Current Situation and Development Proposals of Agricultural Facilities(Planting)Application in Beijing

Facility agriculture is an essential carrier for promoting stable production and supply.In2020,the planting area of facility agriculture in Beijing(290098000 m2)accounted for 29.06%of the total planting area of crops(998078000 m2),and the output value accounted for 46.56%.In2022,Beijing Agricultural Technology Extension Station organized relevant departments to summarize and evaluate the agricultural facilities in Beijing through consultation materials,interviews,questionnaires,and field trips,combining survey data and statistical data to draw the following conclusions.Facilities play a major supporting role in stabilizing production and ensuring supply.The number of traditional greenhouses is extensive and covers a large area,so special planning and classification upgrades are urgently needed.Facilities are rich in scientific and technological resources,but the mode of production is out of date.It is of great significance to improve the comprehensive production capacity of facility agriculture and promote the healthy and stable development of facility industry in Beijing to increase the utilization rate of facility agriculture land,strengthen the support of facility science and technology,and cultivate the socialized service organization of facility.

Control Means and Data Analysis of Environmental Factors of Facility Watermelon in Beijing Area

In this study, the environmental indicators(including temperature, light, air relative humidity and CO_2 concentration) of facility watermelon in Beijing area were monitored with US350 environmental sensor during the whole growth period. The results showed that in the solar greenhouses in Beijing area, the average air temperature was in the range of 10.67-29.95 ℃ during the whole growth period of watermelon, the average soil temperature ranged from 16.92 to 35.10 ℃, the average light intensity changed from 268.37 to 13 842.60 lx, the average air relative humidity ranged from 52.40% to 94.26%, and the average CO_2 concentration was in the range of 455-631 ml/m^3; and in the spring greenhouses in Beijing area, the variation range of average air temperature was 14.05-29.84 ℃ during the whole growth period of watermelon, the average soil temperature ranged from17.47 to 28.12 ℃, the average light intensity was in the range of 55.80-12 858.64 lx, the average soil moisture content ranged from 18.19%-34.56%, the variation range of average air relative humidity was 20.72%-96.26%, and the average CO_2 concentration was in the range of 351-544 ml/m^3.

Technical Regulations for Facility Watermelon Production in Beijing

Aiming at the problems of low standardization, unstable quality and low commodity rate of facility watermelon cultivation technology in Beijing, to meet the demand for high-quality and standardized supply capacity of the watermelon industry, the technical regulations for facility watermelon production in Beijing area were formulated, mainly including the environmental conditions of the producing area, cultivation techniques, pest control and harvesting. This regulation can provide a reference for the standardization of facility watermelon production.

Cultivation Techniques of Beibei Type of Pumpkin in Spring Greenhouse of Beijing Region

Beibei pumpkin has the characteristics of early maturity,high yield,strong disease resistance,cold resistance,strong ability of continuous fruiting,excellent quality and easy cultivation,and its cultivation in spring greenhouse of Beijing region could effectively improve yield and commodity.In this paper,cultivation techniques of Beibei pumpkin in spring greenhouse are introduced,including cultivation of strong seedlings,planting,management after planting and storage after harvest.

Effects of Different Concentrations of Paclobutrazol on Seedling Quality of Small Seedless Watermelon in Autumn

[Objectives]The paper was to explore the effects of different concentrations of paclobutrazol on seedling quality of small seedless watermelon in autumn.[Methods]The leaves of watermelon seedlings were sprayed with 30,50,80 and 120 mg/L paclobutrazol at cotyledon expansion stage,and those sprayed with tap water were used as control.[Results]All the treatments of paclobutrazol effectively inhibited the excessive growth of watermelon at seedling stage,significantly enhanced the leaf quality of watermelon seedlings and promoted root growth.The seedlings treated by 50 mg/L paclobutrazol had the best performance compared with the control:a decrease of hypocotyl by 37.9%,an increase of plant dry weight by 46.55%,significantly increased seedling strength index,deep green leaf color,thick leaves,an increase of specific leaf weight by 28.13%,and significantly heavier root weight and longer length.[Conclusions]The results will provide a reference for strong seedling cultivation of small seedless watermelon.

Evaluation indices of sour flavor for apple fruit and grading standards

In order to establish grading standards of evaluation indices for sour flavor of apples, 10 indices of samples from 106 apple cultivars were tested, including： malic acid（Mal）, oxalic acid（Oxa）, citric acid（Cit）, lactic acid（Lac）, succinic acid（Suc）, fumaric acid（Fum）, total organic acids（To A, the sum of the six organic acids tested）, titratable acid（TiA）, acidity value（AcV）, and pH value. For most of the cultivars studied（85.8%）, the order of the organic acid contents in apples was Mal〉Oxa〉Cit〉Lac〉Suc〉Fum. Mal was the dominant organic acid, on average, accounting for 94.5% of To A. Among the 10 indices, the dispersion of pH value was the smallest with a coefficient of variation of only 8.2%, while the coefficients of variation of the other nine indices were larger, ranging between 31 and 66%. There were significant linear relationships between Mal and two indices（ToA and AcV） as well as between ToA and AcV. There were significant logarithmic relationships between pH value and four indices： Mal, TiA, ToA, and AcV. All the equations had very high fitting accuracy and can be used to accurately predict related indices. According to this study, Mal, ToA, and AcV of apple were normally distributed, TiA was close to normally distributed, whereas pH value had a skewed distribution. Using the fitted normal distribution curves, the grading standards of Mal, TiA, ToA, and AcV were established. The grading node values of pH value were obtained using the logarithmic relationship between pH value and Mal. The grading standards of these five indices can be used to evaluate the sour flavor of apple. This study provides a scientific basis for evaluating apple flavor and selecting apple cultivars.

Effects of Planting Mode on Growth, Yield and Quality of Mini-watermelon under Soilless Cultivation

[Objective]The paper was to screen out planting mode suitable for mini-watermelon in spring greenhouses under soilless cultivation.[Method]The effects of single row planting with one main vine and one lateral vein,double row planting with one main vine and one lateral vein,and double row planting with two lateral veins on the growth period,growth,fruit quality and yield of mini-watermelon were studied.[Result]The planting mode of single row planting with one main vine and one lateral vein was adopted.The earliest date of harvest was May 28;the fruit-setting rate was 106.3%;and the single fruit weight was 1.33 kg.The lowest abnormal fruit rate was 0.73%;the highest yield was 54465.45 kg/hm^2,and the central sugar content was the highest of 12.95%.[Conclusion]Single row planting mode under soilless cultivation has certain demonstration and popularization prospect.

Comparative Test on New Small Watermelon Varieties with Red Flesh under Soilless Culture Conditions

In order to screen out the small watermelon varieties with red flesh suitable for soilless cultivation and to meet people's requirements of high-quality watermelons,comparative tests were conducted on 6 small watermelon varieties with red flesh under soilless culture conditions in 2018.Based on the data of field traits,yield traits,quality traits and commercial traits,the integrated results showed that ‘Chuanqi 2’ had good quality and high yield,and the overall performance was the best.

Effects of Different Planting Densities on Growth, Yield and Quality of Mini-watermelon under Soilless Cultivation

[Objective]The paper was to study the effects of different plant densities on growth,yield and quality of mini-watermelon under soilless cultivation.[Method]Five planting densities were designed under double row planting with one main vine and one lateral vein in soilless cultivation,including 5.25×10^4,3.90×10^4,3.15×10^4,2.70×10^4 and 2.25×10^4 plants/hm^2.[Conclusion]Under the planting density of 3.15×10^4 plants/hm^2,the yield of mini-watermelon was the highest of 58.719 t/hm^2;the yield of plot was the highest of 260.97 kg;the central sugar content was the highest of 13.20%;the earliest date of harvest was June 1,ranking second;the fruit setting rate was 108.9%;the single fruit weight was 1.72 kg;and the malformed fruit rate was 0.48%.[Conclusion]Under soilless cultivation,3.15×10^4 plants/hm^2 is the best planting density.

Effects of Different Amino Acid Fertilizers on Growth,Development and Quality of Mini Watermelon under Substrate Cultivation

In order to select suitable mini watermelon varieties for spring greenhouse cultivation under substrate cultivation,the field character,yield character,quality character and trade trait of six new mini watermelon varieties with red flesh were compared in the test.The results showed that mini watermelon applied with alanine and arginine had obvious advantages in quality character,yield character and trade trait.The yields reached 3876.8 and 44120.20 kg/667m2;the weight of single melon reached 1.98 and 2.10 kg;and the central sugar content reached 13.34%and 13.25%,respectively.Meantime,mini watermelon was juicy,sweet,tasty and refreshing,and was suitable for planting under substrate cultivation.

Introduction and Selection of Dandelion Varieties under the Forest

[Objectives]To select dandelion varieties suitable for forest land in Beijing suburb plain.[Methods]With the local varieties in Beijing as control,four dandelion varieties,Hebei 2,Shandong 1,Anhui 1 and Henan 1 were introduced,and the growth differences,effective components and yield indexes of different varieties were analyzed.[Results]The leaf and root yield of Henan 1 dandelion was significantly higher than that of the control,and the content of caffeic acid in the root was also higher than the standard of Pharmacopoeia.[Conclusions]On the whole,the dandelion variety Henan 1 is suitable for demonstration planting under the young forest in the plains of Beijing suburb.

Screening of Red-flesh Small Watermelon Varieties for Substrate Cultivation in Spring Greenhouses

[Objectives] This study was conducted to screen small watermelon varieties suitable for spring greenhouses. [Methods] The field traits, yield traits, quality traits and commodity of 6 new red-flesh watermelon varieties were compared. [Results] "Jingmei 3 K" and "Sumeng No.5" had obvious advantages in quality traits, yield traits, and commodity traits. The yield reached 62 163.3 and 63 733.5 kg/hm2, respectively;the single melon weights reached 2.16 and 2.21 kg, respectively;and the central sugar content reached 13.2% and 13.1%, respectively. Meanwhile, the juice contents were high, and the taste was sweet and refreshing. They are suitable for planting under the condition of substrate cultivation technology. [Conclusions] This study provides a theoretical basis for large-area substrate cultivation and production.