Affecting Rice Production Research Articles

The climatic characteristics of Najaf province and their relationship to the growth of the bush affecting rice production

Rice is a food crop that is considered one of the mainstays of food security, so all countries seek to provide it to meet the needs of their growing population with high living standards, which increases the demand for it, and Iraq was considered one of the countries exporting rice until the end of the last century, after which its production began to decrease due to water scarcity. The problem of the spread of weeds in rice fields, which causes huge losses in its production, is exacerbated, amounting to (63%). Therefore, work must be done to increase its production by combating what grows from the bushes in the rice fields.

ANALYSIS OF EFFICIENCY ON RICE FARMING

The research aims to analyze the efficiency on rice farming business and factors that affect rice production associated with participation in farmer groups. The research was conducted in Senduro Village, Senduro District, Lumajang Regency. Analysis method in this research included revenue, cost and efficiency on rice farming, as well as multiple regression of production function. The results show that there are different performance among farmers who are member and non-member of farmer’s group. Productivity to the farmers who are member of farmer group was 8.776 tons per hectare and non-member was 7.275 tons per hectare. Farmers in the group gained higher revenue (IDR 37.74 million per hectare) compared to non-member (IDR 31.28 million per hectare). Production cost to the farmers who are member of farmer group reached IDR 12.69 million per hectare and non-member was IDR 12.55 million per hectare, with efficiency values (R/C) 2.97 and 2.49, respectively. Farmers who become member of the group adhered better farming practices which use more efficient fertilizer, more intensive irrigation and more seeds. Rice production is significantly affected by land size and the group membership. Ten percent increasing in land size would increase production by 2.4 percent. However, for the other factors, i.e, age, education, number of family member, seeds, manpower and fertilizer had no significant effect on rice production.

Efisiensi Alokasi Penggunaan Faktor Produksi pada Usahatani Padi di Kecamatan Wirosari, Kabupaten Grobogan

The purpose of this study was to analyze the influence factors of rice production and analyze economic efficiency of production factors usage of rice in the Wirosari District, Grobogan Regency. The research was conducted from October to November 2016 in Wirosari District. The method used in the study was survey method . To determine research location this study used purposive method while the respondent was chosen using simple random sampling with the number of respondents were 60 farmers . Data were analyzed by multiple linier regression with Cobb-Douglas function and calculation of economic efficiency. The result showed that the production factor affecting rice production was seed and NPK fertilizer. The usage of NPK fertilizer had not been economically efficient yet. Whilst the usage of seed was economically inefficient.

An Analysis of Women Farmers in Rice Production in Donga Local Government Area of Taraba State

The study focuses on Analysis of Women Farmers in Rice Production in Donga Local Government Area of Taraba State. A total of 120 Questionnaire were collected and subjected to descriptive statistical analysis. The study used purposeful sampling technique to choose two (2) wards out of the ten (10) political wards in Donga Local Government Area of Taraba State. The two (2) wards were Akate and Asibiti wards. Also, random sampling was used to distribute the questionnaires among the respondents in the two (2) wards selected. In each of the wards, twelve (12) households were randomly selected and five (5) questionnaires were distributed to each of the household. The Chi-Square(X2) test was used to ascertain the relationship between the factors affecting rice production by women rice farmers in Donga L.G.A of Taraba State. The study reveals that 41.7 percent of respondents purchase farmland for the cultivation of rice. And 40 percent obtain credit facilities from cooperative societies. Also, 42.5 percent of the respondents consider inadequate finance as the major factor affecting rice production by women farmers in Donga L.G.A of Taraba State. All stakeholders must give all necessary assistance to women farmers involve in rice production.

Influence of Climate Factors on Rice Yields in Cambodia

Temperature and precipitation have been known as the key determinant factors to affect rice production in climate change. In this study, the relationship between climate variables and rice yields during 1993–2012 in Cambodia was analyzed and evaluated. The Ordinary Least Squares analysis was applied to examine the relationship of three climate variables (TCV) including maximum temperature, minimum temperature and rainfall against seasonal rice yields. By this period, a remarkable increasing trend of annual temperature was observed whilst rainfall was not significantly changed. The TCV explains approximately 63% and 56% of the variability of rice yields in wet and dry seasons, respectively. It is found that in Cambodia, non-climate factors such as fertilizers, water, cultivars, and soil fertility cause 40% variation to rice yields, whereas the remaining 60% can be influenced by climate variability. The levels of temperature difference (LTD) between maximum and minimum temperatures of the wet season (WS) and dry season (DS) were 7.0 and 8.6 ^oC, respectively. The lower value of LTD may cause the reduction of rice in WS (2.2 tons/ha) as compared to that of DS (3.0 tons/ha). Rice yield has increased 50.5% and 33.8% in DS and WS, respectively, may due to the improvement of rice cultivation practices in Cambodia such as the better use of fertilizers, pest and weed control, and irrigation, and more effective rice cultivated protocol, as the increased trend of temperature may detrimentally affect rice yield. The breeding of heat and drought tolerance rice varieties and development of irrigation system are effective to reduce the negative influence from climate change to rice production in Cambodia.

EFISIENSI TEKNIS USAHATANI PADI TADAH HUJAN DI KAWASAN PERBATASAN KABUPATEN SAMBAS DENGAN PENDEKATAN STOCHASTIC FRONTIER FUNGSI PRODUKSI (KASUS DI DESA SEBUBUS, KECAMATAN PALOH)

Development of rice for food self-sufficiency in the border region of Sambas regency is quite prospective. However, in the District Paloh rice productivity is still relatively low, allegedly due to inefficiency in the use of inputs. The aim of this study was to analyze the efficiency and income of rice farming in the village of Sebubus, Paloh district. The research method used was stohastic frontier of production function with OLS and Maximum likelihood (MLE). The study was conducted in the village Sebubus, District Paloh between May - June 2014. Sampling was done with Proportionate Stratified Random Sampling. The data used was the cross section data obtained from interviews of 120 rice farmers. The Stohastic frontier of production function analysis was performed using the Cobb-Douglas models. The results showed that land, N fertilizer and K fertilizer significantly affected rice production at 95% confidence level. The results also showed that rainfed rice paddy was relatively efficient technically (mean efficiency of 0,81). Age of farmers was a source of technical inefficiency that significantly could improve technical efficiency. Characteristics of farmers such as age, education and experience could help farmers improve their technical efficiency of rice production. Rainfed rice farming in the village Sebubus was relatively favorable (profit of USD 4,099,582.50) and viable (the value of R/C ratio above 2,84 cash costs and the value of R/C ratio on total cost of $ 2,29).

Factors that Influence Rice Production and Technical Efficiency in the Context of an Integrated Crop Management Field School Program

This research estimates the effect of production input on rice production and the effect of socio-economic factors on the technical efficiency of rice farms in the program of the Integrated Crop Management Field School (ICMFS). Data were collected from 78 rice farmer household heads from two randomly chosen villages in Indonesia. The results show that seed, fertilizer, pesticide and labor significantly positively affect rice production. Socio-economic factors such as farmer age, education and experience, the number of household members and the frequency of visiting the ICMFS field laboratory had significant positive effects on the level of technical efficiency. Thus, the ICMFS, by continuing to increase ICMFS program to the people of rural areas and by taking into account socio-economic status of farmers, can improve rice farming production and efficiency.

Technical Efficiency and Its Determinants of Rice Production in Cambodia

The present study aims to measure the technical efficiency and establish core factors affecting rice production in Cambodia. A four‐year dataset generated from the central government document “Profile on Economics and Social” of 25 entire provinces between 2012 and 2015 and the stochastic production frontier model (SFA) was applied. The results indicated that the level of output (quantity) of Cambodian rice production varied according to the different level of capital investment in agricultural machineries, total rice actual harvested area, and technical fertilizer application within provinces. Furthermore, evidence revealed that the overall mean efficiency of rice production is 78.4%, which implies that there is still room to further improve technical efficiency given the same level of inputs and technology. More importantly, the findings revealed that irrigation, production techniques and amount of agricultural supporting staff are the most important influencing factors of rice production’s technical efficiency in Cambodia. In conclusion, the present study strongly recommends the development of irrigation systems and good water management practices to be considered and bring about more effective actions by the central government as well as related agencies for improving rice production in Cambodia in addition to capital investment and improving technical skills of supporting staff and rural farmers.

PHYSIOLOGICAL AND GENETIC PERFORMANCE OF SOME RICE GENOTYPES GROWN IN MEDIUM AND HIGH SALINITY SOILS

Salinity is a common abiotic stress that seriously negatively affects rice production in the world. The investigation was carried out at the Experimental Farm of El-Sirw Agricultural Research Station, Damietta governorate, Egypt to investigate the effect of soil salinity levels (6 and 11 dS m-1) on the morphological, leaf chemical constituents and yield traits and phenotypic and genotypic parameters of twelve rice genotypes (Giza 177, Giza 179, Giza 182, Egyptian Jasmine, GZ 10303, GZ 10305, IET 1444, GZ 10286, GZ 9399, GZ 9461, PLGF101 and Egyptian Hybrid 1) during 2014 and 2015 seasons. The obtained results could be outlined as following: 1- The high level of salinity negatively affected growth parameters (leaf area index, dry matter production and chlorophyll content) and yield related characteristics (heading date, plant height, number of tillers hill-1, number of panicles hill-1, panicle length, number of filled grains panicles-1, 1000-grain weight, grain yield, biological yield and harvest index) in both seasons. It was detected that increasing salinity sharply decreased rice grain and biological yields with reduction percent amounted to 43.66 and 33.81 % for grain yield and biological yield, respectively. On the other side, increasing salinity significantly increased proline content, Na+ % and Na+/ K+ ratio while decreased K+ % in rice leaf. 2- The different genotypes were significantly varied among each other in their growth and yield. Egyptian Hybrid 1 surpassed other tested genotypes in growth parameters, number of tillers and panicles hill-1, panicle length, number of filled grain panicle-1 and grain and biological yields ha-1 in both seasons as compared with the other rice genotypes. On the contrary, the rice genotype of Giza 179 had the lowest unfilled grains panicle-1. The salt tolerant rice genotypes (Egyptian Hybrid 1, Giza 179, GZ 9399, GZ 9461 and IET 1444) had higher proline content and potassium % and lower Na+ and Na+/ K+ ratio, while the sensitive salt rice genotypes showed opposite pattern. 3- The interaction between the tested rice genotypes and salinity levels was significant for studied traits in both seasons. In general, Egyptian Hybrid 1 genotype was superior for the most growth and yield traits when it was grown on medium or high salinity levels followed by GZ 9399 and GZ 9461 genotypes. However, PLGF 101 genotype had the worst performance followed by GZ 10303 and Giza 177 rice genotypes. It could be concluded that Egyptian Hybrid 1 genotype had considerable affinity for withstanding salinity stress to tested levels under the experimental salinity conditions. The maximum reduction for grain yield (65.94 and 66.83%) was produced by planting Giza 177 and Giza 182 genotypes in the first and second seasons, respectively. However, the lowest reductions (23.59 and 18.85%) were obtained by growing Egyptian Hybrid 1 and GZ 9399 in the first and second season, respectively. 4- The phenotypic coefficient of variability (PCV) was slightly higher than those of genotypic coefficient of variability (GCV) for all studied traits of the twelve rice genotypes grown under the salinity levels. The value of GCV % was varied from 21.44 to 41.93 but in PCV% ranged from 23.68 to 52.99 for grain yield. In most characteristics the increasing salinity level raised the contribution of environmental variability in phenotypic variability. High heritability (H2%) estimates in broad sense were detected for most studied traits.

Effect of drought stress on morpho-physiological traits in some traditional rice cultivars of Kokrajhar district, Assam, India

Water status is one of the critical factors affecting rice production. Rice cultivars tolerant to drought stress at the vegetative stage were selected. Six traditional rice cultivars of Kokrajhar district, Assam, namely, Sali, Bora, Ahu, Malsira, and two variety of Jaha i.e.; white and black were included in this study. The germination index, plant growth, root architecture, leaf rolling, leaf death and leaf relative water content in plants subjected to drought stress for 0, 7, 14 and 21 days were recorded. Based upon the levels of water stress tolerance, three groups of rice cultivars were recognized, as follows: highly drought-tolerant, moderately drought-tolerant and drought-sensitive cultivars. The Joha (white) rice cultivar was considered to be a highly drought-tolerant cultivar. The moderately drought-tolerant cultivars included Joha (black), Ahu, Sali and Bora. The Malsira cultivar was considered sensitive to drought.

Sea level rise impacts on rice production: The Ebro Delta as an example

Climate change and sea level rise (SLR) are global impacts threatening the sustainability of coastal territories and valuable ecosystems such as deltas. The Ebro Delta is representative of the vulnerability of coastal areas to SLR. Rice cultivation is the main economic activity in the region. Rice fields occupy most of the delta (ca. 65%) and are vulnerable to accelerated SLR and consequent increase in soil salinity, the most important physical factor affecting rice production. We developed a model to predict the impacts of SLR on soil salinity and rice production under different scenarios predicted by the Fifth Assessment Report of the Intergovernmental Panel on Climate Change by coupling data from Geographic Information Systems with Generalized Linear Models. Soil salinity data were measured in agricultural parcels and rice production from surveys among farmers. The correlation between observed and soil salinity predicted values was high and significant (Pearson's r=0.72, P<0.0001), thus supporting the predictive ability of the model. Soil salinity was directly related to distances to the river, to the delta inner border, and to the river old mouth, while clay presence, winter river flow and surface elevation were inversely related to it. Surface elevation was the most important variable in explaining soil salinity. Rice production was negatively influenced by soil salinity, thus the models predict a decrease from higher elevation zones close to the river to the shoreline. The model predicts a maximum reduction in normalized rice production index from 61.2% in 2010 to 33.8% by 2100 in the worst considered scenario (SLR=1.8m), with a decrease of profit up to 300 € per hectare. The model can be applied to other deltaic areas worldwide, and help rice farmers and stakeholders to identify the most vulnerable areas to SLR impacts.

Metabolit Cendawan Endofit Tanaman Padi sebagai Alternatif Pengendalian Cendawan Patogen Terbawa Benih Padi

Infection of seed-borne fungi on rice ( Oryza sativa ) may affect rice production and becomes an important problem in Indonesia recently. This study aimed to evaluate the potential of fungal endophyte metabolites isolated from rice ( Oryza sativa L.) to control seed-borne pathogenic fungi. Research activities involved isolation of endophytic fungi from rice, isolation of seed-borne fungi, and inhibition test of isolated endophytic fungal metabolites on seed-borne pathogenic fungi. The results showed that 3 isolates of endophytic fungi, i.e. LA6, LA11, and LA14 were potential producing antifungal metabolite. The metabolites of LA11 and LA14 isolates was able to reduce the growth of seed-borne pathogenic fungi between 18.33 and 47.28%.

Rice OVERLY TOLERANT TO SALT 1 (OTS1) SUMO protease is a positive regulator of seed germination and root development

ABSTRACTSalinity is one of the major environmental stresses affecting rice production worldwide. Improving rice salt tolerance is a critical step for sustainable food production. Posttranslational modifications of proteins greatly expand proteome diversity, increase functionality and allow quick responses to environmental stresses, all at low cost to the cell. SUMO mediated modification of substrate proteins is a highly dynamic process governed by the balance of activities of SUMO E3 ligases and deconjugating SUMO proteases. In recent years, SUMO (Small Ubiquitin like Modifier) conjugation of proteins has emerged as an influential regulator of stress signaling in the model plant Arabidopsis. However SUMOylation remain largely under studied in crop plants. We recently identified the SUMO protease gene family in rice and demonstrated a role for OsOTS1 SUMO proteases in salt stress. Interestingly, rice plants silencing OsOTS1 also show significantly reduced germination rate. Knockdown of OsOTS1 gene expression affects root growth by primarily reducing cell size rather than cell division.

Main effect QTLs associated with arsenic phyto-toxicity tolerance at seedling stage in rice (Oryza sativa L.)

Arsenic phyto-toxicity is a limiting factor affecting rice production in the Indo-Gangetic flood plain. In this study, 98 microsatellite markers were used to map quantitative trait loci (QTL) conferring arsenic phyto-toxicity tolerance (AsT) at seedling stage from a F2 population derived from a cross between an arsenic sensitive indica rice cultivar (BRRI dhan45) and an arsenic tolerant indica rice cultivar (BRRI dhan47) using selective genotyping technique. Arsenic phyto-toxicity tolerance of F2:3 population was assessed with an arsenic stress of 1.25 mg L−1 under hydroponic culture in a climate chamber. AsT indices for shoot length, root length and root-shoot biomass were estimated in terms of comparative growth in treated plants compared to that in control plants. A total of four main effect QTLs with significant LOD comprising two for relative growth in shoot length, one for each of root length and root-shoot biomass under arsenic stress were identified on chromosomes 8 and 12 using composite interval mapping approach. A large effect QTL for arsenic phyto-toxicity tolerance in root length contributing 24.9 % phenotypic variation was identified on chromosome 8 with plausible pleiotropic effect on shoot length and root-shoot biomass.

Transcriptome analysis in different rice cultivars provides novel insights into desiccation and salinity stress responses.

Drought and salinity are the major environmental factors that affect rice productivity. Comparative transcriptome analysis between tolerant and sensitive rice cultivars can provide insights into the regulatory mechanisms involved in these stress responses. In this study, the comparison of transcriptomes of a drought-tolerant [Nagina 22 (N22)] and a salinity-tolerant (Pokkali) rice cultivar with IR64 (susceptible cultivar) revealed variable transcriptional responses under control and stress conditions. A total of 801 and 507 transcripts were exclusively differentially expressed in N22 and Pokkali rice cultivars, respectively, under stress conditions. Gene ontology analysis suggested the enrichment of transcripts involved in response to abiotic stress and regulation of gene expression in stress-tolerant rice cultivars. A larger number of transcripts encoding for members of NAC and DBP transcription factor (TF) families in N22 and members of bHLH and C2H2 TF families in Pokkali exhibited differential regulation under desiccation and salinity stresses, respectively. Transcripts encoding for thioredoxin and involved in phenylpropanoid metabolism were up-regulated in N22, whereas transcripts involved in wax and terpenoid metabolism were up-regulated in Pokkali. Overall, common and cultivar-specific stress-responsive transcripts identified in this study can serve as a helpful resource to explore novel candidate genes for abiotic stress tolerance in rice.

Methane oxidation and response of Methylobacter/Methylosarcina methanotrophs in flooded rice soil amended with urea

Nitrogen, which is one of the most important factors controlling methane oxidation, affects rice production and methane emission from rice fields. Therefore, in this study, we aimed to investigate the effects of urea fertilization on methanotrophic communities and methane oxidation. Chinese rice soil was incubated with urea at concentrations of 0, 200, 400, and 800mgNkg−1 dry soil, and methanotrophic communities were analyzed by terminal-restriction fragment length polymorphism (T-RFLP) of the particulate methane monooxygenase gene (pmoA). Metabolically active methanotrophs were identified by combining T-RFLP analysis of pmoA transcripts and rRNA stable isotope probing. The results showed that a higher concentration of urea delayed the initiation of methane oxidation but stimulated the final methane oxidation rate of the rice soil. As more urea fertilizers were applied, acceleration of the methane oxidation rate occurred more rapidly. These effects were cumulative and were not directly related to the ammonium concentration in rice soil. Moreover, the activity of the Methylobacter/Methylosarcina group was stimulated by urea fertilizer, and the composition of the dominant and active methanotrophic community changed only slightly after 90h. Our results indicated that urea fertilization generally stimulated methane oxidation and methanotrophic activity, primarily by stimulating the relative abundance and activity of the Methylobacter/Methylosarcina group.

基于两种轨迹模型的褐飞虱迁飞轨迹比较研究

PDF HTML阅读 XML下载 导出引用 引用提醒 基于两种轨迹模型的褐飞虱迁飞轨迹比较研究 DOI: 10.5846/stxb201412092443 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金资助项目（41475106，41075086）；江苏省农业科技自主创新基金项目（CX（12）3056）；江苏省高校自然科学研究项目（14KJA170003）；江苏高校优势学科建设工程资助项目（IRT1147） Comparative study of migration trajectories of the brown planthopper, nilaparvata lugens (Stål), in China based on two trajectory models Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:异地预测是迁飞性害虫发生预测的重要内容，迁飞轨迹模拟和预测是能较好地反映害虫迁飞时空动态的一种异地预测方法。褐飞虱作为我国水稻生产上的一种重要迁飞性害虫，其迁飞轨迹的准确预报，可为其灾变预警和有效防控提供科学依据。为了比较选择一些准确性好、分辨率高、易于推广应用的害虫迁飞轨迹模型，选取2006年7月初发生在湖南省洪江市的一次褐飞虱重大北迁过程作为典型个例，运用中尺度天气研究和预报模式WRF，结合NCEP气象再分析数据，利用HYSPLIT和FLEXPART两种轨迹计算模式对褐飞虱迁飞轨迹进行模拟，并验证模型模拟和计算的准确度和精确度。研究结果表明：（1）WRF-HYSPLIT和WRF-FLEXPART两种轨迹计算模式在虫源地、迁飞路径（迁飞方位角和走向）、迁飞高度、迁飞速率和迁飞距离计算上总体趋势一致，但存在一定的差异，后者的起伏变化大于前者。（2）尽管两种耦合模式在调用WRF模式输出的预报场物理变量方面有很多相同之处，但WRF-FLEXPART耦合模式在运行计算过程中比WRF-HYSPLIT耦合模式多考虑了对流参数、地表胁迫和各种地形参数，因而能更全面地反映中尺度天气过程（特别是对流性天气过程）对昆虫起飞、空中飞行和降落的动力作用，也能更真实地反映地表物理过程、大气湍流结构和地形起伏对褐飞虱种群迁飞的影响。（3）从褐飞虱种群对生境和取食条件选择上看，两种模式模拟的各高度迁入种群的虫源区、迁飞路径和降落地都是合理的、准确的。但从褐飞虱迁出、空中飞行和降落所处的三维流场来看，WRF-FLEXPART模式轨迹走向与盛行气流方向的吻合度要明显高于WRF-HYSPLIT模式。（4）两种模式均可作为业务工具在迁飞性害虫测报中推广应用。 Abstract:Exotic prediction is an important content for predicting the occurrence of migratory pests. The simulations and prediction of the migration trajectory of pests is considered an ideal exotic prediction method that can reflect the spatio-temporal dynamics of the pest's migration. The brown planthopper (BPH), Nilaparvata lugens (Stål), is an important migratory pest that affects rice production in China and the accurate forecasting of its migration trajectory can provide a scientific basis for the early warnings and effective prevention of pest-related catastrophes. In order to select appropriate pest migration trajectory models with good accuracy, high resolution, and easy popularization, we screened a great northward migration event of BPH that occurred in Hongjiang City of Hunan Province at the beginning of July in 2006, as a typical case of BPH migration in China. The Weather Research and Forecast (WRF) Model, a popular mesoscale weather research and forecast model used both at home and abroad, was used to simulate and output the atmospheric background fields in high resolution combined with re-analyzed meteorological data from the National Center of Environment Predicting of the USA (NCEP). The forecasting variable fields output by the WRF model as meteorological inputs to drive the two trajectory models were coupled with the Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) Model and the Flexible Particle (FLEXPART) Dispersion Model to predict the migration trajectories and landfalling areas of BPH populations. According to the backward calculation results, the differences between some trajectory parameters of the two models, such as the pest sources, migration paths, migration heights, migrating speeds and migration distance, were compared. Finally, the observed data for the habitat, feeding conditions, and three-dimensional atmospheric airflow fields of BPH's migration were used to verify the accuracy and precision of the simulations and calculations. The results suggest several important points. First, the two models show good consistent performance on the calculations of pest sources, migration paths (migration azimuth and flight direction), migration heights, migrating speeds and migration distance. However, the variations in the migration parameters in the FLEXPART model are larger than those in the WRF-HYSPLIT model. Second, as compared to HYSPLIT, the FLEXPART model can better represent the dynamical role of meso-scale weather especially convective processes in the migration processes such as takeoff, flying duration, and landing location, and more realistically simulate land surface processes, atmospheric turbulence structure, and undulating terrain and their impact on the migration of BPH populations. This is because the FLEXPART model has included more realistic parameterization schemes for convection, surface stress, and complex terrain in the trajectory calculations, whereas the HYSPLIT model does not. Third, the two models present reasonable simulations on pest sources, migration paths, and landfalling areas in terms of the selection of BPH populations for habitats and feeding conditions. However, the trajectories simulated by the FLEXPART model showed better agreement with the prevailing winds than the HYSPLIT model's simulations. The evidence can be seen from the three-dimensional airflow fields in which the emigration, flight, and landfalling of BPH populations occurred. Fourth, both HYSPLIT and FLEXPART models demonstrated strong operational forecasting capabilities of migratory pest occurrence. 参考文献 相似文献 引证文献

Analysis of Morphological and Physiological Responses to Drought and Salinity in Four Rice (Oryza sativa L.) Varieties

Salinity and drought adversely affect rice production globally. Here we have examined physiological responses to drought and salinity across four rice cultivars with varying sensitivity to these stresses. The salt tolerant Pokkali restricts fluid entry to limit Na+ uptake under saline stress, while the drought-tolerant ARB6 needs to enhance fluid uptake under drought. Surprisingly, Pokkali does reasonably well when subjected to drought as does ARB6 under saline stress-in contrast to the stress-sensitive but high yielding varieties IR-20 and Jaya. Both tolerant varieties use long roots to mine water under deficit conditions, increasing aerenchyma and suberization of the exodermis to provide oxygen to deep-reaching roots. Major alterations in patterns of suberization in both exodermis and endodermis are undertaken, the patterns being dramatically different under the two stresses. Genes implicated in suberin biosynthesis also showed variation in transcript levels under stress, corresponding with the observed suberization patterns. Osmolyte accumulation drives uptake of water under deficit conditions, while restricting fluid flow to symplastic routes minimizes Na+ entry. Overall, the morphological and physiological responses of the tolerant varieties ensure adequate fluid flow through the transpiration stream without excessive salt uptake, thereby promoting growth under both drought and salinity.

Root QTL Pyramiding through Marker Assisted Selection for Enhanced Grain Yield Under Low Moisture Stress in Rice (Oryza sativa L)

Drought is the foremost limiting factor affecting rice production especially in the critical reproductive growth phase. Several mechanisms that resist/ tolerate or avoid drought stress have been elucidated and documented in many crops. In this study, Quantitative trait loci pyramiding (QTL) pyramiding for root morphological traits and an evaluation of the effects of QTLs in combination. Four QTLs present on chromosomes 1, 2, 7 and 9 in a nearisogenic line (NIL) population derived by backcrossing 4 doubled haploid lines of IR64/Azucena cross into IR64 were used to develop pyramids. These NILs were crossed pair-wise to arrive at combinations of two-QTL and three-QTL pyramids. Among the generated QTL pyramids, qRT6-2 x qRT11-7 and qRT6-2 x qRT19-1+7 were found to have higher yields than parent IR64 under moisture stress situation. QTLs present on different chromosomes showed maximum antagonistic effects in comparison with the different QTLs present on the same chromosome. The pyramids also show a relative increase of the NILs in terms of height, number of tillers and number of panicles, however, pyramids not show an increase in the dry matter accumulation which implies that the partitioning of the biomass is directed towards the below ground parts, leading to less sturdy plants that perform averagely under moisture stress situations.

Pengaruh Luas Lahan dan Pupuk Bersubsidi Terhadap Produksi Padi Nasional

Rice has become a staple food of Indonesia's population. The target of rice self-sufficiency continued to be a priority of the government until 2017. This study aims to analyze land use and subsidized fertilizer that affect national rice production and analysis description of the factors that affect rice production covering the spread and proportion in each of the major islands in Indonesia. The data used in this study was a secondary data derived from agricultural statistics of 2013 issued by the Data Center and Information Ministry of Agriculture. The data was processed using multiple linear regression analysis. The results that the national rice production was affected by land use, realization of subsidized urea fertilizer, realization of subsidized SP-36 fertilizer, and realization of subsidized ZA fertilizer. All of these factors on rice production was inelastic in the short term or long term. Java and Bali Island have the highest proportion in all the factors that affect national rice production.