Current issue

• 2022 Vol.38 No.21 Published:25 July 2022

  Large-Panicle Rice Varieties: Synergistic Enhancement of Yield and Nitrogen Use Efficiency ZHONG Xuefen, CHONG Haotian, GUO Zhan, HUANG Liying, ZHANG Yunbo 2022, 38 (21):  1-6.  DOI: 10.11924/j.issn.1000-6850.casb2021-0843 Abstract + ( 185 )   HTML ( 5 )   PDF ( 1944KB )   ( 59 ) This study aims to clarify the differences in yield and nitrogen use efficiency of rice varieties with different types of panicles, and to explore their corresponding high-yield and high-efficiency cultivation techniques. Field experiments were conducted with a large-panicle variety ‘Y-Liangyou 900’ and two multi-panicle varieties ‘Fengliangyou 4’ and ‘C-Liangyouhuazhan’ under three nitrogen treatments (0, 180 and 270 kg N/hm2). The results showed that the average yield of ‘Y-Liangyou 900’ was 10.83 kg/hm2 under the three nitrogen treatments, which was 17.3% and 5.5% higher than that of ‘Fengliangyou 4’ and ‘C-Liangyouhuazhan’, respectively. The yield advantage of ‘Y-Liangyou 900’ was mainly due to higher grain number per panicle and dry matter accumulation. The agronomic nitrogen use efficiency of ‘Y-Liangyou 900’ was 310.6% and 28.5% higher than that of ‘Fengliangyou 4’ and ‘C-Liangyouhuazhan’, respectively, and the nitrogen partial productivity was 23.5% and 6.7% higher, respectively. In summary, the yield and nitrogen use efficiency of large-panicle rice varieties are significantly higher than those of multi-panicle varieties, indicating that large-panicle varieties might have the synergistic enhancement potential of yield and nitrogen use efficiency of rice.

  Changes of Photosynthetic Characteristics of Black Wheat and the Influence on Yield ZHANG Yaowen, ZHAO Pengtao, LI Jiming, ZHAO Xiaoguang, SHANG Yi, ZHANG Zhenlan, ZHAI Zhouping, LI Longhua 2022, 38 (21):  7-16.  DOI: 10.11924/j.issn.1000-6850.casb2021-0531 Abstract + ( 237 )   HTML ( 4 )   PDF ( 7444KB )   ( 33 ) In order to provide a theoretical basis for breeding high-yield black wheat varieties by photosynthetic pathway, 5 black wheat lines and 1 common wheat variety (CK) were used as materials, the changes of 5 photosynthetic characteristic indexes (PCI) of flag leaves and the relationship between PCI and grain yield (GY) were studied during 7 growth periods from heading stage (HS) to early mature stage (EMS).The results showed that: compared with CK, the chlorophyll contents (CC) of the 5 black wheat lines in heading stage to late grain filling stage (HS-LSFP) were significantly lower. The green leaf area (GLA) of the 5 black wheat lines were lower in LSFP but higher in EMS, the growth rates of biological yield (BY) were significantly higher in early to middle grain filling stage (ESFP-MSFP) but significantly lower in flowering stage to early grain filling stage (FS-ESFP) and final grain filling stage to early mature stage (FSFP-EMS).The grain filling rate (GFR) of the 5 black wheat lines were significantly lower in ESFP-MSFP and middle to late grain filling stage (MSFP-LSFP). All the 5 PCIs had significantly positive correlation with GY. The change rates of the 5 PCIs were positively correlated with GY in heading stage to flowering stage(HS-FS) and flowering stage to early grain filling stage (FS-ESFP), while were negatively correlated with GY in middle to late grain filling stage (MSFP-LSFP), late to final grain filling stage (LSFP-FSFP) and final grain filling stage to early mature stage (FSFP-EMS). The correlation degree between the PCI and GY was green leaf area (GLA)>transpiration rate (Trm)> net photosynthetic rate (Pn)>stomatal conductance (Gs)>chlorophyll content (CC). The correlation degree between the change rate of PCI and GY was Pn>Gs>Trm>CC>GLA. The correlation degree between the PCI and GY in different periods was MSFP>ESFP>LSFP>FSFP>HS>FS>EMS, while the correlation degree between the change rate of PCI and GY in different periods was FS-ESFP>HS-FS>ESFP-MSFP>FSFP-EMS>LSFP-FSFP>MSFP-LSFP. In conclusion, it is an important way to improve the yield of black wheat by breeding the lines with higher CC, Pn, Gs and GLA of flag leaves in heading stage to middle grain filling stage.

  Drought Resistance of Sugar Beet Seedling: Identification and Index Screening LI Wangsheng, WANG Xueqian, YIN Xilong, SHI Yang, XING Wang 2022, 38 (21):  17-23.  DOI: 10.11924/j.issn.1000-6850.casb2021-1173 Abstract + ( 227 )   HTML ( 1 )   PDF ( 2386KB )   ( 26 ) To screen the drought-resistant sugar beet germplasm resources at the seedling stage and determine the drought-resistant indexes, in this study, 24 beet germplasms provided by the National Beet Germplasm Bank were used as materials, PEG-6000 was used to simulate drought stress, and Hoagland hydroponic solution (CK) under normal growth condition was used as control. Sugar beet seedlings were treated with 6% PEG-6000 for 7 days, and the phenotype indexes of aboveground and underground parts were determined. The results showed that the effects of drought stress on leaf fresh weight, root fresh weight, leaf saturated fresh weight and leaf dry weight were significant, with a decrease rate of more than 50%, and the root-to-shoot ratio of sugar beet germplasm increased significantly after drought stress. Cluster analysis divided the 24 beet germplasms into four categories, of which, ZT000516 belonged to one category alone, which was the most drought-resistant germplasm resource. The second category had strong drought-resistance, including ZT000078, ZT000547 and ZT000247. The third category was medium drought-resistant, which had a total of 7 germplasms. The fourth category was low drought-resistant, which had 13 germplasms, of which, ZT001698 and ZT001398 were highly drought-sensitive germplasms. By stepwise regression analysis, leaf dry weight and leaf saturated fresh weight were significantly correlated with D value. ZT000516 was a germplasm with strong drought resistance, and ZT001698 and ZT001398 were drought-sensitive germplasms. Leaf dry weight and leaf saturated fresh weight could be used as indexes for rapid and accurate identification of drought stress in sugar beet seedling stage.

  Effects of Nitrogen Application on Phosphorus Nutrition of Oil Flax GUO Lizhuo, YANG Bo, GAO Yuhong, NIU Junyi 2022, 38 (21):  24-31.  DOI: 10.11924/j.issn.1000-6850.casb2021-0024 Abstract + ( 147 )   HTML ( 1 )   PDF ( 1889KB )   ( 20 ) To explore the potential of nitrogen (N) fertilizer management in regulating phosphorus (P) nutrition of oil flax, two soil culture experiments were used, and the response of P accumulation and utilization of oil flax to N fertilizer amount, application period and ratio was studied. The results showed that N application significantly increased P accumulation in plants. Compared with no N fertilizer, 0.1 g N/kg soil and 0.2 g N/kg soil, all applied as basal fertilizer, increased P accumulation in mature plants by 24.83% and 34.23%, respectively. When N fertilizer of 0.2 g N/kg soil was set in the following five application modes: 100% basal fertilizer (F1), 2/3 basal fertilizer + 1/3 top dressing in budding period (F2), 1/2 basal fertilizer + 1/2 top dressing in budding period (F3), 1/6 basal fertilizer + 5/6 top dressing in fir-shaped period (F4), 1/6 basal fertilizer + 1/3 top dressing in fir-shaped period + 1/2 top dressing in budding period (F5), P accumulation in oil flax plants of F2, F3, F4 and F5 increased by 14.17%-32.60% (fir-shaped period), 9.32%-66.20% (budding period), 20.47%-36.35% (green fruit period) and 4.65%-31.04% (mature period), respectively, compared with that of F1, and the increasing range was in the order of F2, F3, F4 and F5. The N application mode of basal fertilizer combined with topdressing, accompanied by basal fertilizer ratio ≤1/2, effectively promoted P absorption, and the synergy effect of F3, F4 and F5 on P accumulation increased sequentially. N application synergistically improved P absorption efficiency and P fertilizer partial factor productivity. Compared with F1, F2, F3 and F4, F5 increased plant dry matter accumulation and grain yield by 7.89%-22.02% and 9.59%-26.71%, respectively, and improved P absorption efficiency and P fertilizer partial factor productivity by 10.58%-31.04%, and increased phosphorus absorption efficiency and phosphorus partial productivity by 10.58%-31.04% and 9.59%-26.71%, respectively, reduced P dry matter production efficiency by 2.42%-7.43%. The synergy effect existed in the absorption of N and P, and the greater the N fertilizer amount within a certain range, the greater the effect was. For the same amount of N fertilizer, basal fertilizer combined with topdressing played a better role in assisting P absorption than all N was used as basal fertilizer. N fertilizer of basal application less than 1/2 with top dressing of about 1/2 in budding period is a better N fertilizer management mode, which could not only promote oil flax growth, but also improve P absorption and P fertilizer partial factor productivity. However, this way could result in a lower P use efficiency for both dry matter production and grain yield.

  Effect of Different Nitrogen Fertilizer and Organic Fertilizer Application Rates on the Yield and Nutrient Distribution of Tomato NIE Dahang, CHEN Leilei, LIU Shuyan 2022, 38 (21):  32-35.  DOI: 10.11924/j.issn.1000-6850.casb2021-0865 Abstract + ( 234 )   HTML ( 1 )   PDF ( 1075KB )   ( 32 ) Crop biomass accumulation is closely related to nutrient accumulation, nutrient accumulation is the basis of biomass accumulation and crop yield formation. The migration, accumulation and distribution of nutrients in crops are the important process of crop nutrient utilization. A field trail in Yuanbaoshan District of Chifeng City was conducted to study the effect of different nitrogen and organic fertilizer application rates on the concentration and distribution of nutrients in tomato and the yield of tomato. The results showed that with the raise of organic fertilizer amount and decline of N fertilizer amount, the yield of tomato did not decline, the contents of NPK in tomato fruits increased. The ratio of NPK in the tomato fruits, stems and leaves increased too. It was found that the nitrogen fertilizer and organic fertilizer could increase the concentration of NPK nutrients in tomato fruits, and thus increasing the yield of tomato in this field trail. Adjusting the application amount of organic fertilizer and nitrogen fertilizer could effectively improve the nutrient ratio in tomato fruits to stems and leaves. Application of organic fertilizer could increase the absorption of nutrient elements in tomato fruits. The application of organic fertilizer partially replacing nitrogen fertilizer could not only promote the absorption and accumulation of NPK in tomato, but also improve the yield and quality of tomato fruits. It could also alleviate the environmental problems that were caused by large-scale application of nitrogen fertilizer. It indicated that under the local climate and soil conditions, replacing chemical fertilizer partially by organic fertilizer could improve tomato yield and nutrients’ content, and the quality of the environment.

  Effects of Bio-organic Fertilizer and Microbial Agents on Soil Fertility and Growth and Quality of Strawberry ZHU Shijun, WANG Lili, JIN Shuquan, ZHOU Jinbo, LU Xiaohong 2022, 38 (21):  36-43.  DOI: 10.11924/j.issn.1000-6850.casb2021-0869 Abstract + ( 189 )   HTML ( 3 )   PDF ( 2475KB )   ( 29 ) To explore the combined effect of bio-organic fertilizer and compound microbial agents on soil physical and chemical properties, and the growth and fruit quality of strawberry, strawberry ‘Red-Cheek’ was used as the material, and treatments were set up, including organic fertilizer as base fertilizer (T0), organic fertilizer as base fertilizer and microbial agents as topdressing (T1), bio-organic fertilizer as base fertilizer (T2), bio-organic fertilizer as base fertilizer and microbial agents as topdressing (T3) and inactivated bio-organic fertilizer as base fertilizer and inactivated microbial agents as topdressing (T4). The soil physical and chemical properties, and the growing status, yield and fruit quality of strawberries were investigated. The results showed that bio-organic fertilizer used as base fertilizer or microbial agents used as topdressing could significantly improve soil pH, increase soil organic matter and available nutrients, and decrease soil conductivity. It also had significant positive effects on vegetative growth and fruit quality of strawberry. The change rate of plant height, plant width and chlorophyll content from budding stage to maturity stage of T3 was 2.53%, 3.62% and 18.99% higher than those of T0, respectively. In addition, comparing the plant quality of T3 with that of T0, the biomass and dry matter weight of the aboveground part of T3 increased by 20.05% and 5.09% respectively, while those of the underground part increased by 2.69% and 5.05%. Furthermore, T3 increased the single fruit weight and fruit number, and the yield reached (30.10±3.87)t/hm2. T3 also had a significantly positive effect on fruit quality. The content of soluble solids increased by 2.08%-5.32% and that of titratable acid decreased by 5.15%-18.76%, and the VC content increased by 5.67%-10.22%. In summary, the combination of bio-organic fertilizer and microbial agents could have a significantly positive impact on soil fertility, and strawberry growth, yield and fruit quality. This study could provide a technical basis for facility strawberry cultivation.

  Different Nitrogen Application Rates: Effects on Net Carbon Effect of Summer Maize Farmland Ecosystem LU Chuang, HU Haitang, HUAI Heju, TIAN Yujie, SHI Jianan, LI Cunjun 2022, 38 (21):  44-50.  DOI: 10.11924/j.issn.1000-6850.casb2021-0854 Abstract + ( 181 )   HTML ( 1 )   PDF ( 3532KB )   ( 31 ) In order to explore nitrogen fertilizer management measures of low carbon production in north China, the typical summer maize field was used as the study object. The treatments included four nitrogen fertilizer rates: N0(0 kg/hm2), N1(100 kg/hm2), N2(150 kg/hm2) and N3(200 kg/hm2). The net carbon effect of different nitrogen application rates on summer maize farmland ecosystem was evaluated through statistical analysis of the test data of soil greenhouse gas emissions, indirect carbon emissions from agricultural inputs, and crop carbon sequestration. The results showed that soil CO2 and N2O emissions increased with the nitrogen application rate, while the CH4 uptake decreased with the nitrogen rate increase. The carbon equivalent of total soil emissions from treatment N1, N2 and N3 increased by 14.91%, 24.19%, and 29.67% compared with that of N0, respectively. Nitrogen fertilizer input, reaching 135.27-270.55 kg/hm2, contributed to a high proportion of the indirect emissions. Nitrogen application also promoted the accumulation of crop carbon sequestration, while the carbon content of net primary productivity of N0, N1, N2 and N3 reached 1965.56, 3125.68, 4345.55 and 4663.64 kg/hm2, respectively. The carbon flow in agricultural system indicated that all the treatments were carbon sinks. The net carbon effect of N0, N1, N2 and N3 was 258.33, 1034.99, 2032.82, and 2192.16 kg/hm2, respectively, and the carbon sustainable index reached 0.15, 0.50, 0.88 and 0.89, respectively. In summary, 200 kg/hm2 nitrogen application can be recommended as an appropriate input, because it deserves more carbon sequestration in exchange for less carbon consumption, showing a higher net carbon effect.

  Double Reduction of Chemical Fertilizer and Pesticide in Potato Production WANG Zhen, LIN Tuanrong, WANG Wei, WANG Yufeng, LUO Xiaobo, YAO Bin 2022, 38 (21):  51-57.  DOI: 10.11924/j.issn.1000-6850.casb2021-0867 Abstract + ( 248 )   HTML ( 2 )   PDF ( 1221KB )   ( 32 ) The purpose of this study is to explore the optimal green technology of double reduction of chemical fertilizer and pesticide in potato production, to improve potato yield and quality and guide the actual production. In this study, ‘Qingshu No. 9’ was used as experimental material. Four fertilizer treatments were designed, and two pesticides, A and B, were compared for each fertilizer treatment. The results showed that in treatment 2, compared with those of the control, potato quality was improved and the yield was increased by 6460.2 kg/hm2 by reducing chemical fertilizer application and increasing organic fertilizer application (750 kg/hm2). In treatment 3, potato quality was improved with the reduction of chemical fertilizer application and the increase of organic fertilizer application (600 kg/hm2) and microbial fertilizer (300 kg/hm2). In treatment 4, the reduction of chemical fertilizer application and the increase of organic fertilizer application (600 kg/hm2) and humic acid fertilizer (45 kg/hm2) could improve the potato quality and increase the yield by 32.24% compared with that of control. Pesticide treatment had no adverse effect on the yield and quality of potato tuber. This study showed that treatment 4 could increase potato tuber quantity and yield and improve quality by reducing the amount of chemical fertilizer and adding humic acid fertilizer, and the technology could be popularized in production.

  Effects of Tillage Methods on Soil Chemical Properties Under Straw Returning Condition QIE Tianzhen, LI Fu, LI Yahua, WANG Lifang, ZHANG Tingting, ZHANG Jiaqian, WANG Hongwei, ZHANG Dejian 2022, 38 (21):  58-69.  DOI: 10.11924/j.issn.1000-6850.casb2021-0747 Abstract + ( 198 )   HTML ( 1 )   PDF ( 1312KB )   ( 27 ) To solve the prominent problems such as the quality decline in black soil cultivated land and the environmental pollution caused by burning excess straw resources in the east foot of the Great Khingan Mountains, the conditions of straw returning to field were established combined with 7 tillage methods: deep ploughing + heavy harrow (SDH), subsoiling + heavy harrow (SSH), subsoiling and shallow ploughing + heavy harrow (SSS), heavy harrow (SH), rotary tillage (SRT), no tillage (SZT) and traditional tillage (CK). By studying the effects of different tillage methods on soil chemical properties under the condition of straw returning to field for two years, we obtained the following results: the soil organic matter increased rapidly in a short time after straw returning to field, and the organic matter level decreased again after a growth cycle. Compared with those under CK, the contents of available phosphorus and total potassium increased in 0-40 cm soil layer under SDH, SSH, SSS and SH in the first year; and the contents of alkali-hydrolyzable nitrogen, available potassium, total nitrogen and total phosphorus increased significantly under SDH, SSH and SSS. After harvest in the second year, SDH, SSH and SSS increased the contents of alkali-hydrolyzable nitrogen and total phosphorus in soil; SSH and SSS increased the contents of available phosphorus, available potassium and total nitrogen in 0-60 cm soil. Under the condition of straw returning, SSH and SSS could increase soil nutrient content significantly.

  Characteristics of Soil Selenium in Southwest Mountainous Area of Qingzhou, Shandong Province LIU Yang, ZHANG Hairui, SUN Zengbing, JIANG Bing, WANG Songtao 2022, 38 (21):  70-75.  DOI: 10.11924/j.issn.1000-6850.casb2021-0750 Abstract + ( 231 )   HTML ( 3 )   PDF ( 2410KB )   ( 21 ) Based on the data of geochemical survey and evaluation of land quality in Qingzhou of Weifang, the geochemical map of selenium was drawn. A total of 100 surface soil samples and 5 vertical soil profile samples were set up in the high selenium area to study the characteristics of soil selenium. The results show that: the average content of selenium in surface soil samples is 0.28 mg/kg, and the available selenium is 1.76%-14.21%, with an average of 5.70%. There is a negative correlation between pH and total selenium, but a positive correlation between pH and water soluble selenium. Phosphorus, nitrogen, organic matter and cadmium are positively correlated with total selenium and water soluble selenium. There is a positive correlation between total selenium and lead, zinc, nickel, arsenic and mercury. The main selenium speciation is strongly bound to organic matter and residue, and the speciation order is organic high bound state selenium in surface soil (38.22%)>residual state selenium (34.82%)>humic acid bound state selenium (21.05%)>carbonate bound state selenium (3.20%)>ion exchange state selenium (1.54%)>water soluble selenium (1.00%)>iron-manganese oxide selenium (0.17%). The enrichment of selenium in the study area is closely related to organic matter. In the vertical soil profile, the selenium content in the upper part is higher than that in the deep part.

  Cultivated Land Quality: Improving Technologies and Their Application LUO Mei, GUO Long, FEI Kun, ZHANG Tianen, LI Chen, MA Youhua 2022, 38 (21):  76-81.  DOI: 10.11924/j.issn.1000-6850.casb2021-0769 Abstract + ( 207 )   HTML ( 3 )   PDF ( 1177KB )   ( 41 ) Reasonably guiding farmers to adopt technologies that can improve the quality of cultivated land is very important to increase soil fertility, improve soil health, and promote high yield and efficiency of crops. This study analyzed the factors influencing the improvement of cultivated land quality, reviewed the improving technologies, including straw returning, green manure planting, deep ploughing and subsoiling, organic fertilizer applying, formula fertilization by soil testing, lateral deep fertilization for rice, soil conditioner applying and water-fertilizer integrating, and summarized the advantages and disadvantages of these technologies and their applied measures. At present, the research mainly focuses on the integrated application of the technologies for improving cultivated land quality, the differences of farmers’ adoption of various technologies, and the industrial application of modern information technology platform and equipment. It is proposed that we should improve the formulation of standards for multi-function technologies, strengthen the information technology such as high-scoring remote sensing to monitor and evaluate the quality of cultivated land, boost the utilization efficiency of cultivated land resources and perfect the ecological compensation mechanism for farmers.

  The Effect of Meteorological Factors on Sugarcane Yield and Research Progress of Environmental Interaction Genes LIAO Zhangbo, HE Yuanlan, MO Shendai 2022, 38 (21):  82-87.  DOI: 10.11924/j.issn.1000-6850.casb2021-0739 Abstract + ( 245 )   HTML ( 6 )   PDF ( 1113KB )   ( 38 ) There are many factors which can affect the yield of sugarcane, including the natural conditions, production conditions, cultivation system, cultivation and management technologies and variety characteristics, and the sugarcane yield is also closely related to meteorological factors. Rainfall has key influence on sugarcane at elongating and maturity stage, and has a positive correlation with the yield. The exploration and utilization of drought resistance genes can improve the drought resistance of sugarcane. Atmospheric relative humidity, temperature and light are important factors affecting sugarcane elongation, sugar content accumulation and yield per unit area. Under the influence of unique climate condition, the yield and sugar content of sugarcane are limited by factors such as drought, typhoon, flood, low temperature and high humidity and etc. Based on the analysis of the influence of meteorological factors of rainfall, humidity, sunshine on sugarcane yield, the research progress of sugarcane stress resistance genes were summarized. It was proposed that the development of molecular-marker assisted selective sugarcane breeding could play an important role in increasing sugarcane yield, and support the research on the relationship between agrometeorology and sugarcane production.

  Possible Impacts of Climate Change on the Risk of Apple Overwintering in China ZHANG Yong, QU Zhenjiang, LIU Yuefeng, LIU Lu, LI Yanli, PAN Yuying 2022, 38 (21):  88-96.  DOI: 10.11924/j.issn.1000-6850.casb2022-0141 Abstract + ( 230 )   HTML ( 1 )   PDF ( 2624KB )   ( 37 ) Safe overwintering is an important index to assess the possible impact of climate change on apple planting boundary and variety selection. Based on existing research, four agro-climatic indices were proposed to evaluate the effect of climate change on apple safe overwintering in China. The four agro-climatic indices, respectively, indicate the risk of damage to apple by early winter frost, the risk of the intensity and duration of low freezing temperature, the risk of damage by extreme low temperature, and the risk of damage to developing flower buds by late spring frost. We studied the variation trends and abrupt change characteristics of the four agro-climatic indices across main apple-producing regions of China, including the Loess Plateau, Bohai Bay, Old Course of the Yellow River, Southwest Highlands and Xinjiang, by using statistical methods and the ArcGIS analysis tools based on meteorological observational data from 1961 to 2015. The results showed that temperature significantly increased during the apple overwintering period in main apple-producing regions of China, while the number of annual accumulative frost days and the frequency of extreme low temperature events significantly decreased. The risk of damage to apple by early winter frost was increased due to the shortened interval between first frost and first low temperature in northern Bohai Bay, Old Course of the Yellow River and northern Xinjiang. The risk of the intensity and duration of low freezing temperature during the apple overwintering period decreased, so did the risk of damage by extreme low temperature, especially in high latitude regions. But the frequency of extreme low temperature events was uncertain in the Loess Plateau and Xinjiang producing regions. In addition, the risk of damage to developing apple flower buds by late spring frost increased in the Loess Plateau, Liaoning, western Sichuan and Xinjiang producing regions. To sum up, the risk of the intensity and duration of low freezing temperature and the risk of damage by extreme low temperature decreased, but the risk of damage to apple by early winter frost and the risk of damage to developing flower buds by late spring frost increased.

  Research Progress of Botanical Insecticides LI Zhuoli, XU Jianhui, LI Qidong, LIANG Yajie, ZHANG Lixiang 2022, 38 (21):  97-104.  DOI: 10.11924/j.issn.1000-6850.casb2021-0810 Abstract + ( 371 )   HTML ( 13 )   PDF ( 1219KB )   ( 83 ) Botanical insecticides are secondary metabolites produced by plants, which provide rich resources for research and development of insecticides because of their specific biological activities. They are alternatives to organic synthetic chemical pesticides. In this study, a brief history and current status of plant-based insecticides, and their active ingredients and modes of action were reviewed in detail, and the problems and development prospects of plant-based insecticide research were discussed. This study will provide reference for the development of more botanical insecticides.

  Control Efficacy of 7 Pre-emergence Herbicides Against Weeds in Winter Wheat Field WU Cuixia, XU Jiali, SONG Min, YANG Lina, ZHANG Tiantian, MA Chong 2022, 38 (21):  105-111.  DOI: 10.11924/j.issn.1000-6850.casb2021-0899 Abstract + ( 189 )   HTML ( 3 )   PDF ( 1270KB )   ( 36 ) In order to clarify the control efficacy of 7 pre-emergence herbicides against the annual weeds and their safety to winter wheat, the differences of control efficacy and safety of the herbicides between two modes of watering before and after herbicide application were compared in field according to Pesticide-Guidelines for the Field Efficacy Trails. The results showed that the total control efficacy under the watering mode after herbicide application was better than that under watering before herbicide application. Under the watering mode after herbicide application, the reduction in both weed number and biomass of Galium aparine, Descurainia Sophia and Alopecurus aequalis caused by flufenacet were higher than 95% at 150 days after treatment (DAT). Oxadiazon at 720 g active ingredient caused over 95% reduction in biomass of D. Sophia and A. aequalis, and over 85% reduction in biomass of G. aparine at 150 DAT. Based on the comprehensive analysis of safety, control efficacy and herbicide reduction, it is recommended to use flufenacet and oxadiazon for pre-emergence application in wheat field, which have ideal control efficacy with application once.

  Study on Dynamic Changes of AVR-Pia of Magnaporthe grisea in Southwestern Hubei HAN Xuchen, DONG Yan, HAN Haojie, TAN Yanping, LIU Xuequn, LIU Xinqiong, XU Xin, LI Kai, WANG Chuntai 2022, 38 (21):  112-121.  DOI: 10.11924/j.issn.1000-6850.casb2021-1080 Abstract + ( 183 )   HTML ( 3 )   PDF ( 4442KB )   ( 21 ) In order to understand the distribution and dynamic changes of AVR-Pia of Magnaporthe grisea in southwestern Hubei, 100 specific rice varieties were simultaneously planted in 9 locations in southwestern Hubei from 2017 to 2020, and the susceptible rice straws were collected to isolate monospore. We used the rice monogenic line IRBLa-A for pathogenicity identification, and designed specific primers for the avirulent gene AVR-Pia for PCR amplifying and sequence analyzing. The results showed that among the 661 isolates of Magnaporthe grisea isolated from 2017 to 2020, 49 isolates (7.4%) contained avirulent gene AVR-Pia. The frequencies of AVR-Pia were different significantly in different years and locations. From 2017 to 2020, the frequency of AVR-Pia was 7.5%, 16.0%, 3.1% and 5.0%, respectively. The location with the highest frequency of AVR-Pia was Yesanguan (15.8%), followed by Baiyang and Laifeng (both 14.6%), and no AVR-Pia was observed in Xianfeng, Jianshi and Taiping. The monogenic line IRBLa-A with Pia was resistant to 91 of the 661 isolates (13.8%). There were 49 isolates with 463 bp specific band of AVR-Pia, and no mutation was found in the CDS region through sequence analysis, but a base mutation G/T occurred at the 109 bp upstream of the start codon. Whether this point mution was related to expression needs further study. These results indicate that the avirulent gene AVR-Pia is less in southwestern Hubei, and the resistance gene Pia is not suitable for selective breeding as a major disease resistance gene in this region.

  Ecological Study of Rhizopus oryzae Causing Tobacco Leaf Mildew at the Curing Stage ZHU Ziping, HE Pengfei, LIU Yinglong, ZHAO Zhenglong, WU Yixin, HE Pengbo, CAI Yongzhan, MUNIR Shahzad, TIAN Yangyang, WANG Junwei, HE Yueqiu 2022, 38 (21):  122-128.  DOI: 10.11924/j.issn.1000-6850.casb2021-0722 Abstract + ( 142 )   HTML ( 3 )   PDF ( 2463KB )   ( 32 ) The aims are to study the ecological relationship between Rhizopus oryzae and tobacco leaf mildew (TLM) at the curing stage, and to provide a basis for making the disease-control strategy. The natural incidence rate of different parts of the petioles and stems were defined by tissue moisturizing method. The relationship between the incidence rate and water content was studied by inoculating the pathogen on petioles. The content of R. oryzae in the rhizosphere soil of tobacco fields and subsequent crops was determined by the dilution plate method. The results showed that the main fungus in tobacco rhizosphere soil was R. oryzae which caused TLM. Higher disease incidence rate appeared when the stem was close to petiole. Stem of continuously cropping tobacco plants displayed more incidence compared to that of new tobacco plants. The pathogen could easily invade the stem through infecting 1-14 nodes in the middle and lower parts of the plant. Tobacco petiole did not show any disease when the water content was lower than 40%, and the disease was most severe when the water content was 70%-80%. The number of R. oryzae in the root soil of continuously cropping tobacco plant was greater compared to newly planted soil. Root soil with black shank disease plants displayed more pathogen number compared to the one with healthy plants. R. oryzae was more abundant in the soil surrounding the roots of summer squash and cauliflower, while it was less in the soil surrounding the roots of peas and broad beans. This study highlights the significance of formulating control strategy for TLM at curing stage of tobacco.

  Quality Promotion and Disease Control Effects of Bacillus Strain R57 on Astragalus membranaceus var. mongholicus and Its Identification ZU Weixi, ZHAO Xiaoxia, GAO Fen 2022, 38 (21):  129-135.  DOI: 10.11924/j.issn.1000-6850.casb2022-0190 Abstract + ( 209 )   HTML ( 2 )   PDF ( 1706KB )   ( 23 ) The study aims to explore the quality promotion and disease control effects of strain R57 on root rot of Astragalus membranaceus var. mongholicus (AMM), and identify its classification status. The antifungal activity of bacteria-free filtrate was determined by Oxford cup method, the control effect in detached roots was evaluated by seedling root dipping method, and the control effect in potted plants was tested by conventional root-irrigation method. The changes of main active components in roots of AMM irrigated with the fermentation broth of strain R57 were tested by HPLC-UV-ELSD. The strain R57 was identified by means of morphology, physio-biochemical characteristics and 16S rDNA sequence analysis. In the inhibition test in vitro, the diameters of inhibition zone of R57 bacteria-free filtrate to F. solani and F. acuminatum were (18.02 ±1.71) mm and (19.96±2.42) mm, respectively. In the detached roots test, the therapeutic treatments using R57 bacteria-free filtrate showed significant control effect on F. solani and F. acuminatum infection on both 7 d and 15 d; the protective treatments showed significant control effect on F. solani infection on 7 d and on F. acuminatum infection on 15 d, respectively; the antagonistic treatments had obvious control effect on F. solani infection only on 7 d. In the pot experiment, the protective effects of the fermentation broth of strain R57 on the root rot caused by F. solani and F. acuminatum were 61.27%±4.89% and 64.33%±8.25%, respectively; no significant therapeutic effect on root rot was observed for all the treatments. The fermentation broth of strain R57 had obvious promotion effect on the accumulation of two main active components in AMM: calycosin-7-O-β-D-glucoside and ononin. The strain R57 was identified as Bacillus subtilis. The Bacillus subtilis strain R57 can reduce the incidence of root rot disease and promote the accumulation of main flavonoids active components in the AMM root; therefore, it can be further studied as a muti-functional strain for the development of microbial agent.

  Quality Control Technology of Green Tea Taste: Research Progress LIAO Jun, WANG Yejun, SU Youjian, FANG Hongsheng, ZHANG Yongli, SUN Yulong, FANG Yage 2022, 38 (21):  136-140.  DOI: 10.11924/j.issn.1000-6850.casb2021-0900 Abstract + ( 184 )   HTML ( 2 )   PDF ( 1105KB )   ( 33 ) Green tea is the main consumption tea in China, and taste is the core indicator of its quality evaluation. Previous studies have shown that tea varieties, cultivation environment, processing technology, storage conditions and other factors affect the content and proportion of main taste components in green tea, thereby having impacts on its quality. This article reviewed the influence of these critical factors on the taste quality of green tea, and discussed the development trend of taste quality control technology of green tea. The study could provide reference for improving the taste quality of green tea.

  Study on Landscape Change of Rural Settlements in Mountainous Area of Northwest Shanxi Province—A Case of Dashuikou Village LIU Xin, JIA Ningfeng 2022, 38 (21):  141-149.  DOI: 10.11924/j.issn.1000-6850.casb2022-0211 Abstract + ( 173 )   HTML ( 2 )   PDF ( 3180KB )   ( 28 ) With the proposing of the Rural Revitalization Strategy, rural development has become a key part of the country’s overall development. However, in China’s less developed areas, most traditional villages still have problems such as delayed development, chaotic settlement structure and fragile ecological environment, which are the key problems to be solved in rural development. Based on the remote sensing images of 1980, 1990, 2008 and 2020, this paper took Dashuikou village in Ningwu County of northwest Shanxi Province as the research object, established a database and analyzed the village’s landscape change characteristics in the past 40 years by using methods of participant observation and GIS spatial analysis, and the study will provide reference for the traditional rural development in Shanxi Province and even the whole country. The main results showed that: (1) the scale of private space of the settlements gradually increased in the past 40 year, and so did the patch number and patch area, the shape character gradually became simple, and the boundary shape was more regular; (2) the agricultural production land in the production space of the settlements was reduced, which was mainly converted into woodland and residential land, and the increase of industrial and mining land mainly occupied agricultural land; (3) the public space did not developed with the development of the settlements; instead, its layout was gradually decreased and abandoned; only some infrastructures were improved slightly. This study is expected to provide more detailed information and a theoretical basis for future village planning and management.

  The Realistic Dilemma and Path Choice of the High-quality Development of Family Farms in Shandong Province JIA Zhen, ZHANG Yi 2022, 38 (21):  150-157.  DOI: 10.11924/j.issn.1000-6850.casb2021-0845 Abstract + ( 211 )   HTML ( 1 )   PDF ( 2039KB )   ( 56 ) Family farm is an important carrier and basic support for realizing agricultural modernization on the basis of “small farmers in big countries”. In recent years, family farms in Shandong Province have developed rapidly but the overall development quality is not high. Under the development requirements of the new economic period, it is of great significance to comprehensively promote the transformation of family farms to high-quality development. Based on the sorting out of family farm support policies in Shandong Province, this article divided the development of family farms by stages, and combines relevant statistical data to analyze the development status of family farms in Shandong, summarized the prominent problems facing the current high-quality development of family farms. Therefore, it is necessary to choose perfect land circulation system, promote the rural talent incentive training mechanism, provide diversified government subsidy support, increase government service supply, and promote the development of agricultural socialized service system, comprehensively promote the transformation and upgrading of family farms from incremental to quality improvement.

  The Development Route of Efficient Agriculture with Tropical Characteristics in Hainan Free Trade Port WANG Wei 2022, 38 (21):  158-164.  DOI: 10.11924/j.issn.1000-6850.casb2022-0447 Abstract + ( 161 )   HTML ( 3 )   PDF ( 2188KB )   ( 22 ) As the only free trade port covering a whole island in the world, Hainan requires particular attention concerning the Sannong issues (namely, agriculture, rural community and farmers). In recent years, agriculture in Hainan has maintained a good growth momentum, but there are still problems such as insufficient scale, intensification, standardization, branding, marketization and etc. The regression analysis of panel data shows that the impact of the agricultural industry on farmers’ income is significantly negative. The study proposes some suggestions on agriculture development in Hainan, including revitalizing the abandoned rural land through comprehensive land consolidation for intensive and large-scale development, to uphold the principle of food security; stabilizing rubber plantation and production and developing under-forest economy, to diversify the sources of farmers’ income; developing market oriented agriculture with regional characteristics through high-level opening up, to promote Hainan’s agriculture towards standardization and branding; and accelerating the establishment of National Tropical Agricultural Science Center to improve the transformation of agricultural scientific and technological achievements.