Influence of Climate and Socio-Economic Factors on the Spatio-Temporal Variability of Soil Organic Matter： A Case Study of Central Heilongjiang Province,China

For the scientific management of farmland, it is significant to understand the spatio-temporal variability of soil organic matter and to study the influences of related factors. Using geostatistical theory, GIS spatial analysis, trend analysis and a Geographically Weighted Regression （GWR） model, this study analyzed the response of soil organic matter to climate and socio-economic factors in central Heilongjiang Province during the past 25 years. Second soil survey data of China for 1979-1985, 2005 field sampling data, climate observations and socio-economic data for 1980-2005 were analyzed. First, soil organic matter in 2005 was spatially interpolated using the Co-Kriging method along with auxiliary data sets of soil type and pH. The spatio-temporal variability was then studied by comparison with the 1980s second soil census data. Next, the temporal trends in climate and socio-economic factors over the past 25 years were investigated. Finally, we examined the variation of the response of soil organic matter to climate and socio-economic factors using the GWR model spatially and temporally. The model showed that 53.82% area of the organic matter content remained constant and 29.39% has decreased during the past 25 years. The impact of precipitation on organic matter content is mainly negative, with increasing absolute values of the regression coefficient. The absolute value of regression coefficient of annual average temperature has decreased, and more areas are now under its negative effects. In addition, the areas of positive regression coefficient of annual sunshine hours have northward shifted, with the increasing absolute value of positive coefficient and decreasing absolute value of negative coefficient. The areas of positive regression coefficient of mechanized farming as a socio-economic factor have westward shifted, with the increasing absolute value of negative coefficient and decreasing absolute value of positive coefficient. The area of regions with the positive regression coefficient of irrigatio     

Improvement of Forage Production Sustainability in the Leningrad Region under Climate Change

The increase of probability and depth of weather anomalies, which is important characteristic of climate change process, leads to higher risk of loss of perennial grasses forage yield, rise of price volatility on forage grain market. Increase of sustainability of dairy production supposes development of adapted to new weather conditions technologies of forage production, which are characterized by different investment and current costs. It generates a need of economic evaluation and comparative analysis of technologies taking into account climate change forecast and need of sustainable forage production guarantee. Purpose of the research project is the development of approaches to assessing adaptive technologies in forage production, increasing of dairy farming sustainability to changes in the external environment, including climate change. We assessed changes in forage production technologies in the Leningrad region of Russia, analyzed the implications of these changes for production and financial performance of dairy farming, proposed and tested methods for determination of the optimum harvesting time of perennial grasses. Special attention is paid to the long-term effects of changing the structure of cows＇ diet--shortening the productive use of animals, which reduces the efficiency of dairy herd use and limits the possibility of expanded reproduction. The primary method of the study is the analysis of milk production statistics in the Leningrad region and the Russian Federation. As a result of the study, the necessity to improve the production and investment planning quality, as well as the use of forecasts during planning of dairy production, is grounded.     

East Java Propolis Inhibits Cytokine Pro-inflammatory in Odontoblast-Like Cells Human Pulp

Inflammation in pulp tissue is caused by caries bacteria. Most bacteria found are Lactobacillus acidophilus. Propolis is a sticky resin material that is derived from the bees and the surrounding plants, which are reported to have several biological effects including anti-bacterial and anti-inflammatory. This study will prove the effectiveness of propolis against proinflammatory cytokines on odontoblast-like cells in human dental pulp. This study was performed on cultured odontoblast-like cells in pulp. Cell culture was derived from the pulp tissue of human M3 teeth that had been extracted. Odontoblast pulp culture was divided in three groups： group one, cultured cells with propolis; group two, cultured cells induced with inactive Lactobacillus acidophilus; group three, cultured cells induced with inactive Lactobacillus acidophilus and exposed to 3 μg/mL propolis. A measurement of TNF-α and TGF-β1 expression was done using the immunocytochemical technique to determine the effectiveness of propolis extracts from East Java Indonesia against proinfalmmatory cytokines. Data were analyzed using the analysis of variance （ANOVA） test （P = 0.05）. Propolis extract can inhibit the expression of TNF-α and increase the expression of TGF-β1 on odontoblast-like cell in human dental pulp. Anti-inflammatory effects of East Java propolis extract are associated with cytokine modulation.     

Toxicity of Bacillus thuringiensis Crystal Toxins to Field Populations of Rice Leaf Folder, Cnaphalocrocis medinalis （Guenee） and Establishment of Baseline Susceptibility to Cry1Ab

Eight insecticidal crystal proteins of Bacillus thuringiensis, CrylAa, CrylAb, CrylAc, CrylB, Cry2Aa, CrylC, CrylDa and Cry 1Ea were assessed for toxicity against 1 st instar larvae of rice leaf folder, Cnaphalocrocis medinalis （Guenee） at 48 HAT and 72 HAT. Bioassay results depicted CrylAa was the most toxic （LCso 2.35 ppm） followed by CrylBa （LCso 8,50 ppm） and CrylAb （LCso 8.73 ppm） at 48 HAT, whereas, at 72 HAT CrylAb proved to be highly toxic （LC50 0.50 ppm） followed by CrylAa （LCso 4.07 ppm）, CrylAc （LCso 4,84 ppm） and CrylBa （LCso 6.42 ppm）. Toxins Cry2Aa, CrylCa, CrylDa and CrylEa did not resulted in any mortality at 48 HAT and 72 HAT, respectively. Baseline estimates for CrylAb against 1st instar larvae of C. medinalis sampled from seven geographical locations revealed variation in LC50＇s from 0.37 ppm to LC50 16.25 ppm at 48 HAT and LC50 0.50 ppm to LC50 6.49 ppm 72 HAT, respectively with relative resistance ratios of 44-fold and 13-fold at 48 HAT and 72 HAT over the susceptible population.     

Haplll of TaSAP1-A1, a Positively Selected Haplotype in Wheat Breeding

Stress-associated protein （SAP） has functions in maintaining plant cell elongation, embryo development and response to abiotic stresses. TaSAP1-A1, one of the Triticum aestivum SAP1 （TaSAP1） members located on wheat chromosome 7A was isolated for polymorphism analysis. HaplII of TaSAP1-A1 was found significantly associated with thousand-grain weight （TGW） in multiple environments. In this study, HaplII also made a positive contribution to TGW in Population 2. The distribution of TaSAP1-A1 HapIII was tracked among varieties released in different years and geographical environments of China. The frequency of HapIII showed an increasing trend during the breeding process in two different populations. The ItapIII was gradually selected and applied from 6.36% in landraces to 13.50% in modem varieties. These results exhibited that TaSAP1-A1 HapIII was positively selected during wheat breeding, which is beneficial for grain-yield improvement. The preferred HapIIl was initially selected and applied in the higher latitude areas of China in accord with the long day season and longer grain filling stage in these areas. Moreover, the frequency of HaplII in recent modem varieties was still quite low （19.29-26.67%）. It indicated a high application potential of TaSAP1-A 1 HapIII for improving grain yield in wheat breeding.     

EalspF1, Essential Enzyme in Isoprenoid Biosynthesis from Eupatorium adenophorum,Reveals a Novel Role in Light Acclimation

Isoprenoids are a functionally and structurally diverse class of natural organic chemicals. The universal precursors of all isoprenoids, isopentenyl diphosphate and dimethylallyl diphosphate are synthesized through the mevalonate and 2C-methyl- D-erythritol 4-phosphate （MEP） pathways, respectively. Many isoprenoids produced through the MEP pathway play an important role in plant acclimation to different light environments. Eupatorium adenophorum, an invasive weed in China, presents a remarkable capacity to acclimate to various light environments, which constitutes its solid foundation of being a successful invasive species. Thus we aimed at gaining a deeper insight into the regulation of MEP pathway in E. adenophorum to further understand the invasive mechanism. 2C-Methyl-D-erythritol 2,4-cyclodiphosphate synthase （IspF or MCS） is an essential enzyme in the MEP pathway. In this paper, a novel IspF gene was cloned and characterized from E. adenophorum. Tissue-specific expression assays revealed a higher expression of EalspF1 in leaves than in stems and roots. The expression of EalspF1 was responsive to different light conditions. Some up-regulation of EalspF1 expression was also found after the treatments with signal compounds and after wounding stress. Interestingly, the over-expression of EalspF1 in Arabidopsis led to increase carotenoids contents, resulting in an enhanced tolerance to high light. Taken together, these results indicate that the EalspFl-derived enzyme participates in isoprenoid metabolism and among others, the expression of this gene in E. adenophorum is involved in the regulation of plastidial isoprenoids, which play an important role in acclimation to various light environments.     

Contribution of Drought to Potential Crop Yield Reduction in a Wheat-Maize Rotation Region in the North China Plain

With consecutive occurrences of drought disasters in China in recent years, it is important to estimate their potential impacts on regional crop production. In this study, we detect the impacts of drought on wheat and maize yield and their changes at a 0.5＆#176;＆#215;0.5＆#176; grid scale in the wheat-maize rotation planting area in the North China Plain under the A1B climate change scenario using the Decision Support System for Agrotechnology Transfer （DSSAT） model and the outputs of the regional climate modeling system-Providing Regional Climates for Impacts Studies （PRECIS）. Self-calibrating palmer drought severity index was used as drought recognition indicator. Two time slices used for the study were the baseline （1961-1990） and 40 years of 2011-2050. The results indicate that the potential planting region for double crop system of wheat-maize would expend northward. The statistic conclusions of crop simulations varied considerably between wheat and maize. In disaster-affected seasons, wheat yield would increase in the future compared with baseline yields, whereas in opposite for maize yield. Potential crop yield reductions caused by drought would be lower for wheat and higher for maize, with a similar trend found for the ratio of potential crop yield reductions for both crops. It appears that the negative impact of drought on maize was larger than that on wheat under climate change A1B scenario.     

Chromosome Mapping,Expression and Polymorphism Analysis of CRABP1 Gene in Pigs

Cellular retinoic acid-binding protein 1 （CRABP1） is a well-conserved member of cytosolic lipid-binding protein family. It is an important modulator of retinoic acid signaling. Long serial analysis of gene expression （LongSAGE） analysis suggested that CRABP1 gene was differentially expressed during prenatal skeletal muscle development in porcine. Here, we obtained the full-length coding region sequence and genomic sequence of the porcine CRABP1 gene and analyzed its genomic structures. Subsequently, we examined CRABP1 chromosome assignment using INRA-University of Minnesota 7 000 porcine radiation hybrid panel （IMpRH） and explored its tissue distribution in adult Tongcheng pigs and dynamical expression profiles in prenatal skeletal muscle （33, 65 and 90 days post coitus, dpc） from Landrace （lean-type） （described as L33, L65 and L90） and Tongcheng pigs （obese-type） （described as T33, T65 and T90）. The CRABPI gene was mapped to chromosome 7ql 1-q23 and closely linked to the microsatellite marker SWR1928. Quantitative real-time PCR showed that CRABP1 mRNA was highly expressed in lung and stomach, moderately expressed in placenta and uterus, and weakly expressed in other tissues. Moreover, CRABP1 gene was down-regulated during prenatal skeletal muscle development in both Landrace and Tongcheng pigs and it was expressed much higher in T33 than L33. Two single-nucleotide polymorphisms （SNPs） were detected by sequencing and mass spectrometry methods, allele frequency analysis indicated that g. 281 （G〉A） and g. 2992 （G〉A）were deviated from Hardy-Weinberg equilibrium in the Landrace and DLY （Duroc×（Landrace×Yorkshire）） pig breeds.     

Contribution of Adventitious Roots to Water Use Strategy of Juniperus sabina in a Semiarid Area of China

duniperus sabina Linnaeus, an evergreen shrub with prostrate life form, can effectively prevent sand moving and is an important tree species for reforestation in semiarid areas of China. It has laterally distributed adventitious roots and a deeply distributed main root system. To detect water movement between the main root system and adventitious roots, we adopted heat pulse sensors using the Heat Ratio Method, a high precision method for measuring low sap flow rates. Two sensors were implanted in each individual in the stem between the main root system and adventitious roots, and another two in lateral stems distal to all the roots. Positive sap flows during nighttime, even under saturated air moisture conditions, were detected only between the main root system and adventitious roots under drought conditions, and the rate of flow increased as drought progressed and decreased or disappeared after rain events. The results demonstrated the existence of water movement from the main root system to adventitious roots, and combined with the high contribution of nighttime sap flow to transpiration （11%-16%） the results indicate that it also involves the process of hydraulic lift, a water movement from moist subsoil to dry surface soils. Integrated water use strategy between the main root system and adventitious roots via the process of hydraulic lift of soil water maximizes water acquisition efficiency from both subsoil water and water from rain pulses on the soil surface; this increases survivability in the water-limited environment of semiarid areas.     

Molecular Characterization and SYBR Green I-Based Quantitative PCR for Duck Hepatitis Virus Type 1

To determine the genomic sequence of a duck hepatitis virus type 1 （DHV-1） strain, real-time quantitative polymerase chain reaction （RTQ-PCR） assay based on SYBR Green I technology was developed to target 3D gene of DHV-1, Comparative sequence analysis showed that the genome has a typical picornarivus genetic organization, and strain DHV-1 R genetic organaiztion is 5＇ untranslated region （UTR）-VP0-VP3-VPI-2A1-2A2-2B-2C-3A-3B-3C-3D-3＇ UTR, DHV-1 R has close relationship with Parechovirus, and has 95.1-99.1% nucleotide sequence identity with other DHV-1 strains. Based on the DHV-1 sequences in GenBank, three pairs of specific primers were designed to amplify DHV-1 using real-time PCR. The results showed that real-time PCR Tm value is 85.6℃ and the real-time PCR provides a broad dynamic range, detecting from 102 to 109 copies of DHV-1 cDNA per reaction. No cross-reactions were found in specimens containing DPV, AIV and NDV. It is concluded that DHV-1 belongs to a new group of the family Picornaviridae that may form a separate genus most closely related to the genus Parechovirus. All results showed that the real-time PCR has high sensitivity and specificity to detect DHV-1 using SYBR Green I dissociation curve analysis, isolates can be distinguished by their melting temperature. These methods are rapid, sensitive, and reliable, and can be readily adapted for detection of DHV-1 from other clinical samples.     

Photosynthetic Characteristics and Antioxidative Metabolism of Flag Leaves in Responses to Nitrogen Application During Grain Filling of Field-Grown Wheat

A two-factorial experiment was conducted with two wheat cultivars, SN1391 （large spike and large grain） and GC8901 （multiple spike and medium grain）, and two nitrogen （N） application rates （12 and 24 g N m^-2）, to investigate the responses of photosynthetic characteristics and antioxidative metabolism to nitrogen rates in flag leaves of field-grown wheat during grain filling. The results showed that the content of N and chlorophyll （Chl） in wheat flag leaves decreased after anthesis and the net photosynthetic rate （Pn）, effective quantum yield of PS Ⅱ （Фps n）, efficiency of excitation capture by open PS Ⅱ reaction centers （Fv′/Fm′）, and photochemical quenching coefficient （qp） began to decrease at 14 days after anthesis. However, the maximal efficiency of PS Ⅱ photochemistry （Fv/Fm） decreased slightly until the late period of senescence and the nonphotochemical quenching coefficient （NPQ） increased during flag leaves＇ senescence, As a result, a conflict came into being between absorption and utilization to light energy in flag leaves during senescence, which might accelerate the senescence of flag leaves. Compared with GC8901, the lower plant population of SN1391 during grain filling was helpful to maintain the higher content of photosynthetic pigment, activity of PS II, and Pn in flag leaves during senescence, The delayed decrease in antioxidative enzyme activity and the lower degree of membrane lipid peroxidation in the senescing leaves of SN1391 were beneficial to protect the photosynthetic apparatus, which lead to the prolonged duration of CO2 assimilation. With the increase of N application, the Chl content of SN1391 flag leaves and the efficiency of excitation captured by open PS Ⅱ centers increased. At the same time, the thermal dissipation in SN1391 flag leaves at high N （HN） treatment decreased and Фps Ⅱ improved greatly, which were favorable to the increase of Pn. The SOD, POD, CAT and APX activities in the flag leaves of SN1391 increased     

Evaluation of the Pathogenicity and Immune Response of Nervous Necrosis Virus Isolated in Vietnam

Eight strains of nervous necrosis virus （NNV） isolated in Vietnam were used to detect the pathogenicity and immune response in sea bass （SB）. All strains induced cytopathic effect in SB cell line, complete destruction of monolayer of cells appeared after seven days post infection （dpi）. Virus titer was different for each strain, TCIDso ranged from 102.7 to 1069, and LDs0 from 1015 to 1075. Five NNV strains named QN 02, QN 05, QN 07, ND 11 and KH 05 had higher virulence than the other three, the first causing 100% mortality in experimental fish 3-5 dpi. NNV KH 05 had the highest antigenic similarity, and it was inactivated completely by 0.2% formalin, 0.002 mol/L binary ethylenimine （BEI） and 0.1% beta-propiolactone. The neutralization antibody titer obtained in fish of groups immunized by BEI 0.002 M and beta-propiolactone 0.1% inactivated virus was four to eight times higher than that of the group treated with the formalin inactivated virus. The antibody titer in fish immunized with beta-propiolactone inactivated virus was more persistent. The efficacy of vaccines developed from beta-propiolactone inactivated virus and aluminium hydroxide （AH） or aluminum phosphate （AP） was observed by intramuscularly immunizing Epinephelusfuscoguttatus size 1.5 cm. Neutralizing antibodies appeared in vaccinated fish on 10th day post-immunization （dpi） at a dilution of 1：16; 1：32 and highest levels were reached on 30-45 dpi, at dilutions of 1：256 and 1：512, after treatment with AH and AP vaccine, respectively. The relative percent of survival （RPS） of vaccine at 30 dpi was highest with challenge doses 0.2-1 × 10^6.8 TCIDs0, the RPS varied from 80%-83.3% in both groups of AH and AP immunization. This result provides the basis for developing a vaccine against NNA disease.     

Effect of Biogas Digested Liquid on OH4 and N2O Flux in Paddy Ecosystem

Biogas production generates digested slurry as a byproduct. It can be used as a fertilizer especially after its conversion into digested liquid. A pot based study was conducted in order to evaluate the effect of the application of digested liquid on CH4 and N2O flux, and plant biomass in paddy. Analysis revealed that digested liquid treated soils released more CH4 compared to ammonium sulphate and the control. Ammonium sulphate treated soil emitted the highest N20 whereas digested liquid application decreased its emission significantly. Further, the cumulative emission over 101 d of the experiment was found to be higher for CHa （16.9 to 29.9 g m^-2） compared to N20 （-49.3 to 18.9 mg m^-2） for all treatments. Digested liquid application had positive impact on plant variables such as panicle number and weight of panicles. This study suggests that digested liquid application significantly decrease N20 emission and increase CH4 emission possibly due to affecting the availability of organic C in the soil to microbial activity for methanogenesis. Another possibility for enhancing CH4 emission by following biogas digested liquid could be attributed to the increase in plant biomass.     

Quantitative Analysis of Influence Force of Shanghai Expo on GGDP

Quantitative study of the impact of Shanghai World Expo on green GDP （GGDP） is significant for deploying sustainable development policy in China. The formula of GGDP is： GGDP = GDP--the loss of natural resources environment relegation cost ＋ comprehensive utilized value of waste. Based on this, the study employed vector autoregressive （VAR） model to predict the value of GGDP and other economic variables on condition that there was no Shanghai World Expo. Then Influence of Expo is defined as the rate of increase of GGDP. The result demonstrated that Shanghai World Expo had accelerated the growth rate of GGDP vastly with the elimination of effect of Beijing Olympics. Additionally, the quantitative analysis between GGDP and other economic variables suggested GGDP would replace GDP to evaluate the development of economy. Finally, the paper proposed that incidents like World Expo can enhance the level of influence for a country and that post-impact of Shanghai Expo should continue to be used to promote GGDP and that GGDP should serve as one of the indicators in assessment of political achievement.     

Resistance of Hard Tick （Ixodidae） with some Acaricide in Cattle （Naturally Infestation） in Sulaimani Governorate Fields-Kurdistan Regional/Iraq

A study carried out for assessment of acaricide for control and how to show resistance of hard tick （Ixodidae） with some types of acaricide which available in Sulaimani marked froro February to April 2012, isolated 80 cattle （local breed） naturally infested with hard tick. Six hundred and fifteen ticks min7 tick/cattle including three genera species were collected and identified, the highest Boophilus spp. followed by Hyalomma spp., and Rhipicephalus spp. were less frequent species collected. Experimental cattle divided into four groups each group content 20 cattle, treatment with four types acaricide and their average of infestation in cattle with Boophilus spp. 33 （41.25%） as the commonest, followed by Hyalomma spp. 31 （75.38%）, Rhipicephalus spp. 11 （13.75%） and 5 （6.25%） found mixed infested with Boophilus spp. and Hyalomma spp. 65 （81.3%） of cattle samples had emaciation and skin lesions. According to site of infestation, it showed that inguinal region was the most common predilection site for the ticks. Observed the genera Boophilus spp., there were highly significant differences （12.52%） between different tick species when calculated by general test （LSD）. The objective of this study was to estimate and compare these acaricide to control hard tick, and there was highly significant relation between different species of hard ticks when treated by these acaricide, according to the chi-square tests. The activities of the acaricide through the time of application were different on the tick genera species. Diazinon （60%） and carbamate （saven 85%） has been a greater degree than other acaricide resistance, while shows the activity of both acaricide injectable ivermactin and cypromethrein through the early time on all species. The results of the study otherwise provide encouraging possibilities for the potential use recommended dose with both acaricide ivermactin-l% and cypromethrine-10%.     

Characterization and Chemometrics Based-Approach to Classify Some Algerian Blossom Honeys

Physicochemical characterization of 82 Algerian honeys, collected between 2005 and 2010, from different botanical and geographical origins were analyzed. The studied parameters were： water content, pH, free acidity （FA）, electrical conductivity （EC）, ash content, hydroxymethylfurfuraldehyde （HMF）, proline content, specific rotatory power and color. Most of the measured parameters had showed values in the range of the international standards, with a particular richness in proline and ash content. Chemometrics-based approach reveals that the discriminated groups were Citrus, Ziziphus and forest even with over represented groups like Eucalyptus. Principle component analysis （PCA） enabled to extract three principal components explaining nearly 65% of total variance, PCj and PC2 were related to botanical origin whereas PC3 to honey age. Analysis of variance showed that the studied variables were almost different depending on botanical, geographical origin and season. The current study also shows the presence of diverse honey varieties in Algeria. The collected data will contribute to the creation of products with protected geographical or/and botanical origins.     

Interactive Effects of Elevated CO2 and Temperature on Rice Planthopper,Nilaparvata lugens

It is predicted that the current atmospheric CO2 concentration will be doubled and global mean temperature will increase by 1.5-6＆#176;C by the end of this century. Although a number of studies have addressed the separate effects of CO2 and temperature on plant-insect interactions, few have concerned with their combined impacts. In the current study, a factorial experiment was carried out to examine the effect of a doubling CO2 concentration and a 3℃ temperature increase on a complete generation of the brown planthopper （Nilaparvata lugens） on rice （Oryza sativa）. Both elevated CO2 and temperature increased rice stem height and biomass of stem parts. Leaf chlorophyll content increased under elevated CO2, but only in ambient temperature treatment. Water content of stem parts was reduced under elevated temperature, but only when coupled with elevated CO2. Elevated CO2 alone increased biomass of root and elevated temperature alone enhanced leaf area and reduced ratio of root to stem parts. Brown planthopper （BPH） nymphal development was accelerated, and weight of and honeydew excretion by the F1 adults was reduced under elevated temperature only. Longevity of brachypterous females was affected by a signiifcant interaction between CO2 and temperature. At elevated temperature, CO2 had no effect on female longevity, but at ambient temperature, the females lived shorter under elevated CO2. Female fecundity was higher at elevated than at ambient temperature and higher at elevated CO2 than at ambient CO2. These results indicate that the combined effects of elevated temperature and CO2 may enhance the brown planthopper population size.     

Responses of Lowland NERICA and Improved Oryza sativa Rice to Phosphorus and Nitrogen in Sudan Savanna Agroecosystem

The responses of five inter-specific lowland rice cultivars （NERICA-L-19, NERICA-L-20, NERICA-L-41, NERICA-L-42, and NERICA-L-60） and four improved Oryza sativa cultivars （FKR 19, BW 348-1, WITA 4, and SIPI 6923033） to levels of phosphorus and nitrogen fertilization were compared on a Typic Natrustalfat Kadawa in the Nigerian Sudan Savanna in 2006 and 2007 The responses of the NERICA-L eultivars to N and P fertilization were similar to the O. sativa cultivars. In a dry year （2007）, the NERICA-L cultivars gave higher yields than O. sativa cultivars. Phosphorus level did not significantly affect crop physiology, yield, and yield components of all the cultivars. Pooled across cultivars, N and P levels, days to panicle initiation, mid-flowering and maturity were, respectively delayed by 17.0, 15.6 and 6.4 days in 2007 compared to 2006. NERICA-L-42 and NERICA-L-41 were the most stable, exhibiting the least difference in duration to maturity between the two years （3.5 and 4.4 days, respectively）, and could therefore be more adapted to rain-fed environments prone to frequent droughts. Increasing N levels from 0 to 120 kg hal produced yield increments of 62.9 and 37.2% in 2006 and 2007, respectively. Cultivars FKR 19 and WITA 4 gave higher yields in 2006 （3940 and 3542 kg ha^-1, respectively）, while in 2007, NERICA-L-42, NERICA-L^-19 and NERICA-L-20 ranked among the highest in grain yield （3935, 3807 and 3726 kg hal, respectively） and could be recommended to resource-poor farmers. a