Search

[Objective] The present paper aimed to promote the more effective transformation of agricultural scientific and technological a- chievements, it is necessary to build a stable transformation model and a scientific and reasonable profit distribution mechanism. [Method] The paper summarized the typical transformation models through field research on the relevant subjects involved in the transformation of agri- cultural scientific and technological achievements in Sichuan province. Considering the risk-taking, technological innovation and cooperation degree of participants, the paper constructed a benefit distribution model for the transformation of agricultural scientific and technological a- chievements based on the modified Shapley value method, and made a theoretical and empirical analysis on the benefit distribution mecha- nism of each subject in the transformation of agricultural scientific and technological achievements. [Result】(i) Government, research insti- tute, agricultural enterprises, dealers/retailers, village collective economic organizations, cooperatives/family farms/farmers have formed the transformation models of public welfare, operation and poverty alleviation. Resource sharing, complementary advantages, and coordinated development among cooperative entities in different models were conducive to reducing transaction costs, improving the efficiency of profes- sional division, realizing economies of scale and scope, and creating higher overall returns and individual benefits. (ii) Constructing a trans- formation model of agricultural scientific and technological achievements led by agricultural enterprises formed a higher efficiency of scientific and technological resource allocation and promoted the transformation of agricultural scientific and technological achievements. (iii) The re- vised benefit distribution method was more realistic and conducive to the long-term stability of cooperation due to the inclusion of the influ- ence of risk-taking, technological innovation and cooperation degree of participants. 【Conclusion】 By increasing policy support for agricultur-al enterprises leading scientific and technological innovation, enhancing the synergy of cooperative innovation among different subjects, and establishing a scientific and reasonable benefit distribution mechanism, it is conducive to promoting the effective transformation of agricultural scientific and technological achievements. [ABSTRACT FROM AUTHOR]

【Objective】The present paper aimed to explore the changes of eco-environmental quality brought by land use transformation and analyze the influencing factors of spatial differentiation of eco-environmental quality. It can provide scientific support for land management and regional planning in the social and ecological sustainable development of Sichuan province.【Method】Based on the remote sensing monitoring data of land use in Sichuan province in 2000, 2010 and 2020, starting from the dimension of land use function, the paper analyzed and studied the eco-environmental effects and influencing factors of land use transformation in Sichuan province from 2000 to 2020 by using land use transfer matrix, land use center of gravity migration, eco-environmental index, contribution rate of ecological quality and geographic detector.【Result】（i）The transformation of land function structure in Sichuan province from 2000 to 2020 was characterized by the transfer of agricultural production land to forest land and forage ecological land; Spatially, the transformation featured that the center of gravity of production and living land was constantly away from the geometric center, while the center of gravity of ecological land was continuously close to the geometric center.（ii）The eco-environmental quality index of Sichuan province in 2000, 2010 and 2020 was 0.4968, 0.4969 and 0.5009 respectively. The regional eco-environmental quality generally showed the distribution characteristics of ‘high in the West and low in the East’.（iii）From 2000 to 2010, the transfer of agricultural production land to forest and pasture ecological land was the main land transformation to promote the improvement of ecological environment; The transfer of forest land ecological land to pasture and other ecological land from 2000 to 2010 was the main land transformation leading to the deterioration of ecological environment. From 2010 to 2020, the production land of forest land would be transferred to agricultural production land, forage and other ecological land.（iv）The spatial differentiation of regional eco-environmental quality was affected by many factors such as nature, society and economy, among which elevation, topographic relief and population density were the main influencing factors.【Conclusion】The characteristics of land use transformation in Sichuan province are as follows: The center of gravity of production and living land is constantly deviated from the geometric center of gravity, and the imbalance of production and living space distribution is enhanced. The center of gravity of ecological land keeps approaching the geometric center of gravity, and the spatial distribution of ecological land tends to be balanced; The changing characteristics of ecological environment quality are as follows: The ecological environment quality index is constantly increasing, the area of high-quality and high-quality ecological environment areas is rising, and the overall regional ecological environment quality structure is constantly optimized; Explore the impact mechanism of spatial differentiation of eco-environmental effects, and draw the conclusion that regional eco-environmental quality differentiation is mainly affected by elevation, terrain undulation and population density. [ABSTRACT FROM AUTHOR]

【Objective】 The present paper aimed to investigate the comprehensive effects of irrigation amount on soil enzyme activity, yield, quality and nutrient utilization of pepper in Sichuan Basin, and propose an appropriate irrigation amount. 【Method】 The pepper variety of Xingshuzhoula 3 was used as the experiment material. Four irrigation amount treatments were set, and the soil volumetric moisture content was controlled respectively at 35%-40% (T1), 45%-50% (T2), 55%-60% (T3), 65%-70% (T4). The soil urease, neutral phosphatase, sucrase β-Glucosidase activity and catalase activity such as yield, quality, and plant N, P, K content of peppers were determined. The interrelationship between the indicators was analyzed. 【Result】 The soil enzyme activities increased with the increase of irrigation amount. The soil urease, neutral phosphatase, sucrase, β-glucosidase and catalase activities of T4 were the highest, and the activities of some enzymes were not significantly different from those of T3.Compared with T1, the increases were 48.80%, 28.70%, 45.60%, 100.87% and 102.58%, respectively. With the increase of irrigation amount, pepper yield also increased, T4 increased by 29.05% compared with T1, and there was no significant difference in pepper yield between T3 and T4.The content of vitamin C and capsaicin in peppers decreased gradually with the increase of irrigation water, but the content of soluble sugar in peppers increased with the increase of irrigation water. The amount of irrigation increased the total accumulation of nutrients (N, P and K), the physiological use efficiency of N and K and the partial fertilizer productivity in pepper fruits and shoots. Except that the physiological utilization efficiency of P was lower than that of T4, the other nutrient utilization parameters of T3 were not significantly different from those of T4, and the physiological utilization efficiency of K was even significantly higher than that of T4.【Conclusion】When the irrigation amount is 4392-4733 t/hm² (T3 and T4), the soil enzyme activity, yield and nutrient utilization rate of pepper are all at high levels. The results of the study provide a theoretical and practical reference for the selection of the irrigation amount of facilities pepper in Sichuan Basin. [ABSTRACT FROM AUTHOR]

【Objective】 The present paper aimed to optimize the composition of alkaloid in Sichuan cigar and realize the quality improvement and harm reduction of cigar, the conversion degree of nicotine to nornicotine and the distribution of nicotine conversion rate between plants among the main cigar varieties were determined, and variety purification was carried out according to the conversion traits of nicotine.【Method】 Dexue 1, Dexue 3, Dexue 4, Dexue 5, Dexue 7 and Shiyan 1 were used as test materials. The content of alkaloids and TSNAs in the middle leaves of the tested varieties were determined and analyzed. The main cultivars in Sichuan (Dexue 4, Dexue 7 and Shiyan 1) were purified by early conversion stimulation and converter identification. 【Result】 (i) The alkaloid composition and contents in Sichuan cigar varieties were significantly different, and there were different degrees of nicotine conversion in different varieties, and the distribution of nicotine conversion rate between plants was quite different. The nicotine conversion problem of Dexue 5 was prominent. The proportion of converters in the tested group was 100%, and all converters were high converter. There were a large number of nicotine converters in Shiyan 1, among which the low converters were the majority, accounting for 37.9% of the total population. The problems of nicotine conversion in Dexue 1 and Dexue 3 were relatively less serious with all the tested plants being low converters. The conversion rate of Dexue 4 and Dexue 7 were 48% and 30%, respectively. (ii) Based on the early conversion stimulation and converter identification of Dexue 4, Dexue 7 and Shiyan 1, the non-converters were strictly selected for self-fertilize, and the corresponding purified species seeds were obtained. Compared with the corresponding conventional varieties, the nicotine content and nicotine conversion rate of purified variety were significantly reduced, the NNN contents and the total amount of TSNAs were significantly reduced, and the NNN contents of Dexue 7 was reduced from 2615.27 ng/g to 442.67 ng/g, the total amount of TSNAs decreased from 3602.46 ng/g to 1327.24 ng/g, and the NNN contents of Dexue 4 and Shiyan 1 decreased from 3235.76 and 3940.32 ng/g to 945.32 and 1315.40 ng/g, the total amount of TSNAs decreased from 5658.51 and 6669.89 ng/g to 2889.81 and 2840.12 ng/g. The purified variety had better cigar flavor. 【Conclusion】 Sichuan cigar varieties have different degree of nicotine conversion problems. By early conversion stimulation and converter identification and strictly selecting non-converters to self-fertilize for the purification, conversion rate and tobacco-specific nitrosamine contents can be effectively reduced, the quality and safety of cigar can be improved. [ABSTRACT FROM AUTHOR]

【Objective】In recent years, the wheat in Sichuan province is threatened by Fusarium head blight（FHB） or scab as changes in climate and farming practices.The present paper aimed to obtain the genetic resources of resistance to FHB in Sichuan wheat varieties, and breed wheat for resistance to FHB.【Method】In the research, 156 wheat varieties or high-generation lines with moderate resistance to FHB were identified by soil surface inoculation.The resistance gene composition of these wheat varieties was detected by molecular markers of FHB resistance genes Fhb1, Fhb2, Fhb4 and Fhb5, as well as some stripe rust resistance genes and powdery mildew resistance gene.【Result】Through molecular detection of disease resistance genes, it was found that 20yin979 and 20jian2506-10 contained the FHB resistance genes Fhb1 and Fhb5, respectively. For stripe rust resistance genes detection, 4, 63, 9, 3 and 14 wheat materials containing the Yr5, Yr15, Yr18, Yr26 and YrAs2388 were detected, respectively. And the distribution frequencies of rust resistance genes Yr5, Yr15, Yr18, Yr26 and YrAs2388 were 2.56%, 40.38%, 5.77%, 1.92% and 8.97%, respectively. A total of 44 materials containing the powdery mildew resistance gene Pm21 were detected, and the distribution frequency in the tested materials was 28.21%.The distribution of resistance genes showed that 122 materials contained at least one resistance gene.Among them, 6 materials contained both strip rust and powdery mildew resistance genes, 9 materials contained 2 strip rust resistance genes, and the remaining 106 materials contained only 1 resistance gene. The only material 20jian2506-10 contained three resistance genes of FHB, stripe rust and powdery mildew.【Conclusion】These results indicate that Sichuan wheat lacks FHB resistance resources with explicit genetic background.Therefore, Sichuan wheat FHB resistance breeding should strengthen the introduction of known resistance resources while making full use of the local FHB resistance resources. [ABSTRACT FROM AUTHOR]

【Objective】The present paper aimed to explore the physiological mechanism of kiwifruit pulp colour difference, so as to provide a reference for kiwifruit pulp colour directional breeding. 【Method】Six main kiwifruit varieties in Sichuan province were used as tested materials, the representative periods of fruit development were selected, and the contents of soluble solids, dry matter, total acid, Vc, soluble protein, soluble starch, total phenols, flavonoids and main pigments, as well as the scavenging rates of ABTS free radical, DPPH free radical and hydroxyl free radical were tested, meanwhile the changes of main physiological indexes and their correlation with pulp colour were studied. 【Result】The changes of main physiological indexes of different varieties in fruit development period basically tended to be the same, ‘Hongshi 2’ and ‘Jinshi 1’ maintained high contents of total phenol, Vc and total acid during the whole fruit development period and were significantly higher than the other four varieties in DPPH, ABTS and hydroxyl radical scavenging capacity. In the early stage of fruit harvest, the dry matter content of ‘Hongyang’ was significantly higher than that of the other five varieties, the acid content was the lowest, and the soluble protein content of ‘Cuiyu’ was the highest. It was shown in the results of the analysis on the correlation between physiological index and pigment content that the flavonoid content was significantly or extremely significantly positively-correlated with the pigment content in kiwifruits of different varieties, the hydroxyl radical scavenging rate, vitamin C content and titratable acid content were significantly or extremely significantly negatively-correlated with the pigment content in kiwifruits of several varieties, and the scavenging rates of DPPH and ABTS free radicals, as well as the contents of dry matter, total soluble solid, soluble starch and soluble protein were not consistently correlated with the pigment content in kiwifruits of different varieties. 【Conclusion】There is a significant correlation between the color difference of kiwifruit pulp and some physiological indexes. When breeding, the parent configuration combination matching the target characters can be selected through the test of physiological indexes related to the color of parent pulp. [ABSTRACT FROM AUTHOR]

【Objective】 The present paper aimed to study the spatial and temporal distribution characteristics of low-temperature continuous rain disasters in rice during the heaving-heading stage in Sichuan province, in order to provide scientific basis for disaster prevention and reduction of low-temperature continuous rain disasters in rice at different growth stages in Sichuan province. 【Method】 According to the topographic and geomorphic types of Sichuan province, the rice planting regions were divided into six regions, namely, the marginal mountain region around the basin, the parallel range-valley region in the east of the basin, the hilly region in the south of the basin, the shallow hilly region in the middle of the basin, the flat hill region in the west of the basin and the mountainous region in the southwest of Sichuan. Based on the data of daily mean temperature, maximum temperature, minimum temperature, precipitation and sunshine duration of 21 agricultural meteorological stations in Sichuan province from 1961 to 2020, the spatial and temporal distribution characteristics of low-temperature continuous rain during the period of rice starting from heading to heading were analyzed by using statistical analysis method combined with evaluation indexes of low-temperature continuous rain. 【Result】 (i) The frequency of mild, moderate and severe cold damage of rice during booting and heading stage in Sichuan province was as follows: 0%-32.5%, 0%-44.8% and 0%-50.3%, and the large values were all in the southwest Mountain area of Sichuan. Although the occurrence frequency of mild and moderate cold damage was relatively low, the distribution area of mild cold damage was the widest, followed by moderate cold damage, and the distribution area of severe cold damage was the smallest, only in the southwest Mountain area of Sichuan. (ii) The frequency of mild, moderate and severe continuous rain disasters were 0.4%-3.8%, 0%-5.2% and 0%-0.5%, respectively. (iii) The frequency of low-temperature continuous rain disasters was 0%-9.1% from 1961 to 2020, 0%-9.1% from 1991 to 2000, and 0%-3.3% from 1961 to 1970. (iv) From 1961 to 2020, the frequency of low temperature cold damage and low temperature continuous rain disaster passed the significance test of 0.05 over time, showing a decreasing trend. The frequency of continuous rain disaster did not change significantly with time and did not pass the morphological significance test of 0.05. 【Conclusion】 The frequency of low-temperature continuous rain disaster was high in the mountainous area of southwest Sichuan. In Sichuan province, the continuous low temperature rain disaster of rice during booting and heading stage showed a decreasing trend in recent years, which was consistent with the results of the reduction of low temperature cold damage and continuous rain disaster under the background of climate warming. [ABSTRACT FROM AUTHOR]

[Objective]The present paper aimed to understand the cold tolerance of sugarcane main parents and the change characteristics of cold tolerance evaluation related traits, and to provide reference for breeding cold tolerance sugarcane varieties and reducing the harm of frost to sugarcane production. [Method] A total of 102 parents were selected for natural frost test in 5 crops consisted of two plant cane( 2017P and 2019P) and 3-year ratoon crops(2018F, 2019S and 2020F) during 2017-2020 in Zizhong, Sichuan, a frost prone area. The correlation analysis, variance analysis, calculation of broad sense heritability and cluster classification were processed. [Result] It was found that there were differences in the types and degree of cold damaged traits among parents under low temperature environments, and ratoon cane was more vulnerable than plant cane. The damaged traits were significantly ( P < 0. 05 ) correlated with some agronomic characters under cold or light frost. The performance of damaged traits was affected by parent, year and their interaction. The damage rate of plant was a high heritability trait, which can be used to evaluate cold tolerance under cold and light frost. The damage rate of stalk length and internode were medium heritability traits, which were less affected by low temperature environments, and can be used to evaluate cold tolerance, and the damage rate of internode was slightly better than that of stalk length. The percentage of green leaves varies greatly among years, which can be used for cold tolerance evaluation under light or moderate frost. The percentage of parental variance decreased, and the heritability also decreased when combined data from different trials were used for variance analysis. Cluster classification showed that trials plant crops in 2017 and 2019 were not suitable for the evaluation of cold tolerance of parents. Among the tested parents, 58. 89% of the parents were identified as good or better cold tolerance and 23. 53 % as poor or poorer.[Conclusion] There are differences in the types and degree of cold damaged traits among parents under low temperature environments, and the cold tolerance of sugarcane belongs to medium to high heritability. The traits that can be used for cold tolerance evaluation are affected by the degree of low temperature. Mild and severe low temperature stress should be set for indoor cold tolerance test. [ABSTRACT FROM AUTHOR]

[Objective] The present paper explored the spatial distribution pattern and driving factors of aquaculture in Sichuan province, which aimed to provide reference for optimizing the layout of aquaculture and then promoting the quality and product of this industry. [Method] Taking the country (municipal district) of Sichuan province as the basic spatial research unit, with the help of the province' s fishery statistical yearbook and local one, the spatial distribution pattern, influencing facotrs and spatial heterogeneity of domaint factors of aquaculture in Sichuan province were analyzed by using the spatial autocorrelation analysis method (Moran' s I), the geo-detercor and the geographically weighted regression (GWR) model respectively. [Result] The results showed that both aquaculture area and product were characterised by a significantby positive spatial correlation and the plain and hilly areas along the Minjiang and Tuojiang Rivers in eastern Sichuan (including Rong county, Weiyuan county, Zizhong county, Jingyan county, Renshou county, Yanjiang district, Jianyang city, etc.) were the province' s primary aquaculture cluster; the aquaculture area, average yield level, the number of freshwater fish fry and aquaculture labor force were main influencing factors of aquaculture product in Sichuan province ; In the positive regression coefficient effect of domain factors, aquaculture area decreased from the middle to the nonh and south sides, the average yield level decreased from the nonheast to the southwest and the number of freshwater fish fry decreased from the nonh to the south. And the aquaculture labor force transited from negative value to positive value from the southeast to the west, and gradually increased. [Conclusion] The research on the spatial pattern and influencing factors of aquaculture in Sichuan province would provide a scientific basis for the intensive and differentiated development of aquaculture in this province, and would be one of the effective means to optimize the layout of aquaculture in Sichuan province and then promote the sustainable development of the industry. [ABSTRACT FROM AUTHOR]

[Objective] The present paper aimed to analyze the main factors affecting the yield of Brassica napus L in different regions of Sichuan province, so as to provide theoretical basis for breeding B. napus L. varieties suitable for different rapeseed producing areas in Sichuan province. [Method] Variation analysis, correlation analysis and path analysis were used to analyze the relationship between the agronomic characters and the yield of B. napus L . [Result] In Xindu, Deyang and Dazhou regions, the most variation of agronomic trait was the first branch numbers. The value was the number of seeds per siliquain Chongzhou and Mianyang regions. It was the number of effective siliqua per plant in Nanchang, Yibin, Jianyang, and Leshan regions. The least variation of agronomic traits was the plant hight, in the Xindu, Chongzhou, Jianyang, Mianyang, and Deyang regions. It was 1000-seed weight, in the Nanchang, Yibin, Leshan, and Dazhou regions. The yield of Xindu region was significant or highly significant negative correlated with the first branch numbers and the number of effective siliqua per plant But, it was significant positive correlated with the plant hight and the number of seeds per siliqua. The yield of Nanchang region was significant or highly significant positive correlated with the plant hight, the first branch numbers, and the number of effective siliqua per plant. The yield of Yibin region was highly significant positive correlated with the plant hight. The yield of Jianyang region was significant or highly significant positive correlated with the number of effective siliqua per plant and the number of seeds per siliqua. But, it was highly significant negative correlated with the 1000-seed weight. The yield of Leshan region was significant positive correlated with the number of effective siliqua per plant. There was no significant correlation between yield and main agronomic traits in Mianyang, Deyang, and Dazhou region. In Xindu region, the greatest direct path coefficient and the greatest comprehensive effects were respectively the number of seeds per siliqua and the the number of effective siliqua per plant. Those were both the number of seeds per siliqua in Chongzhou region. In Nanchong and Jianyang regions, the greatest direct path coefficient and the greatest comprehensive effects were respectively the number of seeds per siliqua and the 1000-seed weight. Those values were respectively the number of effective siliqua per plant and the first branch numbers in both Mianyang and Dazhou regions. In Deyang region, the greatest direct path coefficient and the greatest comprehensive effects were both the number of effective siliqua per plant. [Conclusion] There were differences in the coefficient of variation of main agronomic traits of B. napus L in different producing areas of Sichuan province, and there were differences in correlation with yield. The effects of yield components on yield should be fully considered in breeding, as well as the comprehensive effects of other traits. The present study provides a scientific basis for breeding B. napus L varieties suitable for different regions of Sichuan province. [ABSTRACT FROM AUTHOR]

【Objective】Water shortage in dry season and nutrient deficit in Liangshan Prefecture, Sichuan Province are the main factors limiting agricultural production. The present paper aimed to investigate the effects of biochar and polyacrylamide on water and fertilizer retention capacity of purple soil in Liangshan Yi Autonomous Prefecture.【Method】The field experiment was carried out with biochar application rates of 0, 10, 20, 40, 60 t/hm~2, polyacrylamide application rates of 0, 45, 90, 135, 180 kg/hm~2. 【Result】Compared with control, the percentage of effective particle size of >50 μm increased by 8.9 % under 60 t/hm~2 biochar treatment, 7.4 % under 180 kg/hm~2 polyacrylamide treatment, respectively; the soil bulk density decreased by 17.0 % under the treatment of 60 t/hm~2 biochar, which was 1.08 g/cm~3, and decreased by 13.1 % under the treatment of 135 kg/hm~2 polyacrylamide which was 1.13 g/cm~3; The soil saturated water content increased linely with the increasing application rates of biochar, 60 t/hm~2 biochar treatment increased by 20.8 %, which was 51.2 %. However, the soil saturated water content, field water holding capacity and the capillary water content increased first and then decreased with the increasing application rates of polyacrylamide, and 180 kg/hm~2 polyacrylamide treatment increased by 23.5 %, 21.3 % and 25.0 % which was 53.9 %, 32.3 % and 45.6 %, respectively. For soil organic matter, the treatment of 60 t/hm~2 biochar, the treatment of 135 and 180 kg/hm~2 polyacrylamide were improved by 86.4 %, 146.4 % and 186.4 % which was 11.52,15.23 and 17.70 g/kg, respectively. 【Conclusion】The application of biochar and polyacrylamide can improve the soil structure and the ability of purple soil to store water and maintain fertilizer. The most suitable biochar and polyacrylamide application rate were found to be 60 t/hm~2 and 135 kg/hm~2, respectively. [ABSTRACT FROM AUTHOR]

[Objective] The present paper aimed to understand the demand characteristics of N,P,K and the fertilizer utilization rate of corn in Sichuan mountainous and hilly areas. [Method] The field experiments of farmers' habitual fertilization (Cl) and no-fertilization (CK) in mountainous and hilly areas of Sichuan province were conducted to study the N,P,K demand of maize in different periods during the whole growth period and the fertilizer utilization rate and nutrient harvest index under fertilization conditions. [Result] The N, P and K uptake in maize accounted for the whole growth period from sowing date to trefoil stage were 1.34%, 5.33% and 10.33% ;From trefoil stage to jointing stage:4. 54%, 30. 76% and 14.42% ;From jointing stage to heading stage: 29. 74%, 29. 48% and 29. 14% ; From heading stage to silking stage:25. 7%, — 1. 84% and 46.84% ;From silking stage to maturing stage:38. 69%, 36. 27% and —0.72% ;The nitrogen and phosphorus demand of maize in late growth stage was mainly grain, potassium was stem and grain; In Zhongjiang and Guangyuan experimental sites, the contribution rates of conventional fertilizer to maize yield were 27. 98% and 25. 09%, the harvest index ranges of N,P and K were 0.65 —0.67,0.64 — 0. 66 and 0.30 —0.33, and compared with no fertilization, fertilization promoted the transfer of photosynthate to grain, but did not reach the significant level. [Conclusion] There is poor coordination between fertilization and demand of maize in Sichuan area, low fertilizer utilization rate, which affects maize yield and quality. The fertilization methods or types need to be further improved. [ABSTRACT FROM AUTHOR]

[Objective] The present paper aimed to optimize pre-basic seed production and manipulate N nutrient management by aeroponics, effects of N levels on N, P and K uptake and distribution of potato during different growth stages were studied. [ Method] The experiment was laid out in a randomized block design of two factors with two potato cultivars of Chuanyul 17 and Mira by aeroponics. N levels were set at 5 levels of 120, 240, 360, 480 and 600 mg/L. In different growth stages, dry matter weight, nitrogen, phosphorus and potassium contents of different parts of plant were measured. Dry matter accumulation, nitrogen, phosphorus and potassium contents, uptake and distribution were analyzed. [Result] ( i) In the same N level, the dry matter accumulation of Mira was higher than that of Chuanyu 117 at the same grow period. The highest dry matter accumulations were achieved under the N level 240 mg/ L in the same growth stages with two cultivars. The dry matter accumulation of Chuanyu 117 and Mira was 2. 86 and 4. 23 g/plant in N Level 240 mg/L at 90 days after transplanting ( DAT) respectively. ( ii) The content of Nitrogen ( N), phosphorus ( P) and potassium ( K) in different organs increased as the nitrogen level increased at different growth stages with the two cultivars. The uptake and accumulation of N, P and K was higher under the N 240 mg/ L treatment than that of other N levels at 90 DAT, respectively, Chuanyul17 were 0. 306, 0. 070 and 0. 544 g!plant respectively; Mira were 0. 489, 0. 117 and 0. 899 g/plant. ( iii ) At the same growth periods, the distribution ratio of N, P and K in leave, stem and root under middle N levels was higher than that of low or high N levels, but the effect on tubers was contrary to the above. The distribution ratio of N, P and K in leave, stem and root was high at the early stage, and then N, P and K was transferred to tubers in the late growth stages. ( iv) The tuber number and weight per plant reached a maximum under the N level of 240 mg/ L with the two cultivars, respectively, was 24. 78 grain/plant, 53. 78 g/plant for Chuanyu 117, and 29. 31 grain/ plant, 82. 23 g/plant for Mira. [Conclusion ] Increasing nitrogen in an appropriate amount can promote the uptake and accumulation of nitrogen, phosphorus and potassium in plants, which is beneficial to the improvement of pre-basic seed production. Under the condition of low light intens ity ecology in Sichuan basin, we can obtain higher yield of potato pre-basic seeds under nitrogen level of 240 mg/L by aeroponics. [ABSTRACT FROM AUTHOR]

[ Objective] The present paper aimed to reasonably use local agricultural climate resources and scientifically carry out maize planting. [ Method] According to climate data (1961 -2017) of 124 meteorological stations and long-term records (1981 - 2017) of maize phenology from 15 agricultural stations of Sichuan, the temporal and spatial distribution of light resources, temperature resources and precipitation during key maize phenological stages were analyzed in Sichuan Province. [Result] The total radiation during the whole growing period and different growth stages of maize both showed decreased trends. The higher radiation resources distributed to the southwestern of the basin and the southern of the Panxi agricultural area. The heat resources during maize growth period showed an increasing trend. Diurnal temperature range of Panxi agricultural area is obviously higher than the basin area. The reference evapotranspiration during each maize growth stages decreased. Water resources shortage occurred in most Panxi agricultural area and the old arid areas in the basin. [ Conclusion ] All regions should make rational use of light, temperature and water resources to provide scientific basis for relevant departments to formulate agricultural production measures and ensure the development of high yield and high quality of corn. [ABSTRACT FROM AUTHOR]

[Objective] The present paper aimed to evaluate the potential of white clover (Trifolium repens L.) as forage grass and ecological engineering plant on paddy field ridges in southern China. [Method] The clover was planted on the ridge of paddy fields in Ilengnan, Ilunan province and Jiangyou, Sichuan province in the spring of 2015. Cabover-ground parts, mainly leaves and petioles, were harvested monthly from July of 2016 to June of 2017. Dry matter was weighted after desiccation in a stove at 105 °C for 15 minutes and 70 °C for 24 hours. Dry samples harvested in the same season were mixed after storing at -20 °C . The contents of crude protein, nitrogen, phosphorus and potassium of such mixed samples were then determined by the standard procedures. The antagonism experiment with Alternant her a philoxeroides was conducted by face-to-face cultivation in concreted circles located in a plastic greenhouse from July of 2017 to March of 2018. [Result] At the experiment site in Sichuan, the highest dry matter weight of the white clove was obtained at the first harvest and the dropped until January of 2017 and increase gradually till the end of the experiment. It dropped also in Ilunan after the first harvest but started to increase since August and reached the highest point in April of 2017. The contents of crude protein, nitrogen and phosphorus were the highest in the first quarter at both sites. The content of potassium was the highest in the third quarter at Jiangvou but in the second quarter at Ilengnan. In the antagonism experiment, the growth of A. philoxeroides under each treatment was obviously better than that of clover in the summer, but white clover grew significantly better than A. philoxeroides under each irrigation regime and dominated the community in terms of occupying area, fresh weight and dry weight. [Conclusion] White clover on paddy didges has shown strong regeneration ability both in Sichuan and Hunan and could be used as high-quality forage and green manure crop. It could strongly inhibit the growth of A. philoxeroides at low temperature and soil humidity. [ABSTRACT FROM AUTHOR]

[Objective (The present paper aimed to understand the distribution and infection of NycopZ+ma in yaks of Qinghai-Tibet plateau in China. % Method】 In this study, 959 yak serum samples (56 from Sichuan, 243 fromGansu, 436 fromTibet and 224 from Qing- hai) were collected fromQinghai-Tibet plateau and tested for rerumantibodies by ELISA. % Result】 The results showed that the positive rate of Mycoplasma bovis antil)〇dy in yak her(ds on Qinghai-Til)et plateau was 48.70 %. If the distribution of the antibody in Sichuan, Gansu, Tibet and Qinghai provinces was observed, the positive rate was 64. 29 53. 09 46.10 % and 45 . 09 %. I the infection age was con¬ sidered , the positive rate was 55.70 % for tliose under one year ol(d, 46.20 % for tliose aged 1 - 2, 45.23 % for tliose aged 3-6 years and 49. 70 % for those over six years old. The positive rate of male and female was 45. 71 % and 50. 24 % respectively. Chi-square test with SPSS21 . 0 software showed that there was no significant difference in the positive rate of serumantibodies between Sichuan and Gansu ( P> 0. 05), but significant difference between Sichuan and Qinghai and Tibet ( P<0. 05), but there was no significant difference among Gan¬su, Tibet and Qinghai ( P> 0. 05) ； there was no significant difference in the age of infection among the four provinces (regions . 05) ； the females of Sichuan，Gansu and Qinghai were higher than males. But there was no significant difference between Sichuan and Qinghai ( P > 0. 05 )， only Gansu ( P < 0. 05 )， while Tiljetan males were higher than females， but the difer- ence was not significant ( P > 0. 05 ).[Conclusion 】It shows that Mycplsma bo— is widespread and prevalent in Yak herds on the Qinghai-Tibet plateau in China，especially in Sichuan， Tibet and Qinghai provinces showing an obvious upward trend year by year [ABSTRACT FROM AUTHOR]

[Objective (The present paper aims to explore the effects of planting density on photosynthesis and yield of cucumber in the Si¬chuan Basin. ' Method】 Cucumber ‘ Chuanlv No. 11 ’ taken as material，five cultivation densities were set up. The chlorophyll content，leaf area，photosynthetic gas exchange parameters，chlorophyll fluorescence parameters and yield indicators of different leaf positions of cucumber in different density were determined. ' Result】 The effect of planting density on the photosynthetic apparatus of different parts of cucumber was also different. The lowering of net photosynthetic rate of cucumber plants from bottom to top was caused by non-stomatal factors，non- stomatal and stomatal factors，and stomatal factors. There might be a photosynthetic compensation mechanism; As the density of cucumber decreased，the yield per plant increased gradually，but the yield per 667m2 gradually decreased. ' Conclusion】 The study reveals the effects of different cultivation densities on different leaf positions of cucumber and provides a theoretical basis for the selection of cucumber planting density in spring in Sichuan basin. [ABSTRACT FROM AUTHOR]

【Objective】Due to the large fragmentation of cultivated land in hilly regions, it is difficult to extract high-precision cultivated land information by medium-resolution remote sensing images. How to improve the classification accuracy of applying medium-resolution remote sensing images to extract cultivated land in hilly regions is an urgent problem to be solved. 【Method】Based on the difference of cultivated land and other landforms in time series of vegetation cover and the analysis of multi-temporal remote sensing images, this paper proposed a method of cultivated land extraction based on combining crop tillage rhythm and multi-temporal remote sensing images. 【Result】Using this method success extract the cultivated land in Huili, Sichuan, which showed that the method was suitable for extraction of cultivated land in hilly regions. 【Conclusion】This method has high extraction speed, and the result has certain current situation and high accuracy. It can meet the requirements for timely acquisition of cultivated land information in cultivated land use and management and can be applied to the correction of land parcels in historical farmland vector data, and to update the missing points. [ABSTRACT FROM AUTHOR]

【Objective】The present paper aimed to evaluate the epidemic status of common pathogens large-scale pig farms in Sichuan.【Method】In this study, 283 samples(pathological tissues, boar semen, miscarriage and stillbirth) were collected and detected by bacterial isolation and identification, RT-PCR, PCR. 【Result】The positive rates of CSFV, PRRSV, PRRSV NADC30-Like, PCV2, PRV, APP, PM and SS2 in the pathological tissues samples of 106 pigs were 7.55 %(8/106),40.57 %(43/106), 20.75 %(22/106),34.91 %(37/106),16.04 %(17/106),9.43 %(10/106),19.81 %(21/106) and 4.72 %(5/106), respectively. Among the percentage of multiply infections was 60.49 %(49/81). The pathogens infection of PRRSV or PCV2 not only emerges in throughout the year but also occurs frequently with other pathogens infection and bacterial infection are most common in summer. The positive rates of CSFV, PRRSV, PCV2 and PRV in 68 boar semen samples were 10.29 %(7/68), 30.88 %(21/68), 20.59 %(14/68) and 20.59 %(14/68), respectively. Among the 38 positive samples, the percentage of single infections was 52.63 %(20/38). The positive rates of CSFV, PRRSV, PCV2 and PRV in 63 miscarriage and stillbirth samples were 6.35 %(4/63),46.03 %(29/63),38.10 %(24/63) and 30.16 %(19/63), respectively. The most common infection type was PRRSV with other pathogens infection and PRRSV was more common in throughout the year and the percentage of multiply infections was 74.50 %(38/51). The infections of PEDV and PoRV are common in spring, autumn and winter. The positive rate of PEDV and PORV were 56.52 %(26/46) and 26.09 %(12/46) in intestinal mucosa and feces of 46 diarrhea pig samples.【Conclusion】The Prevention and control of PRRSV, PCV2, PRV and PEDV were still key point in the future, meanwhile, the multiple pathogen infection and new variants PRRSV NADC30-Like is also difficult to prevent from large-scale pig farms in Sichuan area. [ABSTRACT FROM AUTHOR]

【Objective】The present paper aimed to explore the application effect of ’gather soil ridging + narrow strains with broad-rows’ cultivation mode in Sichuan Basin, and provide scientific guidance and theoretical basis for peach ochard establishment in Sichuan Basin and southern shallow hills in the future. 【Method】This study compared the effects of different cultivation modes on the growth, yield, quality and economic benefits of peach cultivars ’Xiahui No.6’. 【Result】The results showed that the diameter of trunks, main branches, lateral branchs, length of regenerated branches, number of roots less than 0.50 cm, chlorophyll content of leaves, fruit soluble solids and total sugar content and solid acid ratio, yield per plant for ’gather soil ridging + narrow strains with broad-rows’ were markedly higher than for the control group after planting 39 months; However, there was no significant difference in the appearance quality and output value of peach fruit per unit area under two different cultivation modes. 【Conclusion】’Gather soil ridging + narrow strains with broad-rows’ and combined with tree pruning can effectively extend canopy, improve plant light conditions, enhance the peach plant growth, improve the quality of the fruit flavor, which is a practical and efficient cultivation mode for southern peach orchard. [ABSTRACT FROM AUTHOR]

[Objective] This paper aimed to study the effects of germination temperature on potato production and tuberization. [Method] At Jintang county of Sichuan, three germination temperature levels such as 1.5, 10-15 (room temperature) and 20°C, were used in this experiment before sowing. [Result] With the increasing of germination temperature, the germination speed of seed potato increased. At the end of germination, the bud diameter, bud length and bud number of treatment room temperature and 20°C were significantly higher than that of treatment 1.5°C,. During the sprouting period of seed tuber, ABA content was a decreasing trend, and the descending speed was faster with the increasing of germination temperature, but the content of IAA, CTK and GA increased totally during the sprouting period of seed tuber. After seedling, the higher germination temperature was, the more stem number was, and the lower stem diameter. At the early growth stage, the plant height increased with the increasing of germination temperature while at the later growth stage, the plant height was opposite. Compared with treatment 1.5°C , the fresh yield of treatment of room temperature and 20°C, was increased by 15. 3 % and 15. 6 % while the tu-ber number per plant of that was increased bv 18. 8 % and 23. 9 % , respectively. At the same lime, I lie proportion of tuber that≥90 g decreased, and the proportion of 30 -60 g tuber increased, but there was no significant effect on commodity potato rate. [Conclusion] Properly increasing the germination temperature of purple potato before sowing would improve the population number, increase tuber number and yield, and change the tuber size distribution. [ABSTRACT FROM AUTHOR]