Chinese Journal of Agrometeorology

Revelation of Agrometeorology Learning From Climate Change 2014∶Impact， Adaptation，and Vulnerability

LIN Er da，XIE Li yong

2014, 35(04): 359-364. doi:10.3969/j.issn.1000-6362.2014.04.001

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Through the understanding of the assessment of impacts，adaptation and vulnerability in the Working Group II contribution to the IPCC Fifth Assessment Report（WGII AR5）in related chapters with agriculture，the current situation，research gapes and proposed priorities of future studies were analyzed. IPCC suggested that，climate change without adaptation is projected to mainly negatively impact production for local temperature increases of 2℃ or more above the late-20th century levels， projected impacts vary across crops and regions and adaptation scenarios， with about 10% of projections for the period 2030-2049 showing yield gains of more than 10%， and about 10% of projections showing yield losses of more than 25%， compared to the late 20th century. But the research gaps showed from the assessment of climate change impacts on Chinese agriculture mainly focus on：（1）the quantified assessment ability of sensitivity and vulnerability of agriculture system for climate change is still weak;（2）the direct and indirect impacts of climate change on agriculture were difficultly detected and attributed；（3）there were not enough of integration studies，did not quantify contributions of the nonclimate factors；（4）there were less adaptation implementation and experience summary， less cost/benefit analysis. The priorities of future studies suggested in these area：（1）revising and improving impact models of food production，establish regional and global credible integrated models of food system；（2）further understanding the influence degree of CO2 associate with O3 on crops，impacts of high and low temperature on crops and physiological thresholds of drought and flood；（3）developing several experiments and simulations of climate impacts and adaptation on food production related with different warming scenarios， including crops， animals，fishery，fruits and vegetables as production factors and nonproduction factors，e.g. processing，distributing，retailing and consume models.

Variation and Regional Difference of Annual Precipitation in the Upper Reaches of Hanjiang River During 1960-2011

REN Li li,YIN Shu yan,JIN Jun fang

2014, 35(04): 365-372. doi:10.3969/j.issn.1000-6362.2014.04.002

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Based on meteorological data from 31 stations in the upper reaches of Hanjiang river during 1960-2011,the spatio temporal characteristics and regional difference of 4 typical subareas(Hanzhong,Ankang,Shangzhou,Shiyan)was analyzed by using of linear regressive analysis,Mann-Kendall mutation test,spatial interpolation and wavelet analysisThe results showed that the spatial distribution of annual precipitation displayed a diminishing scale from south to north in the area The maxmum value was in Hanzhong and the minimum value was in Shangzhou The difference of annual precipitation among subareas decreased It was found that the change of precipitation mainly was affected by the monsoon climate and small scale geomorphic units, and the precipitation in spring and in winter displayed a diminishing scale from southeast to northwest, the precipitation in summer and in autumn displayed a diminishing scale from southwest to northeast;but there was slightly difference in the subareas The linear trend of annual precipitation was not significant in the area and subareas The linear decrease trend was significant in spring (P<0.05)Reduced precipitation of Shangzhou and Shiyan was the biggest contribution to the precipitation in spring The mutation test of annual precipitation was not significant,and the precipitation in spring and in autumn was less mutated significantly in the area The precipitation in Shangzhou and Shiyan was less mutated significantly in spring,and the precipitation in Ankang was less mutated significantly in autumn The first main period of annual precipitation and precipitation in spring and in autumn was 30y in the area and subareas,but the period of precipitation in summer and in winter was different in the area The change of precipitation could provide scientific reference for the normal operation of the middle route of SouthNorth water diversion project in the area

LAI and Light Transmittance Measurement of Isolated Vitex Shrub Using LAI2200 PCA

CHEN Jing ling，WANG Jing，WANG Qian，JIA Chang rong，KOU Yuan bo

2014, 35(04): 373-379. doi:10.3969/j.issn.1000-6362.2014.04.003

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Using the Plant Canopy Analyzer（PCA），authors nondestructively measured the leaf area index （LAIPCA）and diffuse noneinterceptance（DIFN） of 8 isolated Vitex negundo L. canopies. The light transmittance（τ）was measuredusing LI200SA sensor and LAIharvest of the 8 canopies was measured using harvesting method（total defoliation）.Then the correlation and deviation of LAIPCA and LAIharvest，also DIFN and τ， were compared. The results showed that （1）LAIPCA measured by LAI2200 PCA was closely related to LAIharvest obtained with the harvesting method，passed through the significant test at 0.01 reliability. LAIPCA measured by LAI2200 PCA was 2.57% higher than that obtained with the harvesting method （total defoliation），which indicated that LAI2200 had small deviation when used to measure LAI of isolated forest canopy.（2）DIFN measured by LAI2200 PCA closely related to the light transmittance（τ）measured by LI200SA sensor（P<0.01）. It indicated that LAI2200 PCA can be used to measure vitex shrub isolated canopy LAI and light transmittance replacing total defoliation method. The paper demonstrated isolated forest canopy analyzing method，which widely presents in the practice of forestry production.

Simulation Study on Evapotranspiration of Rice Paddy in the Sanjiang Plain

JIA Zhi jun，JI Xing jie

2014, 35(04): 380-388. doi:10.3969/j.issn.1000-6362.2014.04.004

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Based on the eddy covariance and microclimate observed data from 2005 to 2007，the simulating accuracy of evapotranspiration（ET）with the Penman，PenmanMonteith（PM）and PriestleyTaylor（PT）models of rice paddy from May to October in the Sanjiang plain was analyzed The results showed that the simulated value of ET by using the Penman model with conventional patters was significantly higher than that of measured ones，with average 103.5%. However the value of ET by using PM and PT model was accurate，with mean bias error （MBE）0.26mm·d-1and 0.02mm·d-1，and root mean square error（RMSE）0.68mm·d-1and 0.71mm·d-1，respectively. There was significant positive correlation between crop coefficients（Kc）of rice paddy and leaf area index（LAI）by using the Penman and PM models，and there was positive correlation between α value and LAI，vapor pressure deficit（VPD）and wind speed（WS），even extreme significance with VPD and WS under the PT model. The accuracy of the Penman model was improved obviously after modified by linear regression equation，with MBE 0.28mm·d-1and RMSE 0.64mm·d-1， respectively，and modeling efficiency（ME）changed to 0.75 from a negative value. But the accuracy of PM and PT model was not improved. The simulated value was not significant difference among three models by using variance analysis，which indicated that the simulating accuracy of three models to evapotranspiration in Sanjiang plain was similar. In conclusion，both of PM and PT model was suitable for estimating the ET of rice paddy in the Sanjiang plain whether the Kc and α were modified or not，while the Penman model was suitable only when the Kc was modified．

Survey of Soil Available Copper and Available Zinc Contents on Herbal Field and Food crop Field in Anguo City

ZHAO Jiao jiao，LIU Wen ke

2014, 35(04): 389-394. doi:10.3969/j.issn.1000-6362.2014.04.005

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Soil samples were taken from three layers（0-20，20-40，40-60cm）of herbal fields and foodcrop fields in 10 villages of 4 townships in Anguo city，Hebei province，in May 2012.The available Cu and available Zn of soils were determined to clarify the status and their difference of the contents of available Cu and available Zn between two types of fields with various utilization patterns under current cultivation conditions. The results indicated that contents of available Cu and available Zn of herbal field soils were 0.34-1.21mg·kg-1 and 0-10.49mg·kg -1， respectively， and available Cu and available Zn of food crop field soils were 0.27-2.11mg·kg-1 and 0-3.44mg·kg-1， respectively. The results of ttest showed that soil available Cu and available Zn contents between herbal fields and foodcrop fields were not significant difference. However，soil available Cu of foodcrop fields were slightly richer，but available Zn were relatively lack. Soil available Zn of surface layer（0-20cm）in herbal fields and foodcrop fields were remarkably higher（P＜0.01）than the other two layers（20-40，40-60cm），but the difference of soil available Cu contents were not significant between three soil layers. The data showed that soil available Cu and available Zn contents among soil samples were great. Contents of soil available Cu and available Zn in herbal fields and foodcrop fields were similar，and contents of soil available Cu were in medium level to meet the demand of crop growth. However，available Zn contents were lack in herbal fields and foodcrop fields according to the soil trace element classification standard. So copper and zinc micronutrient fertilizer should be used increasingly to improve the quality and yield of herbal under current cultivation.

Effects of Simulated Warming on Seed Emergence and Seedling Growth of C3/C4 Plants

CHEN Yu qi，YANG Jie,WANG Ping ping,SONG Bing yu

2014, 35(04): 395-402. doi:10.3969/j.issn.1000-6362.2014.04.006

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In order to investigate the response of seed germination and seedling growth of C3 and C4 plants to climate warming,authors regarded two herb species Stipa bungeana and Bothriochloa ischaemum as well as two small semishrub species Artemisia frigida and Kochia prostrate as objects,which are separately coexisting in Inner Mongolia steppe.OTC was designed to simulate warming to observe the seed emergence and seedling growth,biomass accumulation and allocation of four plants.The results showed that:（1）simulated warming significantly increased seed emergence percentage,emergence rate and decreased seedling mortality rate of C4 species（Bothriochloa ischaemum and Kochia prostrata）relative to C3 species（Stipa bungeana and Artemisia frigida）（P＜0.05）.（2）The seedling growth of different photosynthetic type responded to simulated warming differently: warming significantly increased the seedling height of C3 plants（P＜0.01）while the leaf length and leaf area of C4 plants（P＜0.05）.（3）Simulated warming had little effect on biomass accumulation of C3 seedlings but an obvious promotion of aboveground biomass accumulation of C4 seedlings.（4）Warming increased the root biomass allocation of Artemisia frigida（C3）（P＜0.05）,but had no effect on the biomass allocation of other three plants. Based on the results we can predict that the seed emergence and seedling growth of C4 species will benefited from the air temperature rise of 2℃ in the future.The results can provide the basis for further research of the composition,distribution and adaptability of C3/C4 species under climate change.

Effects of Mulching Models on Soil Temperature and Yield of Winter Wheat in Rainfed Area

CHEN Yu zhang， CHAI Shou xi， FAN Ying dan， CHENG Hongbo， HUANG Cai xia， TAN Kai min， CHANG Lei， YANG Chang gang

2014, 35(04): 403-409. doi:10.3969/j.issn.1000-6362.2014.04.007

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In order to find out the effects of different mulching models on soil temperatures in the 5-25cm soil layer and grain yield in a semiarid rainfed area of northwestern China， the field experiments with different mulching material and time were conducted from October in 2011 to August in 2012. The field experiments was comprised of the following 7 treatments: mulching plastic film applied in summer and soil placed on the top of the film at 1cm deep （T11）， similar to T11 but plastic film applied in autumn （T12）， reused the old film mulching after the first harvest of winter wheat （T13）， the combination of T11 to field returned wheat straw（T14）， mulching 5cm long of wheat straw to the field in summer （T21）， mulching whole wheat straw in summer （T22）， and an unmulched control （CK）. The results showed that:（1）compared to CK， both plastic mulching and straw mulching increased soil temperatures before the jointing stage of wheat but decreased soil temperatures after the jointing stage（P＜0.05）. The increasing magnitude of soil temperature plastic film mulching was greater than straw mulching， whereas the decreasing magnitude of soil temperature was just contrary. Among the mulching treatments evaluated in the study， T13 treatment increased soil temperatures most and higher than CK 0.24℃， whereas T21 decreased most and lower than CK 0.68℃ in 5-25cm soil layer during the whole growth period of winter wheat.（2）Soil warming effects due to mulching mainly appeared in the morning， but cooling effects were mostly at the noon and at dusk.（3）Compared to CK， any of mulching treatments increased the grain yield（5.0%-29.0%，P＜0.05）， but the yield of plastic film mulching increased higher than that of straw mulching， Yield of winter wheat increased was mainly caused by being increased spike numbers and 1000grain weight. In conclusion， both plastic film mulching and straw mulching could regulate soil temperature and enhance the grain yield in the whole growth period of winter wheat， but T11 has the most crop productivity in a semiarid rainfed area of northwestern China.

Effects of Low Temperature Stress on the Photosynthetic Capacity and Yield Components of Early Rice at the Spikelet Differentiation Stage

ZHANG Jin en， NIE Qiu sheng， LI Ying chun， TIAN Jun， WANG Shang ming, LU Kui dong

2014, 35(04): 410-416. doi:10.3969/j.issn.1000-6362.2014.04.008

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Experiments were conducted under artificial climate chambers conditions to assess the photosynthetic responses and photosynthetic capacity recovery process of early rice （Oryza sativa L.，Jinyou458） to low temperature stress （T1 and T2， subjected to 17°C and 15°C for 3 days） at spikelet differentiation stage， by determined gas exchange and light response parameters， SPAD value， yield components. The results indicated that，（1）Pn， Gs， Ci， Tr of T1 and T2 were decreased significantly compared with CK （control group， natural condition）. Pn of T1 recovered 3 days after stress， while T2 recovered 6 days later. However， Pn and Gs was decreased significantly on the 17th day and 32nd day after stress， while Tr was increased significantly. （2）Light response capacity of T1 enhanced 0-6 days after stress， while T2 was decreased significantly. By the 6th day， T2 was recovered to the same level of CK， but Pm， AQY and Ik of T1 and T2 were decreased significantly by the 32nd day. （3）SPAD value of T1 and T2 were decreased significantly. T1 was recovered to the same level of CK by the 3rd day， while T2 recovered by the 6th days. （4）The grain No. per panicle， ripening rate， thousand grain weight， and theoretical yield of T1 and T2 were decreased significantly， while unfilled and abortive grain rate were increased， which leaded to yield reduction rate of 25%. Obviously， low temperature stress at spikelet differentiation stage had negative effects on gas exchange activity and maximum photochemical capacity of early rice， thought recovered to some degree later， but the negative effects were irreversible for long， which leaded to lower yield. The results could support scientific foundations for meteorological disaster impact assessment and meteorological disaster indexes development.

Effects of Light on Leaf Physical and Chemical Property and Aromatic Components Content of Flue cured Tobacco

YANG Xingyou， LIU Guoshun， YU Xiangwen， XING Xiaojun， QIN Yanqing，JIN Dongmei

2014, 35(04): 417-422. doi:10.3969/j.issn.1000-6362.2014.04.009

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In order to study the relationship between light and quality of tobacco leaf， the potculture experiments were conducted in intermediate altitude area of Sichuan province. Shadingcontrolled experiment were conducted to achieve five different irradiances of 100%（T1），60%（T2），40%（T3），20%（T4）and 10% （T5）of full sunlight， the differences of leaf structure and the physics and chemistry characteristic and aromatic components of fluecured tobacco under different light conditions were studied. The results indicated that tobacco leaves thickness， rate of palisade tissue and spongy tissue thickness of leaves palisade tissue and spongy tissue reduced when light intensity decreased. The per leaf weight，thickness，weight per unit leaf area，leaf density and sugar content of flue cured tobacco were decreased under low light intensity. However，the content of stem ratio，nicotine，total nitrogen，potassium，chlorine，lutein，carotenoid and neutral aroma constituent increased. The research results provided a theoretical basis for tobacco planting in high and intermediate altitude area and the mechanism of formation of tobacco characteristics.

Analysis on Climatic Maize Yield and Its Sensitivity to Climate Change in Northeast China

LI Hui， YAO Fengmei， ZHANG Jiahua，HAO Cui

2014, 35(04): 423-428. doi:10.3969/j.issn.1000-6362.2014.04.010

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The meteorological stations with continuous meteorological data and maize yield data in Northeast China during 1981-2009 was divided into 4 zones according to temperature （Tmean）， sunshine hours （SH） and precipitation （P）， in which the climatic maize yield was calculated by using of first differences method. The sensitivity of maize yield to climate change was analyzed by using of multiple regression method. The results showed that the climatic maize yield decreased though actual maize yield increased during 1981-2009. The sensitivity of climatic maize yield to， in climatic type I zone， Tmax， AT， DTR （daily temperature range） and SH was high， with the standard coefficients were-1.244， 1.484，-0.655 and 0.502 respectively. In climatic type II zone， the sensitivity of climatic maize yield to Tmin， AT， DTR and SH was high， with the standard coefficients were 1.325，-1.739，-0.272 and-0.515 respectively. In climatic type III zone， the sensitivity of climatic maize yield to Tmax， AT， P and SH was high， with the standard coefficients were-2.171， 3.450， 0.235 and 0.493 respectively. In climatic type IV， the sensitivity of climatic maize yield to Tmin， AT， P and SH was high， with the standard coefficients were 0.88，-1.014， 0.329 and 0.256 respectively. Climatic maize yield was sensitive to AT in all types zones， was sensitive to Tmin in high temperature zones， was sensitive to TmaX in moderate and low temperature zones. Climatic yield was sensitive to P and SH in high precipitation zones， and was sensitive to DTR and SH in moderate and low precipitation zones.

Determination of Optimum Sowing Date and Analysis of Climate Risk for EarlyRice in Hubei Province

CAO Xiuxia， WAN Suqin， WU Ming

2014, 35(04): 429-433. doi:10.3969/j.issn.1000-6362.2014.04.011

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Based on daily meteorological data from 4 representative stations across the main early rice growing regions in Hubei province， including Wuhan， Jingmen， Jingzhou and Huangshi. The safe sowing date for early rice under different guaranteed rates during the earlier 30 years （1953-1982） and the latest 30 years （1983-2012） were detected and discussed， the optimum sowing date was comprehensively determined by comparing the potential yield simulated by using of CERESRice model with different sowing dates， as well as the corresponding risk of seedling rot indicated by a climate index. The results showed that the safe sowing dates under different guaranteed rates in 1983-2012 advanced 2-7d than that of in 1953-1982. If early rice was sowed during 24th March to 1st April in Wuhan， 26th March to 4th April in Jingmen， 25th March to 3th April in Jingzhou， 23th March to 31th March in Huangshi， which was under their 50%-80% guaranteed rates of the latest 30 years respectively， there would be a relative low risk of seed rot and seedling blight， and high yield.

Teleconnection Analysis Between Spring Frost Damage on Tea in Zhejiang Province and Sea Surface Temperature in Pacific

WU Yang，JIN Zhifeng，YE Jiangang，YANG Zaiqiang，HU Bo，LI Renzhong

2014, 35(04): 434-439. doi:10.3969/j.issn.1000-6362.2014.04.012

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Based on the daily minimum temperature of 68 stations in Zhejiang during 1971-2013， the spring frost damage index defined. The spatial and temporal evolution of spring frost damage was analyzed by using Kriging interpolation and statistical methods. The teleconnection between the spring frost damage days and Pacific SST （sea surface temperature） during the same period was also studied by correlation analysis and SVD. The results showed that the northern part of Zhejiang was affected more seriously by the spring frost damage， especially the north west of Zhejiang， the southern Zhejiang and Jinhua Quzhou basin were the less influenced regions. The spring frost damage occurred frequently before mid1990s， and declined since late1990s.The spring frost damage index was significantly connected with the Southern Pacific SST over （130°-170°W，18°-28°S） in the former year， which could be a clue to the spring frost damage forecast in Zhejiang.

Shortterm Forecast Models for Occurrence Grades of Sogatella furcifera（Horvth）Based on Characteristics of Atmospheric Circulation

BAO Yunxuan，TIAN Lin，XIE Xiaojin，LU Minghong，JIANG Yuying

2014, 35(04): 440-449. doi:10.3969/j.issn.1000-6362.2014.04.013

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The reanalyzed meteorological grid data from NCEP （National Center for Environment Predicting in USA） in 1979-2011 and the pentad lighting catches of Sogatella furcifera（ white backed plant hopper，WBPH） in the rice growing regions of the middle and lower reaches of the Yangtze river were collected to discuss the influence of the atmospheric circulation characteristic variables on the immigrations of WBPH. After the analysis of the correlations between the immigration amount of WBPH and the main atmospheric circulation characteristic variables， a method of Back Propagation Neural Network was used to establish the shortterm forecast models of WBPHs occurrence grades during the beginning periods of immigration， the peak periods of migration northward， the peak periods of migration southward and the ending periods of immigration for 13 plant protection stations in the middle and lower reaches of the Yangtze river. The results showed as follows: （1） there were most significant correlations between the immigration amount of WBPH and the area index of the western Pacific Subtropical High （IA）， the western ridge point index of the western Pacific Subtropical High （IW）， the westerly strength index （IEARW） and the East Asia major trough index （H500） on the isobaric surface of 500hPa in the preceding pentad respectively. Among these correlations， the correlation between the immigration amount of WBPH and IEARW was negative and the correlations between the immigration amount of WBPH and IA， IW and H500 were positive. The correlation between the immigration amount of WBPH and IW was 0.397 as the least value but the correlation coefficients between it and IA， IEARW and H500 were larger than 0.78. （2） There were significant positive correlations between the immigration amount of WBPH and the geopotential height （hgt）， vertical velocity （omega）， zonal wind speed （uwnd） and meridional wind speed （vwnd） on the isobaric surface of 850hPa in the preceding pentad respectively. Among these correlations， the correlation coefficient between WBPHs immigration amount and hgt was 0.354 as the least value but the correlation coefficients between it and omega， uwnd and vwnd were larger than 0.8. （3） The atmospheric circulation characteristic variables of significant correlation between them and the immigration amount of WBPH were selected as the predictors. After the WBPHs immigration amounts were divided into 5 occurrence grades， 4 forecasting models of WBPHs occurrence grades during the beginning periods of immigration， the peak periods of migration northward， the peak periods of migration southward and the ending periods of immigration based on the method of Back Propagation Neural Network were established and the extension examination accuracy rates of these models stabled above 80%. Therefore， these models were proved to be available for the shortterm forecast of WBPH pendant occurrence grades in the middle and lower reaches of the Yangtze river. The results were positive significant to reveal the influence rules of meteorological factors on WBPHs immigration， to predict the WBPHs occurrence degrees， and to prevent or control the WBPH harmness timely and effectively.

Drought Disaster Evaluation and Temporal Spatial Characteristics of Late Rice in South China

WANG Chunlin，TANG Lisheng，XIE Wu，DUAN Hailai，LIU Wei

2014, 35(04): 450-456. doi:10.3969/j.issn.1000-6362.2014.04.014

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Using yield and growth period data of 174 counties in South China（Guangdong and Guangxi province）， drought index of each growth period of late rice was calculated by daily meteorological drought indicator（DI）， drought disaster evaluation model was constructed and temporal spatial characteristics of the drought disaster was analyzed in the paper. The results showed that，（1）average drought year frequency of late rice in recent 30 years （1981-2010） in South China was 7.1%， where light drought accounts for main part， medium and above almost never. Mean yield reduction rate of drought was 0.66%. Drought disaster mainly occurs in seedling to 3leaf stage and milkripe to mature stage of late rice. （2）Spatial distribution of late rice drought frequency and yield reduction rate were high in west and low in east in South China. Relative high incidence areas locate in northeast Guangxi province， where the drought frequency was above 10% and the yield reduction rate was more than 1%. （3）The driest 6 years of late rice in recent 30 years in South China were 1992， 1990， 1989， 1991， 2009 and 2004. Considering the region as whole， statistically significant lighten trend of drought was observed in seeding to 3leaf stage of late rice during recent 30 years， nevertheless， there was no statistically significant trend of drought was observed in the whole growth period and milkripe to mature stage of the late rice. （4）Stations that drought of the whole growth period of late rice tend to intensify account for 69%， among which 3.4% stations were statistically significant （above 0.1 level）. Stations that drought of the milkripe to mature stage tend to intensify account for 94.8%， among which 36.2% stations were statistically significant， located mainly in Guangxi and north Guangdong. Stations that drought of the seeding to 3leaf stage tend to lighten account for 75.9%， among which 16.1% stations were statistically significant， located mainly in the area from Chongzuo to Wuzhou of Guangxi province. The study provides scientific basis for drought disaster mitigation， climate change adaptation policy making and environment diplomacy.

Real Time Forest Fire Warning System Based on the Forest Fire Danger Index

GUO Yan ru，WANG Kai song，ZHANG Yan，CAO Meng，WEN Wan yu，WU Gao jie，GUO Zhi hua

2014, 35(04): 457-462. doi:10.3969/j.issn.1000-6362.2014.04.015

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Considering the Renshou region in the Sichuan province as an example，authors showed the process and effect of the operation of such a system. Using forest fire danger index instruments to monitor forest fire risk grades in real time，a real time forest fire warning system was designed using ArcGIS Engine10 as the platform and using SQL Server 2005 as the database.The proposed system consists of three processes：selecting the appropriate locations to install the forest fire danger index instruments，calculating the fire danger index and fire risk grade， and plotting thematic maps and information issues.Owing to such a system，fire risk grades and their spatial distribution can be displayed on electronic maps and datasheets.The proposed system was tested in Renshou region in the Sichuan province，and the results showed that the forest fire warning system can predict forest fire risks rapidly and in real time;thus allowing us to adopt preventative or protective measures against potential fires.

Study on Chilling Injury Indices of Pitaya at Flowering and Fruit Stage

YUAN Xiao kang，GU Xiao ping，YANG Zai qiang，LONG Xian ju，LIANG Ping

2014, 35(04): 463-469. doi:10.3969/j.issn.1000-6362.2014.04.016

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In order to determine the chilling injury indices of pitaya，6year trees of Chinese pitaya variety “Zihonglong” （Hylocereus polyrhizus Briton & Rose）at flowering and fruit stage were used as material. Simulating temperature in the low temperature process，4 different dynamic intensity and duration of low temperature were set from September to October in 2012.The minimum temperature of experiment was 4，2，0 and-2℃ respectively and continued 1d，3d and 7d，taking the basis experiment minimum temperature 20℃ as the control（CK）.In each experiment，relative electrical conductivity（REC），MDA content，SOD activity and soluble protein content of pitaya branch were determined，and morphological change was observed at the same time.The results showed that when the daily minimum temperature（Tmin）varied from 2 to 4℃ and continued more than 3d or Tmin varied from 0 to 2℃ and continued 1-3d， pitaya branch sufferred slight chilling injury（grade 1），when Tmin varied from 0 to 2℃ for more than 4d or Tmin varied from-2 to 0℃and continued 1-3d，pitaya branch sufferred moderate chilling injury（grade 2），when Tmin varied from-2 to 0℃ and continued more than 4d，pitaya branch sufferred severe chilling injury（grade 3），when Tmin was less than-2℃， pitaya branch sufferred extra severe chilling injury（grade 4）.These indices were used to verify the pitaya chilling injury degree in Luodian county and Chuzhenfeng county in Guizhou province in March 2012.After a low temperature process，the results were in accordance with the truth.The results could provide scientific basis for chilling injury early warning，prevention and planting division of pitaya.

Vegetation Cover Change and Its Relationship Between Climate and Human Activities in Ordos Plateau

LI Xiao guang,LIU Hua min,WANG Li xin,ZHUO Yi

2014, 35(04): 470-476. doi:10.3969/j.issn.1000-6362.2014.04.017

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