LTE model's simulation results had a high degree of credibility.(2)The photosynthetic rate of strawberry leaves under CK treatment was always the highest followed by low temperature 5 ?> low temperature 10 ?> high temperature 30 ?> high temperature 35 ?.It was revealed that the photosynthetic capacity of strawberry leaves would be reduced by whether high temperature or low temperature treatments;However,the strawberry leaves can recover a certain part of photosynthetic capacity under the treatment of low temperature 10 ? for 10 days continuously,which reflected the self-regulation ability of strawberry plants under low temperature conditions.By analyzing the chlorophyll fluorescence dynamics curve and parameters,it can be seen that high temperature conditions can stimulate the light absorption capacity,inhibit energy transmission and conversion processes of photosynthesis of strawberry leaves,as well as the large dissipation of energy would cause the photosynthetic efficiency of leaves to decrease.While the yield and efficiency of photosynthesis energy absorption,conversion process of strawberry leaves were all reduced under low temperature condition.(3)Based on the analysis of climate suitability,the study found that the suitable period of temperature for unseasonal strawberry growth in the Western Sichuan plateau was concentrated between May and September,and the suitable period of precipitation started from early April to early June and from early September to mid-October.Under the synergy of temperature and precipitation,the suitable climate period for strawberry growth in the Western Sichuan Plateau can be extended from mid-April to mid-October.The research found that the climatically suitable areas for unseasonal strawberries in the Western Sichuan plateau were mainly concentrated in Liangshan Prefecture,such as Ganluo,Yuexi,Mianning,Xide,Xichang,Busch,Puge,Ningnan;the sub-suitable areas mainly covered the eastern and central-western parts of Liangshan Prefecture,whose altitude below 3000 m,and the central-southern parts of Aba Prefecture and eastern Ganzi Prefecture,whose altitude were between 2000 m and 5000 m.(4)Based on GIS technology,combined with greenhouse climate simulation,geographical and human factors,the suitability zoning of unseasonal strawberry farming in the West Sichuan Plateau was formed.The results showed that the areas suitable for unseasonal strawberry farming were mainly distributed in the southwest part of Aba and Liangshan Prefecture,which accounted for 9.78% of the total area of the Western Sichuan Plateau.At the same time,there were many sub-suitable areas scattered around the suitable areas,which accounted for 16.35% of the total area of the Western Sichuan Plateau.All suitable area had the characteristics of "more in the southwest,less in the northeast" in terms of spatial distribution and area ratio.The research results can make up for the gaps in the meteorological research on unseasonal strawberry production in plateau,and provide scientific basis and technical guidance for the site selection of large-scale unseasonal strawberry production in the plateau and the optimization of greenhouse regulation.On the other side,the results can provide a reference of environment control methods for other plateau plant production,and lay the foundation for the research work on the development and utilization of climate resources in the Western Sichuan Plateau.