Comparative Test on Spring Medium-sized Watermelon Varieties in Beijing

[Objectives]This study was conducted to select suitable medium-sized watermelon varieties for early spring cultivation in Beijing.[Methods]Seven watermelon varieties were collected,including Beinong Tianjiao 2,Beinong Tianjiao,Hongfuji,Yongfeng 1,Beinong Futian,Beinong Shijia,and Beinong Jinxiu,and Jingxin 2 was used as the control check(CK).The growth period,morphological traits,yield traits and fruit quality of the tested varieties were investigated.[Results]Beinong Tianjiao 2 had an earlier maturation stage,a fruit development period of 38 d and a total growth period of 118 d.It showed stable growth,with a single fruit weight of 7.56 kg,a fruit setting rate of 0.99 per plant,and a yield of 83076.9 kg/hm~2,which ranked,respectively,second,first,and second among all tested varieties,and were significantly superior to the CK.Furthermore,this variety had thin and tough peel,a bright red flesh color,high central sugar content,loose and crisp flesh,and a good taste.[Conclusions]It is preliminarily believed that it is suitable for early spring watermelon production in Beijing area.

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.

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.

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.

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.

Environmental Factors for Different Growth Stages of Small Water-melons in Spring Greenhouse in Beijing

This experiment mainly monitored the high-density planting conditions of small watermelons in spring greenhouses in Beijing by US350 environmental sensors. Besides,it analyzed the requirements for environmental factors in different growth stages of watermelons. The experiment obtained the following results.( i) Under the condition of high-density planting of small watermelons,the average air temperature range was 17. 48-21. 16℃ at the seedling hardening stage,the average air temperature range was 16. 68-25. 53℃ at the tendril elongation stage,and the average air temperature range was 15. 98-32. 06℃ at the fruiting stage. The average soil temperature range was 20. 56-23. 03℃ at the seedling hardening stage,the average soil temperature range was 20. 44-25. 51℃ at the tendril elongation stage,and the average soil temperature range was 18. 72-28. 84℃ at the fruiting stage. The average light intensity range was 2 359. 15-8 207. 44 Lux at the seedling hardening stage,the average light intensity range was 551. 98-9 170. 77 Lux at the tendril elongation stage,and the average light intensity range was 1 253. 59-9 644. 01 Lux at the fruiting stage. The average relative humidity range was 60. 69%-76. 40% at the seedling hardening stage,the average relative humidity range was 60. 85%-89. 89% at the tendril elongation stage,and the average relative humidity range was 42. 14%-93. 00% at the fruiting stage. The CO2 concentration range was 455-631 m L/m3 at the growth stage.

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.