Influence of Climate Conditions on Potato Yield and Studies on the Forecasting Model of Potato Yield

[Objective]The aim was to research influence of climate conditions on potato yield and establish the forecasting model of potato yield.[Method]SPSS（Statistical Package for the Social Sciences） was used to separate potato output into meteorological yield and tendency yield over the years,and analysis of the relation between potato climate yield and meteorological factors was carried out.[Result]The result showed that affecting yield factor consisted of the universality and regional.The universality included vapour pressure or relative humidity of air in last August-September,precipitation in late June to early July and in mid-August;The regional is including precipitation in January and in early to mid April,vapour pressure of air in May.Prediction model about yield was established by using stepwise regression method,which qualified rates of fitting better quality.[Conclusion]Because of its long effective period,high accuracy and simplicity to dalculate,the method provided a guarantee for weather service on the crop farming of potatoes.

Effect of Nitrogen on Yield and Oil Quality of Sunflower (<i>Helianthus Annuus</i>L.) Hybrids under Sub Humid Conditions of Pakistan

Sunflower (Helianthus annuus L.) has emerged as an economically important crop in Pakistan due to its significant share in vegetable oil production. The plant metabolic processes require protein to increase the vegetative, reproductive growth and yield of the crop. The protein is wholly dependent upon the amount of nitrogen fertilization available for plant use. A two-year field study was conducted in 2008 and 2009. The objective was to determine the effect of different nitrogen (N) levels (N1 = 0 kg·ha–1, N2 = 60 kg·ha–1, N3 = 120 kg·ha–1, N4 = 180 kg·ha–1 and N5 = 240 kg·ha–1) on three sunflower hybrids (Hysun-33, Hysun-38 and Poineer-64A93) in agro-climatic conditions of Gujranwala, a sub-humid region in the centre of the Punjab province of Pakistan. A randomized complete block design split plot experiment was set-up with cultivars in the main plots and N levels in the subplots. Results showed that Hysun-38 gave maximum TDM (15815 kg·ha–1) and maximum grain yield (3389 kg·ha–1), while minimum TDM (14640 kg·ha–1) and grain yield (3125 kg·ha–1) was observed in Hysun-33. Among different N rates evaluated, N4 gave maximum TDM (17890 kg·ha–1) and grain yield (3809 kg·ha–1) compared to the other N rates. The maximum oil content (46.2%) was observed in Hysun-38 without application of N fertilizer (N1), while the minimum oil content (40.6%) was observed from N5 treatment. In conclusion, the application of 180 kg·ha–1 N to Hysun-38 provided the best combination for good yield in sunflower crop under the prevailing sub-humid conditions of Pakistan.

Yield strength prediction of rolled Al-(1.44-12.40)Si-0.7Mg alloy sheets under T4 condition

The effects of Si content on the microstructure and yield strength of Al-(1.44-12.40)Si-0.7 Mg(wt.%)alloy sheets under the T4 condition were systematically studied via laser scanning confocal microscopy(LSCM),DSC,TEM and tensile tests.The results show that the recrystallization grain of the alloy sheets becomes more refined with an increase in Si content.When the Si content increases from 1.44 to 12.4 wt.%,the grain size of the alloy sheets decreases from approximately 47 to 10μm.Further,with an increase in Si content,the volume fraction of the GP zones in the matrix increases slightly.Based on the existing model,a yield strength model for alloy sheets was proposed.The predicted results are in good agreement with the actual experimental results and reveal the strengthening mechanisms of the Al-(1.44-12.40)Si-0.7 Mg alloy sheets under the T4 condition and how they are influenced by the Si content.

Phenotypic plasticity and genetic variation of cotton yield and its related traits under water-limited conditions

Global warming is limiting availability of water resources in arid and semi-arid regions,and so understanding water use efficiency(WUE)is increasingly important for agricultural production in those areas.As China is the largest cotton producing area,the problem of balancing WUE and efficient cotton production is a major issue.In this study,we used a natural population of 517 Upland cotton accessions to conduct a water-controlled trial in south and north of Xinjiang over two years.A total of 18 traits including agronomic traits,fiber yield indices and fiber quality indices,were investigated for broad-sense heritability and coefficient of variation.Appropriate water limitation was found to promote the establishment of favorable agronomic traits in cotton,associated with an increased cotton yield of 8.46%in Xinjiang,at the expense of a certain degree of fiber quality,such as decreased fiber length and an over-higher micronaire value.We detected 33 QTL related to response to water limitation using a drought resistance coefficient(DRC),and 6 QTL were found using a comprehensive indicator of CIDT(comprehensive index of drought tolerance)at the genetic level by integrating resequencing data.Two novel QTL-hotspots including six differentially expressed genes(DEGs)were further identified related to the drought response of cotton.These findings not only suggested a new approach to irrigation of cotton fields in Xinjiang,but also provided abundant genetic evidence for genetic breeders to study drought improvement of crops.

Understanding yields in alley cropping maize (Zea mays L.) and Cassia siamea Lam. under semi-arid conditions in Machakos, Eastern Kenya

Six seasons of experiments in Machakos, Kenya, revealed that above about 150 mm of rainfall, maize yields per row in alley cropped “replacement” agroforestry (AF) plots, of Cassia siamea Lam. and maize ( Zea mays, cv. Katumani Composite B), may be expected to exceed those in the control (sole maize) plots. Such yields were insufficient to compensate for the area “lost” to the hedgerows. Below about 150 mm the control plots may be expected to perform better. This result was due to competition for water. Greater association of the fine roots of Cassia and maize was observed in the middle of the alleys than near the hedgerows. Photosynthetic consequences of shading were insignificant relative to other factors. In the alleys, reductions of soil temperature due to shade in the western and eastern maize rows were higher than in the middle row. Soil moisture extraction was higher in the AF than in the control plots. In the AF plots, moisture extraction was greater under the central maize rows than under those nearest the Cassia. Yield patterns followed such soil temperature and soil moisture patterns. Maize transpiration and photosynthetic rates were significantly higher in the control than in the AF plots during a below average rainy season but not during above average rainy seasons. It is concluded that alley cropping under semi arid conditions should be approached differently from the system worked on. It must at least provide strong physical protection of crops and/or soils and have a strong economic incentive to be of interest to the farmers.

Crop Yield Estimation with Farmers＇ Appraisal on Weather Condition

Crop yield is mainly affected by weather condition, inputs, and agriculture policies. In the crop yield estimation, farmers＇ perception on weather conditions lead to the assessment of how well yield would be compared to the previous seasons. This paper applies Bayesian estimation method to estimate crop yield with farmers＇ appraisal on weather condition. The paper shows that crop yield estimation with farmers＇ appraisal on weather condition takes into account risk proportionally to climate change. In light of the United Nations efforts aimed to build a consolidated agriculture statistical system across countries, the statistical model developed here should provide an important tool both for the crop yield estimation and food price analysis.

Effects of Subsoiling on Some Soil Physical Properties and Wheat Yield in a Dry Land Ecological Condition

In order to evaluate the effect of subsoiling on the soil physical properties and wheat yield in dry land conditions, this research was conducted in Mamassani area of Fars province in Iran. The experiment was laid down in the form of a complete block experimental design with four treatments and four replications for three years. Treatments included： （1） conventional tillage without using subsoiler which was control treatment （So）; （2） using subsoiler with the shank space of 40 cm which was equal to the subsoiling depth （SO; （3） using subsoiler with the shank space of 60 cm which was 1.5 times of the subsoiling depth （S2）; and （4） using subsoiler with the shank space of 80 cm which was 2 times of the subsoiling depth （S3）. Subsoiling depth was set at 40 cm which was the lower limit of the hard pan depth in the soil. Soil cone index, soil bulk density, soil moisture content, wheat yield, and yield components were measured in this study and SAS software was used to analyze the collected data. Results showed that subsoiling decreased the soil bulk density and cone index, and increased water retention of the soil. Results also revealed that applying subsoiler increased wheat yield and yield components in our dry land conditions. Since subsoiling improved soil physical conditions and increases wheat yield, applying subsoiler in such a dry land conditions is therefore recommended. Results of this study also showed that subsoiling with the shank space of 40 cm and 60 cm had better performance compared to the shank space of 80 cm. On the other hand, shank space of 40 cm reduced the subsoiler effective working width and consequently effective field capacity. Therefore, subsoiler with a shank space of 60 cm is recommended for application in dry land soils of our type.

Effects of Meteorological Conditions on Yield and Quality of Facility Hami Melon

With different varieties of facility Hami melon(Cucumis melo var. sacchairinus) as test materials, the effects of meteorological conditions on the yield and quality of different varieties of facility Hami melon were analyzed. The results showed that among the yield and quality traits of melon, the variation degree of average single melon weight was the highest, and the coefficient of variation was 33.05%. The variation degree of leaf area index was the lowest, and the coefficient of variation was 11.00%. Through the correlation analysis of meteorological factors with the yield and quality of facility Hami melon, it was found that the quality traits of facility Hami melon were significantly positively correlated with maximum temperature and sunshine duration, and significantly negatively correlated with precipitation. The yield traits were positively correlated with maximum temperature, sunshine duration and precipitation.

Study on the Yield Reduction Mechanism of Soybean Planted under Continuous and every Second Year Cropping Conditions

Three-year investigation was conducted to demonstrate the mechanism of reduction of soybean yield aroused by continuous and every second year cropping. Compared to normal cropping, there are many unfavorable changes in some major elements of soybean plant and soil environment. Chloropyll content was lower. Phosphorous content of soybean plant was decreased seriously. Potassium content was lower while calcium content was higher. Magnesium content was wot affected and decreased in susceptive varieties. Some deseases and insects of soybean under continuous and wery second year cropping conditions became serious as continuous years prolonged. Organic matter content tended to go down from normal rotation to continuous cropping. Amount of bacteria and antinomyces decreased while amount of fungi increased. The development of symbiotic nitrogen fixation system wsa deteriorated.

Conditional genes for grain yield in rice

Grain yield in cereal crops was an eternal theme.The number of panicles perplant(PN),filled spikelets per panicle(FSP),and 1000-grain weight(TGW)were the three important yield components.Some QTLs for rice yield had beenmapped,but conditional QTLs for grain yield had not been analyzed.Phenotypicvalues of yield traits,which had no influence on the given components,wereused for QTLs conditional analysis.This study was to uncover conditional QTLsfor rice yield in a RIL population,and to search for evidences on the geneticbasis of yield QTLs.

Influence of heat treatment conditions on bending characteristics of 6063 aluminum alloy sheets

Bending deformation behaviors of solution treated(ST),natural aged(NA)and T6tempered6063aluminum alloy sheetswere studied by three-point bending tests.The changes of bending force,interior angle,bending radius and sheet thickness in thefillet region were analyzed by experimental measurements and numerical simulations.The results showed that the bendingcharacteristics were strongly dependent on the heat treatment conditions.The T6alloy sheets were bent more sharply and localplastic deformation occurred severely in the fillet region.However,the ST and NA alloy sheets exhibited relatively uniform bendingdeformation and large bending radius.The bending force of T6alloy was the highest,followed by the NA alloy and that of the STalloy was minimum.After unloading,as compared with the ST and NA alloys,the springback of T6alloys was markedly larger.Theaging time showed a positive sensitivity on the springback and non-uniform bending deformability.The bending characteristics areattributed to the combined effects of yield strength,yield ratio and coefficient of neutral layer.

Innovation of the double-maize cropping system based on cultivar growing degree days for adapting to changing weather conditions in the North China Plain

Double-maize cropping system is an effective option for coping with climate change in the North China Plain. However, the effects of changes in climate on the growth and yield of maize in the two seasons are poorly understood. Forty-six cultivars of maize with different requirements for growing degree days (GDD), categorized as high (H), medium (M) or low (L), and three cultivar combinations for two seasons as LH (using JD27 and DMY1 from category L in the first season;and YD629 and XD22 from category H in the second season), MM (using JX1 and LC3 from category M in the first season;and ZD958 and JX1 from category M in the second season) and HL (using CD30 and QY9 from category H in the first season;and XK10 and DMY3 from category L in the second season) were tested to examine the eco-physiological determinants of maize yield from 2015 to 2017. The correlations between the combinations of cultivars and grain yield were examined. The combination LH produced the highest annual grain yield and total biomass, regardless of the year. It was followed, in decreasing order, by MM and HL. Higher grain yield and biomass in LH were mainly due to the greater grain yield and biomass in the second season, which were influenced mainly by the lengths of the pre- and post-silking periods and the rate of plant growth (PGR). Temperature was the primary factor that influenced dry matter accumulation. In the first season, low temperatures during pre-silking decreased both the duration and PGR in LH, whereas high temperatures during post-silking decreased the PGR in MM and HL, resulting in no significant differences in biomass being observed among the three combinations. In the second season, high temperatures decreased both the PGR and pre- and post-silking duration in MM and HL, and consequently, the biomass of those two combinations were lower than that in LH. Moreover, because of lower GDD and radiation in the first season and higher grain yield in the second season, production efficiency of temperature and radiation (Ra) was the highest in LH. More importantly, differences in temperature and radiation in the two seasons significantly affected the rate and duration of growth in maize, and thereby affecting both dry matter and grain yield. Our study indicated that the combination of LH is the best for optimizing the double-maize system under changing climatic conditions in the North China Plain.

Forecasting Methods of Agrometeorological Conditions in the Northern Zone of the Republic of Kazakhstan

This work presents the forecast of quality indicators of wheat from weather conditions in the Northern zone of the Republic of Kazakhstan, obtained on the basis of the correlation of protein and gluten content of grain with an average monthly air temperature and precipitation. The equation obtained by the authors allows estimating the quality of grain with the monthly advance, which is important in the organization of harvesting of grain crops.

Extraction Conditions of Essential Oil from Eucalyptus Leaves by Distillation

[Objectives]To explore the extraction conditions of essential oil from eucalyptus leaves.[Methods]The essential oil of eucalyptus leaves was extracted by steam distillation,and the yields of essential oil from eucalyptus leaves under different extraction times,soaking times and different solid-liquid ratios were analyzed through orthogonal test with three factors and three variables.[Results]The effects of various factors on extraction results were:distillation time>solid-liquid ratio>soaking time.When the extraction time and soaking time were 1.5 and 2 h,and the solid-liquid ratio of eucalyptus leaves to distilled water was 1:10,the yield of essential oil was the highest(0.8%).The yield of essential oil increased with the increase of extraction and soaking time,but when reaching the optimal value,the yield decreased with the extension of time.Increasing the solid-liquid ratio can improve the yield of essential oil,but beyond a certain value the yield increased gradually while the cost performance decreased.[Conclusions]The results will provide some reference for the recovery and utilization of eucalyptus leaves.

Investigation on Yield Behavior of 7075‑T6 Aluminum Alloy at Elevated Temperatures

Aluminum alloys have drawn considerable attention in the area of automotive lightweight.High strength aluminum alloys are usually deformed at elevated temperatures due to their poor formability at room temperature.In this work,the yield behavior of 7075 aluminum alloy in T6 temper(AA7075-T6)within the temperature ranging from 25°C to 230°C was investigated.Uniaxial and biaxial tensile tests with the aid of induction heating system were performed to determine the stress vs.strain curves and the yield loci of AA7075-T6 at elevated temperatures,respectively.Von Mises,Hill48 and Yld2000-2d yield criteria were applied to predicting yield loci which were compared with experimentally measured yield loci of the AA7075-T6.Results show that yield stress corresponding to the same equivalent plastic strain decreases with increasing temperature within the investigated temperature range and the shape of yield loci evolves nearly negligibly.The experimental yield locus expands with an increase of equivalent plastic strain at the same temperature and the work hardening rate of AA7075-T6 exhibits obvious stress-state-dependency.The nonquadratic Yld2000-2d yield criterion describes the yield surfaces of AA7075-T6 more accurately than the quadratic von Mises and Hill48 yield criteria,and an exponent of 14 in the Yld2000-2d yield function gives the optimal predictions for the AA7075-T6 at all investigated temperatures.

Genetic Dissection of Net Effects Between Yield and Its Components in Sea Island Cotton (Gossypium barbadense L.)

The number of bolls, individual boll weight, and lint percentage are three important yield components of lint yield of cotton. In the present study, nine parents, twenty F1, and twenty F2 crosses of intraspecific hybrids of sea island cotton （Gossypium barbadense L.） were grown at Tarim University, Alar, Xinjiang, China, in 2000 and 2001. Lint yield and its three component traits were measured and analyzed by an extended conditional mixed linear model approach. Lint percentage made the largest contribution to additive, additive x environment, and dominance x environment variations for lint yield. The contribution ratios of number of bolls, individual boll weight, and combined contribution of these two traits to additive x environment and dominance x environment variations for lint yield were not statistically significant. Lint yield of different parents could be affected differently by lint percentage. Lint yield of some parents was closely correlated with lint percentage, whereas for other parents, the behavior of individual boll weight and number of bolls played much more important roles on lint yield than that of lint percentage. It was shown by the conditional and conventional predicted additive x environment interaction effects of parents that the environment condition could influence different parents with varied effects.

A PRELIMINARY STUDY ON THE VARIATION FEATURES OF GRAIN YIELD OF CHINA IN RECENT 40 YEARS

Based on grain yield data of China, the vanation features of grain yield in China in recent 40 years and their relationships with the associated factors were analyzed. Results show that the total grain yield increased gradually, and its interannual variation is influenced principally by unit area crop yield (about 70 percent in average). The influences of agricultural technology, social factors and weather conditions on thet area crop yield can be separated because of their unique variation trends and time scales. The influence of agricultural technology is in a smoothly and gradually incremental trend, and the influence of the social factors is oscillated with three waves in recent 40 years, and the influence of weather conditions is fiuctuated sharply from year to year. Their mean effects on the inter-annual variation of unit area crop yield are about 35 to 40 percent, 10 to 15 percent and 50 percent respectively. In the view point of predictions, the effects of weather conditions are much more important.

Factors Impacting Corn (<i>Zea mays</i>L.) Establishment and the Role of Uniform Establishment on Yield

Information from actual farm fields can help corn producers understand the value and importance of establishing uniform crop emergence and within-row plant spacing. Thirty-eight fields planted with corn (Zea mays L.) by North Dakota producers were evaluated to determine the effects of uneven plant emergence timing and within-row plant space variability, as well as identifying contributing factors. Rows within a planter’s width with the most variability yielded 6% less than the least variable rows. Individual ear weights decreased as the number of days after normal emergence (date when 50% of plant stand emerged) increased. Ears next to within-row gaps (>30.5 cm) weighed 11% more than the normally spaced plants. Combined ears from both plants situated <5.1 cm apart weighed 36% more than from a single ear from normally spaced plants. Surface residue and planting speed impacted stand establishment variability more often than other factors measured. Producers should assess each field environment individually in order to identify best practices to achieve uniform stand establishment.

Evaluation of Six Modern Varieties of Potatoes for Yield, Plant Growth Parameters and Resistance to Insects and Diseases

Six modern varieties of potatoes (Diamant, Cardinal, Granola, Felsina, Provento and Asterix) were investigated for their growth parameters and yield to determine their suitability for production in Bangladesh. Results indicate significant variations among the varieties in the yield and morphological characteristics and no difference in the number of main stems per hill. Among the six studied varieties, Asterix produced the greatest yield (29.60 t/ha), the greatest number of tubers per hill (13 tubers/hill), the largest percentage (84%) of medium sized tubers (28 - 55 mm diameter), and the greatest plant height (61.33 cm). Diamant performed second after Asterix with a yield of 28.33 t/ha, and a plant height of 59.0 cm. Felsina produced the lowest yield (25.13 t/ha) and the lowest number of tubers per hill (8.67 tubers/hill). In a farmers’ perception study, where farmers scored the yield and resistance to diseases and insect damage of the six varieties, from 1 to 6 (6 being the highest and 1 being the lowest), Asterix was the most preferred variety by farmers with scores of 6, 5.67 and 5.83 for yield, disease resistance and insect resistance respectively. Provento was the least preferred by farmers with a score of overall performance of 4. The results of this study indicate that Asterix and Diamant have the potential to be grown successfully by the farmers in Bangladesh.

Yields and Nitrogen Use Efficiencies of Rice (Oryza sativa) at Different Sites Using Different Nitrogen Fertilizer Application Rates and Controlled-release Urea to Conventional Urea Ratios

Rice yields and nitrogen use efficiencies were studied at five sites in southwest China using two nitrogen fertilization rates and five controlled-release urea（ CRU） to ordinary urea（ U） ratios. The fertilizer treatments significantly increased rice yields compared with the control（ no nitrogen added） yields to different degrees at different sites. Applying CRU and U increased the rice yield more than adding the same amount of nitrogen as U only. Higher increasing production rate were found using a nitrogen application rate of 105 kg/hm2 than 150 kg/hm2. A 70∶ 30 CRU∶ U ratio increased the yield more than other four ratios. Nitrogen use efficiency was 21. 9% higher using a nitrogen application rate of 105 kg/hm^2 than 150 kg/hm^2,and 46. 6%,38. 1%,34. 7%,and 22. 2% higher than when only U was applied when CRU∶ U ratios of 70 ∶ 30,50 ∶ 50,100 ∶ 0,and 30 ∶ 70,respectively,were used. A 70 ∶ 30 CRU ∶ U ratio gave the highest economic output（ yuan/hm^2）. Applying both CRU and U gave an output 3 078. 87 yuan/hm^2 higher at a nitrogen application rate of 150 kg/hm^2 than at a nitrogen application rate of 105 kg/hm^2. Economic output was always higher using both CRU and U than using U only. The highest economic output was given using a 70∶ 30 CRU∶ U ratio.Increasing the amount of nitrogen added decreased the output efficiency（ per hm2） because CRU is expensive. Significant relationships were found between the yield increase rate and the proportion of CRU added（ regression equation y = 7. 429 x-185. 7,R^2= 0. 663） and between the total rainfall over the whole growth period and the proportion of CRU added（ y =-0. 087 1 x ＋ 112. 29,R^2= 0. 687 9）. These regression equations can be used to determine the appropriate proportion of CRU that should be added at a site,depending on the rainfall and target rice yield.