Table of Content

15 July 2021, Volume 23 Issue 7

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Development Status of Wheat Industry in China and International Experience for Reference

JIANG Yun, ZHANG Lili, XUE Ping, WANG Xiudong

2021, 23(7):  1-10.  DOI: 10.13304/j.nykjdb.2021.0412

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As an important food crop, wheat plays a pivotal role in both grain structure and national economy. Firstly, this paper analyzed the development of Chinas wheat industry from several aspects, including the fluctuation of wheat planting area and yield, evolution of wheat production area distribution, evolution of wheat varieties, wheat supply and demand situation etc.. Then combined with the development characteristics of the wheat industry in developed countries such as the United States, Australia, France, etc., and summarized the advanced experience in the development of the wheat industry in these countries. The results showed that the total supply of wheat in China was basically sufficient. However, there were some problems in Chinas wheat industry, such as small and scattered wheat planting, common multi\|variety hybrids, unreasonable product structure, imperfect industrial system and social service system. From the experience of developed countries, Chinas wheat industry should form a centralized continuous planting, implement separate planting and harvesting of different varieties of wheat for storage, guide the standardized planting of wheat based on demand, improve the agricultural socialized service system.

Review, Status and Measures of Xinjiang Machine-picked Cotton

XIN Minghua§, WANG Zhanbiao§, HAN Yingchun, FAN Zhengyi, FENG Lu, YANG Beifang, LI Xiaofei, WANG Guoping, LEI Yaping, XING Fangfang, XIONG Shiwu, LI Yabing

2021, 23(7):  11-20.  DOI: 10.13304/j.nykjdb.2020.0030

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Cotton is a pillar industry in Xinjiang and has an important strategic position for Chinas economic development, which directly related to the implementation of Xinjiangs rural revitalization strategy and the enthusiasm of cotton farmers. In recent years, the large-scale popularization and application of machine-picked cotton has greatly improved the efficiency of picking cotton and alleviated the problem of labor shortage, but the profit of cotton farmers has not increased due to the price of cotton hovering at a low level. By reviewing the development process of Xinjiang machine-picked cotton, the development status of Xinjiang machine-picked cotton was briefly described, and the problems and development suggestions of Xinjiang machine-picked cotton development were put forward. It should aim to provide solutions for the development of Xinjiangs machine-picked cotton industry and promote Xinjiang sustainable development of the cotton industry.

LI Junjie, DU Pufang, SHI Tingrui, HOU Peijia, CHAI Xinyu, ZHAO Rui, WANG Yu, LI Hongxia*

LI Junjie, DU Pufang, SHI Tingrui, HOU Peijia, CHAI Xinyu, ZHAO Rui, WANG Yu, LI Hongxia

2021, 23(7):  21-32.  DOI: 10.13304/j.nykjdb.2020.0927

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Nitrogen is an important nutrient element and restricts wheat growth and economic yield,  so screening and breeding low nitrogen tolerant wheat varieties is an effective way to improve nitrogen utilization rate and reduce production cost. In this study, 118 wheat varieties were grown in low nitrogen (0.1 mmol·L^-1) and normal nitrogen (5 mmol·L^-1)  conditions using hydroponic methods. Nitrogen efficiency of plants was measured based on 7 indicators about root dry weight, straw dry weight,  root/shoot ratio, plant dry weight, maximum root length, primary root number and secondary primary root. The low nitrogen tolerance of wheat varieties was evaluated by using fuzzy membership function method, principal component analysis and cluster analysis. The results showed that the root dry weight, root/shoot ratio and primary root number of wheat seedlings significantly increased, the stem and leaf dry weight, plant dry weight and maximum root length decreased in different degrees under low nitrogen stress, and the 7 seedling traits were significantly different at the two nitrogen levels. Three principal components were extracted by principal component analysis, and the contribution rate was 43.575%, 22.904% and 17.873%, respectively. The cumulative contribution rate reached to 84.351%. 118 wheat varieties were divided into 5 categories (strong resistance to low nitrogen, resistance to low nitrogen, medium resistance to low nitrogen, nitrogen sensitive, and nitrogen highly sensitive) according to the D value of comprehensive evaluation of low nitrogen tolerance. Qida 195, Jinfeng 7183 and Tianmin 198 were identified as low nitrogen tolerant wheat varieties. Two varieties (Shannong 0917 and Lumai 8) with relatively strong low nitrogen tolerance were screened. There were some obviously differences in the low nitrogen tolerance mechanisms of different wheat varieties. The research results provided theoretical and material basis for breeding of wheat varieties with low nitrogen resistance.

Antioxidative Characteristics Study of Nitrogen in Alleviating Premature Senescence of Spring Wheat at High Temperature after Anthesis

JIAN Tiancai, KANG Jianhong, WU Hongliang, LIU Genhong, GAO Di, MA Xueying, LI Xin

2021, 23(7):  33-44.  DOI: 10.13304/j.nykjdb.2020.0374

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In order to study the response mechanism of nitrogen fertilizer to the antioxidant properties of spring wheat under high temperature stress after anthesis and  clarify the physiological mechanism and operational mechanism of nitrogen to alleviate the harm of high temperature, in 2019, the split plot design was adopted with five nitrogen applications including 0 (N0), 75 (N1), 150 (N2), 225 (N3) and 300 (N4)kg·hm^-2 (primary zone) and two temperatures including (25±2)℃(CK) and (35±2)℃(HT) (secondary zone). Carotenoid content, superoxide dismutase (SOD) activity, peroxidase dismutase (POD) activity, catalase dismutase (CAT) activity, malondialdehyde (MDA) content, proline (Pro) content, superoxide anion radical (O^-₂·) content in flag leaf of spring wheat and their relationship with yield were analyzed. The results showed that the application of nitrogen fertilizer could significantly increase the contents of carotenoid, Pro and nitrogen in flag leaf, and improve the activities of SOD, POD, CAT and other enzymes, with the best effect of N3 treatment. Compared with CK, the content of carotenoids and the activities of SOD, POD and CAT in flag leaves  decreased after high temperature stress, and the degree of decrease was the smallest under N3. In addition, the contents of MDA and O^-₂· in flag leaf  increased significantly after high-temperature stress compared with CK, with the largest increase under the N0 treatment and the smallest increase under the N3 treatment. With the increase of nitrogen application, the 1 000-grain weight and yield of spring wheat showed a trend of increasing first and then decreasing. The yield of N3 treatment was the highest, 8.64 (CK) and 8.09 (HT) t·hm^-2, respectively. Compared with CK, the yields after high-temperature stress was decreased significantly, with a decrease from 7.81% to 33.71%. In conclusion, the carotenoid content and activities of  SOD, POD and CAT  in flag leaf under high-temperature stress  significantly decreased, and the MDA and O-2· contents  increased significantly, which led to an increase in the degree of membrane lipid peroxidation and premature aging. A suitable amount of nitrogen application (225 kg·hm^-2) could effectively resist high temperature stress and alleviate premature aging by maintaining  high activities (SOD, POD and CAT) and contents of Pro and carotenoid, and reducing the contents of MDA and O^-₂·, which could provide theoretical basis and technical support for high and stable yield of spring wheat.

Effect of Planting Density on the Expression of Insecticidal Protein and Nitrogen Metabolism in the Fiber of Bt Transgenic Cotton

CHEN Yuan, LIU Zhenyu, ZHOU Mingyuan, ZHANG Chenxia, TIAN Qiaofeng, ZHANG Zhongning, ZHANG Xiang, CHEN Dehua

2021, 23(7):  45-53.  DOI: 10.13304/j.nykjdb.2020.0351

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In order to study the effect of planting density on the expression of insecticidal protein in the fiber of Bt transgenic cotton and corresponding nitrogen metabolism in this process, the Bt transgenic varieties including Sikang1 (conventional variety) and Sikang3 (hybrid) were used as experimental materials, five different of planting densities (1.5×10⁴, 3.0×10⁴, 4.5×10⁴, 6.0×10⁴, 7.5×10⁴ plants·hm^-2) were set  for studying the difference of Br protein expressions and nitrogen metabolism. The results showed that the expression levels of Bt protein in cotton fibers were enhanced as planting density increased. Correlation analysis showed that the boll number per plant, boll volume, and boll dry weight were all negatively correlated with the expression level of Bt protein. The related parameters in nitrogen metabolism were altered with planting density. The content of soluble protein, the activities of glutamic-pyruvic transaminase (GPT) and glutamic oxaloacetic transaminase (GOT) were increased under high planting density, but the content of free amino acid, the activities of protease and peptidase were all decreased under high planting density. The expression level of Bt protein was positively correlated with the content of  soluble protein and the activities of GPT and GOT, but negatively correlated with the content of free amino acid and the activities of protease and peptidase. In conclusion, with planting density increased, the boll growth was reduced and the expression level of Bt protein was elevated, while the expression level of Bt protein was closely related to nitrogen metabolism. Thus, in order to guarantee the insecticidal resistance, it was important to balance the boll development and the expression level of Bt protein, which should promote protein synthesis ability in cotton production.

Genetic Diversity Analysis of Indian Chickpea (Cicer arietinum L.) Resources and Screening of Excellent Germplasm

YU Haitian, LYU Meiyuan, WAN Shuwei, YANG Feng, HU Chaoqin, YANG Xin, ZHANG Xiaoyan, WANG Yubao, HE Chunhua, LIN Deming, WANG Liping

2021, 23(7):  54-64.  DOI: 10.13304/j.nykjdb.2020.0861

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In order to study the genetic diversity of agronomic traits of Indian chickpea resources, by diversity analysis and comprehensive evaluation, genetic diversity analysis, cluster analysis, principal component analysis and comprehensive D value, 12 agronomic traits of 181 chickpea resources were analyzed to select the major agronomic traits, which had significant effect on comprehensive evaluation and excellent resources which had comprehensive well performance. The results showed that the coefficient of variation of 12 agronomic traits were 7.47% (days from sowing to flowering period, DSFP) to 85.26% (number of pods no seeds per plant, NPNS), among which HSW (hundred seeds weight), NB (number of branches), NBP (number of branches with pods), NPSP (number of pods with seeds per plant), DFFP (days from first flower to flowering period), YPP(yield per plot), YH (yield per hectare) and NPNS were all higher than 30%, indicating that these traits had great potential for improvement. The Shannon-Wiener analysis showed that diversity index of 12 agronomic traits were 1.750 9 (YP) to 2.053 5 (number of seeds per pod, NSPP), among which the NSPP, PH (plant height), NBP and DSFF (days from sowing to first flower) were higher than 2.000 0, and all traits were higher than 1.700 0, indicating that all the index of 12 traits distributed well. Cluster analysis showed that when European distance was 3.41, 181 resources were clustered into nine groups with different number of resources.Excepting group Ⅸ, all groups had different advantages. Meanwhile, four traits including NPSP, DSFF, PH, NB had significant effects on. And 31 germplasm resources were selected with better comprehensive characteristics by D value, which provided  theoretical basis and excellent resources for innovative utilization of chickpea in China.





Effects of CaCl2 on Seed Germination and Seedling Physiological Characteristics of Schizonepeta tenuifolia Briq. under Salt Stress

ZHANG Shengzhen, MA Yanzhi

2021, 23(7):  65-71.  DOI: 10.13304/j.nykjdb.2020.0900

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In order to study the effects of calcium chloride soaking seeds on the germination and physiological characteristics of Schizonepeta tenuifolia Briq. under salt stress, the seeds  were soaked in different concentrations of CaCl₂ (2.5, 5, 10, 20 and 40 mmol·L^-1). The germinations of seed and physiological characteristics of  seedling were measured in 150 mmol·L^-1 NaCl solution. The results showed that the seed germination and seedling growth of Schizonepeta tenuifolia Briq. were obviously inhibited under 150 mmol·L^-1 NaCl stress. Compared with salt stress treatment without CaCl2, soaking seeds of CaCl2 could improve the germination rate, germination potential, germination index, vigor index of seeds and the height, root length, fresh weight of seedlings. And the activities of superoxide dismutase, peroxidase and catalase of seedlings were increased, while the contents of malonaldehyde were decreased after CaCl₂ soaking. In addition, the contents of proline and soluble protein of seedlings were decreased after CaCl₂ soaking. These results indicated that CaCl₂ soaking could alleviate the damage under salt stress, and the effect of the treatment with 20 mmol·L-1 CaCl₂ was the best, which provided theoretical basis and technical reference for the cultivation and production of Schizonepeta tenuifolia Briq. in saline land area.





Nitrate Assimilation Gene Distribution and Pathway-specific Regulation in Nitrogen-fixing Pseudomonas stutzeri A1501

HUANG Liling, LI Yun, WANG Shanshan, LU Chao, YANG Zhimin, LIN Min, YAN Yongliang, CHEN Ming, ZHANG Wei, WANG Jin, ZHOU Zhengfu, KE Xiubin, ZHAN Yuhua, LU Wei

2021, 23(7):  72-81.  DOI: 10.13304/j.nykjdb.2021.0329

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Nitrogen-fixing Pseudomonas stutzeri A1501 can grow with nitrate/nitrite as the sole nitrogen source under aerobic conditions, suggesting that the strain has a nitrate/nitrite system in addition to nitrogen fixation and denitrification. In order to further clarify the metabolic mechanism of nitrate assimilation, bioinformatics method was used to analyze the composition and distribution of genes related to nitrate assimilation, and the pathway-specific control of nitrate assimilation was preliminarily studied. The results indicated that there were two nitrate assimilation gene clusters, nasST-nasA-nirBDnasBcobA and nasR-nasFED, distributed in different parts of the genome. In the first gene cluster, nasS-nasT encoded two-component regulatory system based on nitrate/nitrite sensing and transcription anti-termination, nasA encoded NarK/NasA family nitrate transporter, nirBD encoded nitrite reductase, nasB encoded assimilatory nitrate reductase, and cobA encodes uroporphyrin-Ⅲ C-methyltransferase involved in the synthesis of sirohaem. In the second gene cluster, nasR encoded a single-component transcription anti-terminator and nasFED encoded an ATP-dependent nitrate/nitrite transporter. Nitrate/nitrite reductase gene transcription was regulated by NasS-NasT, and nitrate/nitrite transporter gene transcription was regulated by NasR.

Design and Experiment of Devices to Separate Membrane from Soil for Mechanical Recycle of Farmland Residual Membrane

HU Guangfa, QUAN Lazhen, ZOU Yunmei, SHEN Hui, KUANG Xinpeng, HUANG Conghui

2021, 23(7):  82-92.  DOI: 10.13304/j.nykjdb.2020.1062

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In the operation process of farmland residual membrane recycles in southern China, the residual membrane is very easily entangled on the machines due to the strong soil viscosity, which will affect the normal operation of the farm machines. To deal with this problem, a device to separate membrane from soil was designed in this paper. The device was mainly composed of elastic tooth to pick up the membrane, roller and cam pressing plate mechanism. It could remove the soil on the surface of the residual membrane in the process of membrane picking, and remove the soil under the residual membrane in the process of sending the membrane. Through the test and analysis, the main factors that affect the membrane soil separation were the forward speed of the machine, the rotating speed of the picking membrane and the installation angle of the roller. So taking above three factors as the test factors, and the soil content and membrane wrapping rate as the response values, three factors and three levels response surface test was conducted. In the process of the experiment, the regression model of each factor between membrane wrapping rate and soil content was established by using Desige-Expert software to deal with the data. In addition, the significance of each factor to the response value was analyzed. The results showed that the order of significance of each factor to soil content was as follows: machine forward speed > membrane pick-up speed > drum installation angle; the order of significance of membrane wrapping rate was: roller installation angle > membrane pick-up rotation. Meanwhile, by the optimization of the experiment factors, the best combination of the factors was obtained as follows: the forward speed of the machine was 1.12 m·s^-1, the membrane picking speed was 92.00 r·min-1, the installation angle of the roller was 17.00°, and the soil content was 13.00%, the membrane wrapping rate was 1.70%. Setting the above optimal working parameters combination through the soil bin simulation test,  the soil content was 13.45%, the membrane wrapping rate was 1.78%, and the relative error between the test verification results and the model optimization results was less than 5%. The device solved the problems of difficult membrane soil separation and high residual membrane rate in southern cohesive soil, and provided reference for the design and optimization of membrane soil separation device and residual membrane recovery machine.

Rape Variety Identification Based on Canopy Spectral Parameters

LUO Lisha, LIAO Guiping, LIU Fan, GUAN Chunyun

2021, 23(7):  93-106.  DOI: 10.13304/j.nykjdb.2020.1005

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Hyperspectral is widely used in agriculture, and   it provides certain technical support for the classification and identification of crop varieties due to fast, efficient, accurate and non-destructive characteristics. This paper collected canopy reflectance spectra data of 11 rapeseed varieties in the pre-seedling and late seedling stages, using a total of 23 characteristic parameters in 6 aspects of hyperspectral position, amplitude, area, width, reflectance and vegetation index as indicators to measure the contribution rate of the characteristic parameters and the significance of the analysis of variance. Based on this, the effect of distinguishing and identifying on different varieties of rape was analyzed. The results showed that: from the view of contribution rate, different types of hyperspectral characteristic parameters had different ability to distinguish rape varieties, the amplitude parameter had the strongest ability to distinguish rape varieties, and the width parameter had the weakest ability to distinguish rape varieties. The overall effect from strong to weak was: amplitude parameter>area parameter>reflectance parameter>vegetation index parameter>position parameter>width parameter; from the perspective of analysis of variance, the effects of distinguishing rape varieties in different periods were different. Among them, the comprehensive effect of identifying rape varieties with vegetation index parameters was the best. The identification effect in the late seedling stage was better than pre-seedling stage, the three characteristic parameters of D_r, SD_r/SD_{b and} (SD_r-SD_y)/(SD_r+SD_y) were the best in the multiple comparison analysis of variance, which could clearly distinguish 6 varieties. Canopy spectral characteristic parameters at seedling stage could classify and identify rape varieties. The research results laid the foundation for the rapid classification and identification of crops and the rational formulation of the planting area and spatial distribution of crops.

Simulation Analysis of Pneumatic Conveying Device of Air-suction Jujube Picker Based on CFD-EDM Coupling

ZHANG Fengkui, ZHANG Hong, LAN Haipeng, YU Fufeng, LI Zhongjie, LI Ping

2021, 23(7):  107-116.  DOI: 10.13304/j.nykjdb.2020.0598

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In order to clarify the pneumatic conveying motion characteristics of the jujube in the pneumatic conveying device of the pneumatic suction jujube picker, the gas-solid two-phase flow in the pneumatic conveying device was simulated. Based on the gas-solid two-phase flow theory, a computational fluid model and a discrete element model were established, respectively. By computational fluid dynamics and discrete element method (CFD-EDM), the movement state, particle distribution and airflow field distribution of the inlet to the outlet of the device were simulated and analyzed, and the design of the cleaning box and the experimental verification were explored through simulation optimization experiments. The results showed that: ① most of the jujubes were discharged after hitting the grid and board, and a few jujubes remained in the box, and a small part was stuck or passed through the jujube grid. ② The separation chamber and the settlement chamber of the box  easily generated vortex phenomenon and increased energy loss. The average flow velocity through the grid was 17.85 m·s^-1 and the airflow trajectory was chaotic. ③After optimization, the airflow trajectory inside the box moved along the path of the box and reduces the occurrence of vortex phenomenon. The average flow velocity decreased to 6 m·s-1 to reduce the damage caused by the excessive kinetic energy of the jujube. ④The optimal structure of the corner diameter parameter of the box was 200 mm and the box inlet height was 65 mm. ⑤It was obtained through prototype test. Test results was closed to the simulation result. The above results showed that it was feasible to use the CFD-EDM two-phase flow coupling technology to simulate the pneumatic conveying device of the air-suction red date picker, and to optimize the box structure to shorten the conveying time of jujube in the pneumatic conveying device and improve the working efficiency of the prototype. The research results  provided reference for the simulation and optimization design of pneumatic conveying device of pneumatic jujube harvester.

Qualitative Study on Phosphorus Content in Rubber Leaves Based on AE-FFNN Neural Network

YE Linwei, TANG Rongnian, LI Chuang

2021, 23(7):  117-124.  DOI: 10.13304/j.nykjdb.2020.0726

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Phosphorus is very important for the growth and development of rubber trees. There are many studies on the rapid non-destructive detection of nitrogen, phosphorus and potassium content of rubber trees based on near infrared spectroscopy, but the detection effect of phosphorus content is far less than that of nitrogen and potassium. Based on near infrared hyperspectral technology, combined with nonlinear feature extraction method and modeling algorithm, the rapid non-destructive detection of phosphorus content in rubber tree was realized. The near-infrared hyperspectral data of rubber leaves were taken as the analysis object, and the feature extraction idea of neural network nonlinear transformation was used to construct a model fusing autoencoder and feedforward neural network (AE-FFNN). The nonlinear spectral feature information of rubber leaves was extracted by autoencoder, and the model was established by using feedforward neural network to deal with classification tasks with different levels of fineness to realize the qualitative analysis of phosphorus content in rubber leaves. The results showed that AE-FFNN model could effectively extract spectral nonlinear features and compress the number of features. 31 features were extracted by this method, and the accuracy of qualitative analysis model was improved, which reached to 91.10%. Compared with the machine learning model widely used in the field of spectral detection, the performance of the AE-FFNN model was greatly improved. The model could be used not only for qualitative analysis of phosphorus content in rubber leaves, but also for quantitative study of phosphorus content.

Thermal Comfort Evaluation of Pigsty and CFD Simulation of Wet Curtain in Summer

GAO Yun, WANG Yu, LU Sidi, LEI Minggang, LUO Junjie, LI Xuan,

2021, 23(7):  125-135.  DOI: 10.13304/j.nykjdb.2019.1033

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The factors affected the thermal comfort of pig house include temperature, humidity, wind speed and thermal radiation. The thermal comfort of pig body is coused by these factors and the comprehensive effect of pig metabolism. The traditional temperature and humidity index can not accurately express the thermal comfort of pigs. In this paper, based on the index of predicted mean vote (PMV), the index of pig PMV was proposed by analogy. Using computational fluid dynamics (CFD), the temperature and humidity model field of pig house under the action of summer wet curtain was established, and the PMV field simulation model of pig body was calculated on this basis. The model data was compared with the data of wireless sensor network and the error fluctuation was less than 6%. Under the action of wet curtain in summer, the temperature field in the simulated pig house decreased about 4 ℃ on the whole, the wind speed showed low in the middle and high schools on both sides, and there was a certain area of air flow dead zone near the wall and the corner of the pig house. The fluctuation range of PMV index under the action of wet curtain was -0.5~+0.5, which belonged to the comfortable index range. This method could obtain the accurate field distribution of thermal comfort in the living area of pigsty, and provided  theoretical basis for the optimization of environmental control of pigsty.

Identification of Two Strains of Bacillus amyloliquefaciens and Their Antagonistic Activity to Carbendazim-Resistant Botryodiplodia theobromae

DONG Guoran, SHA Litang, ZHOU Chuang, FU Kexin, YANG Ye

2021, 23(7):  136-144.  DOI: 10.13304/j.nykjdb.2020.0369

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Mango stem-end rot disease is mainly caused by Botryodiplodia theobromae in Hainan. Two antagonistic bacteria strains (HBW and HBR) were isolated from the mango fruits in Hainan Province. They were identified according to morphological observation, physiological and biochemical characteristics, and consequences of 16S rRNA homologous analysis. The antagonistic activities of the bacterial suspensions in the two bacteria strains were characterized using in vitro antagonistic tests. The inhibiting effect on B. theobromae differing in carbendazim resistance were tested by the bacterial suspension and cell-free culture filtrate. The results showed that two strains of HBW and HBR were identified as Bacillus amyloliquefaciens. They exhibited higher antifungal activity, which strongly inhibited the growth of many plant pathogenic fungi. The bacterial suspension and diluted culture filtrate were effective to carbendazim-resistant and -sensitive strains of B. theobromae. The diluted culture filtrates had higher inhibiting effect compared with the bacterial suspension, and the highest inhibition rate of 20% culture filtrate of the HBW strain reached 100%. The two strains of B. amyloliquefaciens (HBW and HBR) had good potential for development and application.

Identification and Biological Characteristics of the Pathogen Causing Pink Disease of Chestnut

ZHANG Nana§, LI Shuangmin§, WEN Xiaolei, FENG Lina, WANG Junfeng, YANG Wenjie, HUO Jiahuan, LAN Shuhui, SUN Weiming, QI Huixia

2021, 23(7):  145-152.  DOI: 10.13304/j.nykjdb.2020.0747

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In order to clarify the pathogen and biological characteristics of chestnut pink disease, tissue isolation method was used to isolate and purify the pathogen; Koch′s rules, morphological characteristics and molecular biotechnology were used to identify the pathogen; and the effects of different temperature, humidity, medium, carbon and nitrogen sources, light and pH on the growth and sporulation of the pathogen were studied. On PDA medium,the mycelium of the pathogen was white at the initial stage of growth, while at the late stage,the central part of mycelium was orange pink, and the edge was light white with concentric annulation. The conidia were colorless and transparent, single cell, pear shape, smooth surface, with 0～1 diaphragma, without mediastinum, and constricted at the septum. The sequence similarity between its sequence of the pathogen and that of Trichoderma roseum (MN882763) was 100%. According to the morphological characteristics and molecular biotechnology, the pathogen of chestnut pink disease was Trichothecium roseum. The optimum growth conditions was gum acacia powder as carbon source, peptone as nitrogen source was, pH 8,temperature 25 ℃， PDA medium and 12 h light and dark alternate. The optimum conditions for sporulation was lactose as carbon source, peptone as nitrogen source, pH 7, temperature 25 ℃, beef extract peptone medium and 12 h light and dark alternate. Above results provided scientific basis for the control of the disease.

Effects of Reduction Application of Polyurethane Coated Urea on Growth, Yield and Economic Benefit of Double-cropping Early Rice

ZHOU Xuan, KANG Xingrong, PENG Jianwei, YANG Xiangdong, ZHONG Xuemei, HU Wenfeng, LONG Junyou

2021, 23(7):  153-161.  DOI: 10.13304/j.nykjdb.2020.0094

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In order to explore the effect of reduction application of controlled-release urea on the yield of early-rice and its reduction potential in Southern China under the condition of one-time fertilization, a plot experiment was conducted in Dongting Lake, Hunan Province, for two consecutive years from 2018 to 2019. Four treatments including no nitrogen fertilizer (CK), conventional fertilization (CU), polyurethane coated urea (PuCU) and 80% polyurethane coated urea nitrogen (0.8PuCU) were set up  to study the effect of reduction application of polyurethane coated urea on the yield, yield components, growth and economic benefit of early-rice. The results showed that different application treatments of controlled-release urea had significant (P<0.05) or extremely significant (P<0.01) effects on the yield, yield components and economic benefits of double-cropping early-rice. Compared with CU treatment, the yield and economic benefit of double-cropping early-rice in PuCU treatment  increased by 11.99% and 12.99%, respectively, and the effective panicle number, total spikelet number and total grain number  increased by 5.73%, 11.67% and 16.22%, respectively; the yield and economic benefit in 0.8PuCU treatment  increased by 2.68% and 4.96%, respectively, and the effective panicle number, total spikelet number and total grain number  decreased by 0.13%, 1.97% and 0.32%, respectively. It could be found that PuCU treatment was the best among the four treatments. Although 0.8 PuCU treatment reduced the amount of fertilizer applied, it still had the potential for increasing yield and improving efficiency compared with CU treatment, and its ratio of output to input was the highest. Correlation analysis showed that plant height, spike length, effective panicle number, total spikelet number and total grain number were significantly correlated with grain yield (P<0.05). To sum up, the application of polyurethane coated urea could effectively improve the yield composition of double-cropping early rice in Dongting Lake region, and reducing the application rate by 20% could not only stabilize the yield but also reduce the extravagant absorption of nitrogen, which was a more suitable fertilization method. However, there were differences in the controlled release effect of different coated fertilizers and the yield components of different crops, it was necessary to select the appropriate coated fertilizers according to the demand of crop varieties in local production.

Influences of Different Mechanical and Orderly Planting Methods on Growth Characteristics and Yield of rice

LUO Youyi, WANG Weiqin, ZHENG Huabin, LIU Gongyi, CHAO Ying, XU Cai, ZHENG Zhigang, LI Xueqian, WEI Yinlan, TANG Qiyuan

2021, 23(7):  162-171.  DOI: 10.13304/j.nykjdb.2020.0918

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The research and application of mechanical ordered hole direct seeding and mechanical orderly seedling throwing technology are of great significance to promote the mechanization, precision and order of rice planting. In order to  comparatively study  the effects of three kinds of mechanical orderly planting methods on rice growth characteristics and yield, Yongyou 4949 and Y liangyou 911 were used as test varieties, and the growth characteristics and yield formation of three mechanically ordered planting methods were studied by using split plot design.The results showed that the whole growth period of the two varieties showed machine transplanting > orderly machine throwing > order machine direct seeding. The whole growth period of the treatment of orderly machine throwing was 3～4 d shorter than that of machine transplanting, but it was 10～11 d longer than that of sequential machine direct seeding. The source of the difference in whole growth period was that the days from sowing seeds to the initial stage of young panicle differentiation was quite different. Compared with machine transplanting and machine hole direct seeding, the yield of the two varieties increased by 7.86%~8.50% and 14.06%~ 15.08%, respectively. The reasons for the increase of yield were as follows: the effective panicles per unit area significantly increased by 1470% and 12.20%, respectively, compared with machine transplanting and orderly machine direct seeding; the second reason was that the growth characteristics such as tiller number, dry matter accumulation, leaf area index and root biomass were significantly superior to the other two mechanical planting methods. At the same time, the production benefit of mechanical orderly throwing seedling cultivation was higher than the other two mechanical planting methods. To sum up, the orderly machine throwing planting mode had better early-onset and effective panicle foot in rice planting, which had more yield and benefit advantages than machine transplanting and machine hole direct seeding.





Impacts of Nitrogen Forms on Nitrogen Utilization and Yield of Wheat in Different Types of Soil

QI Xin, SI Yukun, ZHAO Yanan, HUANG Yufang, YAN Junying, SUN Xiaomei, YE Youliang

2021, 23(7):  172-181.  DOI: 10.13304/j.nykjdb.2020.0745

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In order to provide the basis for rational application of nitrogen (N) fertilizer, the different types of N fertilizers suitable for wheat growth were explored under different types of soils. ‘Yujiao 5’ was as the test material, and the pot experiment was carried out in Linying County of Henan Province during the wheat season of 2017—2018. The five forms of nitrogen fertilizers, such as urea (UR), ammonium nitrate (AN), ammonium sulfate (AS), calcium nitrate (CN) and ammonium chloride (AC), were applied in Chao soil (SC), Yellow cinnamon soil (SH) and Shajiang black soil (SS), respectively. And the accumulation of dry matter and the utilization of N in the leaf, and yield of wheat were analyzed under different treatments. The results showed that the responses of ‘Yujiao 5’ to N fertilizer were different in different types of soils. N fertilizers could be selected according to soil types. In SC, AS and AC were beneficial to the accumulation of dry matter, higher N utilization efficiency and partial productivity, which significantly increased yield of wheat. In SH, the performance of CN treatment was better. In SS, the accumulation of dry matter and yield of wheat were higher in CN and AS treatments. This study identified the different types of nitrogen fertilizers were more suitable for the growth of wheat under different types of soils, which provided  theoretical basis for the rational application of nitrogen fertilizer and the cultivation mode of high yield in wheat.

Effect of Deep Fertilization on Water Use Efficiency and Yield of Potato Under Vertical Rotary Tillage

YU Xianfeng, ZHANG Xucheng, MIAO Pinggui, FANG Yanjie, MA Yifan, WANG Hongli, HOU Huizhi

2021, 23(7):  182-190.  DOI: 10.13304/j.nykjdb.2020.0573

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The deep fertilization can improve nutrient utilization efficiency and reduce the risk of environmental pollution, and vertically rotary tillage (VRT) provides soil condition for deep fertilization. In this study the potato with plastic mulching and VRT was used as material, three treatments of fertilization depth were set, including no fertilization (VP), 15 cm of fertilization depth (VPF), 30 cm of fertilization depth (VPD). The soil water content, SPAD value, dry matter weight and tuber yield of potato were measured. The results showed that: VPD increased the SPAD value in leaf at later stage, especially  increased by 0.2%~13.8% at the starch accumulation stage, and the soil water contents in 0—200 cm soils was significantly decreased by 13.4%~39.0%. VPD could increase the number of potato, the weight of tuber per plant, the proportion of medium and large potatoes and the commodity rate, respectively. Compared with VPF and VP, the water consumption of VPD was decreased by 36.5%~43.3% before flowering, but increased by 49.8%~58.7% after flowering in 2018. The yields of VPD were increased by 7.7%~569%, and the water use efficiencies (WUE) of VPD and VPD were increased by 12.2%~28.2% and 16.8%~271%, respectively. Therefore, under the VRT condition in the semi-arid area of northwest China, the deep fertilization could increase the yield and WUE of potato, which should be beneficial to improve crop yield and utilization efficient of resources.

Influences of Oat Hay and Alfalfa Hay Combination with Different Grading Indexes on Rumen Fermentation of Yak in Vitro

XIA Hongze, HUANG Wenzhi, ZHANG Linlin, ZHANG Xiaohan, CUI Zhanhong, LIU Shujie

2021, 23(7):  199-201.  DOI: 10.13304/j.nykjdb.2020.1100

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In order to optimize the forage nutritional combination of yak diet with the grading index (GI), five combinations of alfalfa hay and oat hay with different GI (7.24, 6.40, 5.56, 4.72, 3.88) were selected to study rumen fermentation in vitro of yak. The fermentation time was set for 3, 6, 12, 24 and 48 h. The results showed that the gas production (GP), neutral detergent fiber degradation in vitro (NDFDIV), ammonia nitrogen (NH3-N), microbial protein (MCP), volatile fatty acids (VFAs) of GI=6.40 combination were higher or significantly higher than those of other  combination treatments in 3~48 h fermentations, which showed firstly increasing and then decreasing trend with the decreasing of GI. In treatments of 24~48 h fermentations, the dry matter disappearance in vitro (DMDIV) showed a trend of increasing first and then decreasing as GI decreasing, which reached the maximum value in GI=6.40 treatment. The multiply factors associative effects indexes (MFAEI) showed positive combination effects in treatments of GI=6.40 and 5.56 combination, while MFAEI showed negative combination effect in treatments of GI=3.88 combination. Overall, the effect of rumen fermentation in vitro of yak with GI=6.40 alfalfa hay and oat hay combination was best, which provided theoretical foundation for improving the reasonable collocation of roughage and the performance of house-feeding yaks on the Qinghai-Tibet Plateau.