scholarly journals Effects of Fungicides and Spray Application Interval on Controlling Marssonina Blotch of Apple in the Loess Plateau Region of China

Plant Disease ◽  
2017 ◽  
Vol 101 (4) ◽  
pp. 568-575 ◽  
Author(s):  
J. L. Dang ◽  
M. L. Gleason ◽  
C. K. Niu ◽  
X. Liu ◽  
Y. Z. Guo ◽  
...  
Keyword(s):  
Loess Plateau ◽  
Mycelial Growth ◽  
Bordeaux Mixture ◽  
Field Tests ◽  
Conidial Germination ◽  
Shaanxi Province ◽  
The Loess Plateau ◽  
Plateau Region ◽  
Normal Rainfall

Marssonina blotch, caused by the fungus Marssonina coronariae, is a serious foliar disease on apple in East Asia as well as in other moist temperate regions in Asia, Europe, and South America. Several fungicides were investigated for their toxicity to mycelial growth and conidial germination of the pathogen in vitro. Tebuconazole, kresoxim-methyl, hexaconazole, propiconazole, and a mixture of tebuconazole and benziothiazolinone sharply inhibited mycelial growth but had less effect on conidial germination. Field tests were conducted in a commercial orchard in Baishui County, Shaanxi Province, China, during 2012, 2013, 2014, and 2015 in order to develop recommendations for apple growers. Three applications of tebuconazole, hexaconazole, propiconazole, or a mixture of tebuconazole and benziothiazolinone at 20-day intervals from early July to late August resulted in defoliation incidence of <5%. When sprays of Bordeaux mixture + tebuconazole, Bordeaux mixture + propiconazole, and Bordeaux mixture + tebuconazole and benziothiazolinone were alternated, the spray interval was extended to 25 days and defoliation incidence remained <5%. Based on historical records and our results, scouting for symptoms should begin in mid-June. We recommend commencing the spray period in early July in years with normal rainfall patterns, and spraying in mid- to late June in years with much rainfall. The findings of this study create a foundation for implementation of an efficient spray program against Marssonina leaf blotch in apple orchards in the Loess Plateau Region of China.

scholarly journals Appropriate Management Scale of Farmland and Regional Differences under Different Objectives in Shaanxi Province, China

Land ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 314
Author(s):  
Qianxi Zhang ◽  
Zehui Chen ◽  
Fei Li
Keyword(s):  
Influencing Factors ◽  
Loess Plateau ◽  
Regional Differences ◽  
Agricultural Development ◽  
Shaanxi Province ◽  
Employment Rate ◽  
Grain Production ◽  
The Loess Plateau ◽  
Surplus Labor ◽  
The Government

Agricultural development is facing two problems: insufficient grain production and low profit of farmers. There is a contradiction between the government’s goal of increasing production and the farmer’s goal of increasing profit. Exploring the appropriate management scale of farmland under different objectives is of great significance to alleviate the conflict of interests between the government and farmers. In this study the Cobb-Douglas production function model was used to measure the appropriate management scale of farmland under different objectives in Shaanxi Province and analyze the regional differences. Under the two objectives, the appropriate management scale of the Loess Plateau was the largest in the three regions, followed by Qinba Mountains and Guanzhong Plain. Farmland area and quality were the main influencing factors for the appropriate management scale of farmland under the goal of maximizing the farmland yield, while the nonagricultural employment rate and farmland transfer rate were the main influencing factors under the goal of maximizing farmers’ profits. It is easy for Shaanxi Province to increase farmers’ profits, but more land needed to be transferred to increase farmland yield. These results suggest that in order to balance the goal of increasing yield and profit, the transfer of rural surplus labor should be promoted, and the nonagricultural employment rate should be improved. In Loess Plateau, restoring the ecological environment and enhancing the farmland quality. In Guanzhong Plain, avoiding urban land encroachment on farmland. In Qinba Mountains, developing farming techniques and moderately increasing the intensity of farmland exploit.

scholarly journals Soil carbon fractions and enzyme activities under different vegetation types on the Loess Plateau of China

2016 ◽  
Author(s):  
Haixin Zhang ◽  
Quanchao Zeng ◽  
Shaoshan An ◽  
Yanghong Dong ◽  
Frédéric Darboux
Keyword(s):  
Alkaline Phosphatase ◽  
Organic Carbon ◽  
Loess Plateau ◽  
Enzyme Activities ◽  
Soil Layer ◽  
Shaanxi Province ◽  
The Loess Plateau ◽  
Sucrase Activity ◽  
Carbon Fractions ◽  
Carbon Fraction

Abstract. Vegetation restoration was effective way of protecting soil erosion and water conservation on the Loess Plateau. Carbon fractions and enzyme activities were sensitive parameters for assessment of soil remediation through revegetation. Forest, forest steppe and grassland soils were collected at 0–5 cm and 5–20 cm soil layers in Yanhe watershed, Shaanxi Province. Urease, sucrase, alkaline phosphatase, soil organic carbon (SOC), microbial biomass carbon (MBC), easily oxidized organic carbon (EOC) and dissolved organic carbon (DOC) were measured. The results showed that carbon fraction contents and enzyme activities in the same soil layer followed the order that forest was higher than others. Carbon fraction contents and enzyme activities appeared that the 0–5 cm was higher than 5–20 cm soil layer. In addition, correlation analysis showed that urease activity was related to SOC, MBC, EOC and DOC at 0–5 cm layer; it was correlated with SOC, MBC and EOC at 5–20 cm layer. Sucrase activity had significant positive relationship with SOC, MBC and EOC. Alkaline phosphatase activity was related to EOC and DOC at 0–5 cm layer; it was correlated with MBC and EOC at 5–20 cm layer. The CCA reflected the relationship between sucrase activity and SOC. The contributions from the various forms of carbon fractions and enzyme activities as evaluated by the canonical coefficient of CV were on the order of SOC > DOC > MBC > EOC; sucrase > urease > alkaline phosphatase. Vegetation type was an important factor influencing the variation of soil enzyme activities and carbon fractions on the Loess Plateau.

scholarly journals Saprophytic microorganisms with potential for biological control of Botrytis cinerea on Geraldton waxflower flowers

2001 ◽  
Vol 41 (5) ◽  
pp. 697 ◽  
Author(s):  
D. R. Beasley ◽  
D. C. Joyce ◽  
L. M. Coates ◽  
A. H. Wearing
Keyword(s):  
Botrytis Cinerea ◽  
Mycelial Growth ◽  
Germ Tube ◽  
Conidial Germination ◽  
Pseudomonas Sp ◽  
Trichoderma Spp ◽  
Fusarium Sp ◽  
Flower Abscission ◽  
Germ Tube Elongation

Saprophytic bacteria, yeasts and filamentous fungi were isolated from Geraldton waxflower flowers and screened to identify potential antagonism towards Botrytis cinerea. Isolates from other sources (e.g. avocado) were also tested. Isolates were initially screened in vitro for inhibition of B. cinerea conidial germination, germ tube elongation and mycelial growth. The most antagonistic bacteria, yeasts and fungi were selected for further testing on detached waxflower flowers. Conidia of the pathogen were mixed with conidia or cells of the selected antagonists, co-inoculated onto waxflower flowers, and the flowers were sealed in glass jars and incubated at 20˚C. The number of days required for the pathogen to cause flower abscission was determined. The most antagonistic bacterial isolate, Pseudomonas sp. 677, significantly reduced conidial germination and retarded germ tube elongation of B. cinerea. None of the yeast or fungal isolates tested was found to significantly reduce conidial germination or retard germ tube elongation, but several significantly inhibited growth of B. cinerea. Fusarium sp., Epicoccum sp. and Trichoderma spp. were the most antagonistic of these isolates. Of the isolates tested on waxflower, Pseudomonas sp. 677 was highly antagonistic towards B. cinerea and delayed waxflower abscission by about 3 days. Trichoderma harzianum also significantly delayed flower abscission. However, as with most of the fungal antagonists used, inoculation of waxflower flowers with this isolate resulted in unsightly mycelial growth.

scholarly journals Evolutionary Characteristics and Trade-Offs’ Development of Social–Ecological Production Landscapes in the Loess Plateau Region from a Resilience Point of View: A Case Study in Mizhi County, China

2020 ◽  
Vol 17 (4) ◽  
pp. 1308
Author(s):  
Hang Zhang ◽  
Hai Chen ◽  
Tianwei Geng ◽  
Di Liu ◽  
Qinqin Shi
Keyword(s):  
Loess Plateau ◽  
Three Dimensional ◽  
Scientific Basis ◽  
Production Optimization ◽  
Evaluation Framework ◽  
The Loess Plateau ◽  
Plateau Region ◽  
Social Ecological ◽  
Trade Offs ◽  
The Social

Social-ecological production landscape resilience (SELPR) is a significant representation of the continuous supply capacity of landscape services. It is a quantitative assessment of the spatial-temporal evolution of SELPR under internal and external disturbances that provides a scientific basis for regional ecological environments and socio–economic development. Taking Mizhi County for the study of the Loess Plateau region, a three-dimensional (social system, ecosystem, and production system) SELPR evaluation framework was constructed. Data integration was performed using the watershed as the evaluation unit. This study quantitatively evaluated the spatial–temporal differentiation of the social–ecological production landscape (SELPs) subsystem’s resilience and the total SELPR in the study area and classified the areas from the three-system resilience combination level to achieve regional development trade-offs. The results were as follows: (1) In 2009–2018, the change in the social–ecological production landscapes pattern in Mizhi County showed a significant reduction in agricultural production landscapes, relatively stable social living landscapes, and an increase in ecological landscapes; (2) in 2009–2018, the SELPR increased by 12.38%. The spatial distribution of resilience was significantly different, showing a distribution pattern of high central and low surrounding areas; (3) the county’s watershed development zones were divided into five partitions: synergistic promotion areas, ecological restoration areas, social development areas, production optimization areas, and comprehensive remediation areas. The five types of zones have a certain agglomeration effect. In addition, the main obstacle factors affecting the SELPR of each zone are quite different. The key issues and development directions of different types of watersheds are also proposed in this paper.

Soil inorganic carbon stock under different soil types and land uses on the Loess Plateau region of China

CATENA ◽  
2014 ◽  
Vol 121 ◽  
pp. 22-30 ◽  
Author(s):  
Wen-Feng Tan ◽  
Rui Zhang ◽  
Hua Cao ◽  
Chuan-Qin Huang ◽  
Qin-Ke Yang ◽  
...  
Keyword(s):  
Loess Plateau ◽  
Carbon Stock ◽  
Inorganic Carbon ◽  
Soil Types ◽  
Land Uses ◽  
The Loess Plateau ◽  
Plateau Region ◽  
Soil Inorganic Carbon ◽  
Soil Inorganic

Change trends of temperature and precipitation in the Loess Plateau Region of China, 1961–2010

2012 ◽  
Vol 92-93 ◽  
pp. 138-147 ◽  
Author(s):  
Qi-xiang Wang ◽  
Xiao-hui Fan ◽  
Zuo-dong Qin ◽  
Meng-ben Wang
Keyword(s):  
Loess Plateau ◽  
The Loess Plateau ◽  
Plateau Region ◽  
Temperature And Precipitation

scholarly journals Hydrologic feasibility of artificial forestation in the semi-arid Loess Plateau of China

2011 ◽  
Vol 15 (8) ◽  
pp. 2519-2530 ◽  
Author(s):  
T. T. Jin ◽  
B. J. Fu ◽  
G. H. Liu ◽  
Z. Wang
Keyword(s):  
Loess Plateau ◽  
Large Scale ◽  
Regional Scale ◽  
Negative Relationship ◽  
Northern Region ◽  
Shaanxi Province ◽  
Stand Age ◽  
Mean Annual Precipitation ◽  
The Loess Plateau ◽  
Semi Arid

Abstract. Hydrologic viability, in terms of moisture availability, is fundamental to ecosystem sustainability in arid and semi-arid regions. In this study, we examine the spatial distribution and after-planting variations of soil moisture content (SMC) in black locust tree (Robinia pseudoacacia L.) plantings in the Loess Plateau of China at a regional scale. Thirty sites (5 to 45 yr old) were selected, spanning an area of 300 km by 190 km in the northern region of the Shaanxi Province. The SMC was measured to a depth of 100 cm at intervals of 10 cm. Geographical, topographic and vegetation information was recorded, and soil organic matter was evaluated. The results show that, at the regional scale, SMC spatial variability was most highly correlated with rainfall. The negative relationship between the SMC at a depth of 20–50 cm and the stand age was stronger than at other depths, although this relationship was not significant at a 5 % level. Watershed analysis shows that the after-planting SMC variation differed depending upon precipitation. The SMC of plantings in areas receiving sufficient precipitation (e.g., mean annual precipitation (MAP) of 617 mm) may increase with stand age due to improvements in soil water-holding capacity and water-retention abilities after planting. For areas experiencing water shortages (e.g., MAP = 509 mm), evapotranspiration may cause planting soils to dry within the first 20 yr of growth. It is expected that, as arid and semi-arid plantings age, evapotranspiration will decrease, and the soil profile may gradually recover. In extremely dry areas (e.g., MAP = 352 mm), the variation in after-planting SMC with stand age was found to be negligible. The MAP can be used as an index to divide the study area into different ecological regions. Afforestation may sequentially exert positive, negative and negligible effects on SMCs with a decrease in the MAP. Therefore, future restoration measures should correspond to the local climate conditions, and the MAP should be a major consideration for the Loess Plateau. Large-scale and long-term research on the effects of restoration projects on SMCs is needed to support more effective restoration policies. The interaction between afforestation and local environmental conditions, particularly water availability to plants, should be taken into account in afforestation campaigns in arid and semi-arid areas.

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