Short-term daily forecasting of crop evapotranspiration of rice using public weather forecasts

Accurate forecasts of daily crop evapotranspiration (ET_c) are essential for real-time irrigation management and water resource allocation. This paper presents a method for the short-term forecasting of ET_c using a single-crop coefficient approach and public weather forecasts. Temperature forecasts with a 7-day lead time in 2013–2015 were retrieved and entered into a calibrated Hargreaves–Samani model to compute daily reference evapotranspiration (ET₀) forecasts, while crop coefficient (K_c) empirical values were estimated from both observed ET_c value and calculated ET₀ values using the Penman–Monteith equation for the period of 2010–2012. Daily ET_c forecasts of irrigated double-cropping rice were determined for three growing seasons during the period of 2013–2015 and were compared with ET_c values measured by the weighing lysimeters at the Jiangxi experimental irrigation station in southeastern China. During the early rice season, the average mean absolute error (MAE) and root-mean-square-error (RMSE) values of ET_c forecasts ranged from 0.95 to 1.06 mm day^?1 and from 1.18 to 1.31 mm day^?1, respectively, and the average correlation coefficient (R) ranged from 0.39 to 0.54; for late rice, the average MAE and RMSE values ranged from 1.01 to 1.09 mm day^?1 and from 1.32 to 1.40 mm day^?1, respectively, and the average R value ranged from 0.54 to 0.58. There could be three factors responsible for errors in ET_c forecasts, including temperature forecast errors, K_c value errors and neglected meteorological variables in the HS model, including wind speed and relative humidity. In addition, ET_c was more sensitive to changes in temperature than K_c. The overall results indicated that it is appropriate to forecast ET_c with the proposed model for real-time irrigation management and water resource allocation.     

Thermo-Mechanical Characterization of a Thermoplastic Copolyetherester (TPC): Experimental Investigation

In this article, the thermo-mechanical characterization of poly(butylene terephthalate)/poly(tetramethylene oxide) (PBT/PTMO) is studied by thermal analysis, dynamic mechanical analysis, and uniaxial tensile tests. The results of poly(ether esters) show that the melting temperature is equal to T _m =193 °C, which is 31 °C, lower than that of the melting temperature of poly(butylene terephthalate) (PBT). Its glass transition temperature, T _g is equal to -61 °C, determined by DMA. The melting and cooling temperatures (T _m , T _c ) after aging at T₀+48 h and T₀+week are virtually unchanged. Moreover, the results of the tensile tests show that the effect of the low deformation rate reduces the friction resulting from the sliding mechanisms between the amorphous and crystalline parts.     

Implications of the Red Beet Ripening on the Colour and Betalain Composition Relationships

The evolution during ripening of Beta vulgaris (var. Pablo) on colour and betalain composition, not previously conducted in conjunction in red beets, has been examined. According to the results, it could be asserted that the ripening stage significantly (p?<?0.05) influenced on all the studied parameters. On the basis of the betalain content, the optimum ripening stage corresponded to a medium weigh-to-calibre ratio, in the light of the significantly (p?<?0.05) higher content of betalains, especially betanin and vulgaxanthin I. Moreover, colour attributes also differed during ripening, having the medium-ripened beetroots a significantly (p?<?0.05) more reddish hue (h_ab) and lower lightness (L*), probably due to the higher content of betaxanthins in this stage. The colour differences among red beets in the stage II and the rest of stages were visually appreciable (ΔE*_ab?>?3) and mainly qualitative. A new range of opportunities for diversification of colorant market, from a nutritional and colorimetric point of view, could be possible by employing red beets with different stages of ripening.     

Petiole nitrate content of Maine-grown Russet Burbank and Shepody potatoes in response to varying nitrogen rate

Russet Burbank and Shepody potatoes were grown with at-planting nitrogen fertilizer rates varying from 0 to 270 kg ha^?1 following small grains and red clover. Petiole samples were collected from the 4th and 5th leaflets at four to six dates each during the 1986 to 1989 growing seasons. The samples were dried and analyzed for NO ₃ ^? N content. Petiole NO ₃ ^? N levels were strongly related to nitrogen rate regardless of cultivar, growing season, and cropping system. Differences among treatments and NO ₃ ^? N content varied substantially as the growing season progressed with petiole NO ₃ ^? N levels declining rapidly in underfertilized plots as the plants aged. Petiole NO ₃ ^? N levels were higher at midseason following red clover than following small grains. Sampling 50 to 60 days after planting (DAP) is most appropriate as a tool for scheduling supplemental nitrogen applications. At 50 DAP, critical petiole NO ₃ ^? N levels were 1.6 and 1.7% for Russet Burbank and Shepody, respectively. Petiole NO ₃ ^? N levels above 2.2% at 50 DAP resulted in lower yields of Russet Burbank than when petiole NO ₃ ^? N levels were in the 1.6 to 2.2% range. Petiole NO ₃ ^? N testing should be particularly useful as a diagnostic tool in management strategies which make maximum use of previous crop residues, organic amendments, and soil reserves as nitrogen sources.     

Prediction of water quality effect on saturated hydraulic conductivity of soil by artificial neural networks

This study was conducted to investigate the impact of water salinity (EC_w) and sodicity (SAR_w) on saturated (K_s) and relative (K_r) hydraulic conductivities in two clay (C) and sandy clay loam (SCL) soils. The results showed that the K_s decreased with increasing SAR_w, and in all of water quality treatments, the K_s of SCL soil was higher than that of the C soil. Sodicity effect (even at high SAR_w) on the K_r of clay soil was minimized by high salinity. Although K_r of both soils similarly responded to EC_w and SAR_w, microstructure of clay soil was more sensitive to water quality. Effect of EC_w on soil structure was greater than that of SAR_w. In order to assess the applicability of artificial neural networks (ANNs) in estimating K_s and K_r, two types of FFBP and CFBP ANNs and two training algorithms, namely Levenberg–Marquardt (LM) and Bayesian regulation, were employed with two strategies of uniform threshold and different threshold functions. Multiple linear regressions were also used for K_s and K_r prediction. Based on the ANN results of second strategy, best topology (4–5–4–1) was belonged to CFBP network with LM algorithm, LOGSIG–LOGSIG–TANSIG threshold functions, and values of MAE and R² are equal to 0.1761 and 0.9945, respectively. Overall, the efficacy of ANNs is much greater than regression method for K_s prediction.     

Effects of various organic amendments on organic carbon pools and water stable aggregates under a scented rice–potato–onion cropping system

Pools of organic carbon are quantified from the soil samples under scented rice crop from different soil layers (0–10, 10–20, and 20–30 cm) under 9 years’ long-term trials with five treatments in scented rice–potato–onion cropping system. These treatments were 100 % NPK (NPK), 50 % recommended NPK through mineral fertilizers + 50 % N as FYM (NPK + FYM), FYM + vermicompost (VC) + neem cake (NC) each equivalent to one-third of recommended N (FYM + VC + NC), 50 % N as FYM + biofertilizer for N + bone meal to substitute phosphorus requirement of crops + phosphate solubilizing bacteria (FYM + BFN + BM + PSB), FYM + vermicompost + neem cake each equivalent to 1/3rd of recommended N + PSB (FYM + VC + NC + PSB). SMBC (479 mg kg^?1), HWEOC (373 mg kg^?1), CWSCHO (235 mg kg^?1), HWSCHO (839 mg kg^?1), and ASCHO (180 mg kg^?1) were found to be the highest in the soil treated with FYM + VC + NC + PSB and the lowest with NPK. The quantity of hot water-extractable carbohydrate content is highest amongst cold water, dilute acid and hot water extractable carbohydrate that decreases with the soil depth irrespective of treatments, except CWEOC. Soil microbial biomass carbon (SMBC) shows significant correlation with CWEOC (r = 0.60**), HWEOC (r = 0.94**), CWSCHO (r = 0.75**), HWSCHO (r = 0.83**), and ASCHO (r = 0.83**) that primed for better aggregate stability irrespective of soil layers up to 30 cm depth. This indicates that labile carbon pools, most specifically water-soluble carbon, carbohydrate, microbial biomass, could be a suitable indicator for evaluation of soil quality, particularly in relation to soil aggregation.     

Colorimetric Analysis of <Emphasis Type="Italic">Hibiscus</Emphasis> Beverages and their Potential Antioxidant Properties

In food industry, roselle beverages and their subproducts could be functional ingredients since they are an excellent source of bioactive compounds with improved performance due to their important anthocyanins content. The aim of this study was to analyze anthocyanin content and antioxidant properties of aqueous infusions elaborated with color contrasting Hibiscus materials and design a mathematical model in order to predict color-composition relationship. Color measurements of beverages from roselle (Negra, Sudan and Rosa) were made by transmission spectrophotometry, anthocyanins quantification was determined by HPLC, and antioxidant potential was evaluated by in vitro methods (ABTS and FRAP assays). Beverages prepared with particle size minor of 250 μm presented until 4- and 2- times more anthocyanins content and antioxidant capacity respectively, in comparison to beverages prepared with powders with particle size major of 750 μm. Positive correlations among pigments composition and color parameters were found (p?<?0.05), showing that anthocyanins content, antioxidant capacity, C*_ab and h_ab values increased in relation with the smallest particle size of flours. Also, mathematical models were stablished to predict anthocyanin content (r?≥?0.97) and antioxidant capacity (r?≥?0.89) from color data; we propose equations for quick estimation of the antioxidant capacity in the Hibiscus beverages with high anthocyanin content. The obtained models could be an important tool to be used in food industry for pigment characterization or functional compounds with potential health benefits.     

Phenotypic and Genomic Modifications Associated with <Emphasis Type="Italic">Globodera pallida</Emphasis> Adaptation to Potato Resistances

Studying phenotypic and genomic modifications associated with pathogen adaptation to resistance is a crucial step to better understand and anticipate resistance breakdown. This short review summarizes recent results obtained using experimentally evolved populations of the potato cyst nematode Globodera pallida. In a first step, the variability of resistance durability was explored in four different potato genotypes carrying the resistance quantitative trait loci (QTL) GpaV_vrn originating from Solanum vernei but differing by their genetic background. The consequences of the adaptation to resistance in terms of local adaptation, cross-virulence and virulence cost were then investigated. Finally, a genome scan approach was performed in order to identify the genomic regions involved in this adaptation. Results showed that nematode populations were able to adapt to the QTL GpaV_vrn, and that the plant genetic background has a strong impact on resistance durability. A trade-off between the adaptations to different resistant potato genotypes was detected, and we also showed that adaptation to the resistance QTL GpaV_vrn from S. vernei did not allow adaptation to the colinear locus from S. sparsipilum (GpaV_spl). Unexpectedly, the adaptation to resistance led to an increase of virulent individual’s fitness on a susceptible host. Moreover, the genome scan approach allowed the highlighting of candidate genomic regions involved in adaptation to host plant resistance. This review shows that experimental evolution is an interesting tool to anticipate the adaptation of pathogen populations and could be very useful for identifying durable strategies for resistance deployment.     

Effect of drip irrigation on soil nutrients changes of saline–sodic soils in the Songnen Plain

A field experiment was carried out to research the changes and spatial distributions of soil nutrients in saline–sodic soil for different number of cultivated years under drip irrigation. The distributions of available potassium (AK), available phosphorus (AP), nitrate nitrogen (NO₃ ^?–N), ammonium nitrogen (NH₄ ⁺–N), as well as the amount of total nitrogen (TN), total phosphorus (TP) and organic carbon (OC) in the 0–40 cm soil layers in saline–sodic soils planted with Leymus chinensis for 1, 2, and 3 years were studied. The results showed that the distance from the emitter had an obvious effect on soil nutrients. Drip irrigation had substantial effects on levels of AK, AP, and NO₃ ^?–N. The contents of AK, AP, and NO₃ ^?–N were very high in the area near the emitter in the horizontal direction. In the vertical direction, levels of all of the available and total soil nutrients decreased with increased soil depth. Levels of AK, AP, NO₃ ^?–N, NH₄ ⁺–N, TN, TP, and OC all increased with continued cultivation of crops on saline–sodic soil using drip irrigation. Compared to the nutrients found in soils from the natural L. chinensis grasslands, the contents of AK and TP were higher in the drip-irrigated soils, although the contents of AP, NO₃ ^?–N, and NH₄ ⁺–N were broadly comparable. Given the rate of improvements in nutrient levels, we forecast that the nutrients in drip-irrigated saline–sodic soils should match those of the natural L. chinensis grasslands after 3–6 years of cultivation.     

The Relationship Between Active Oxygen Metabolism and Resistance to Late Blight in Potato

The relationship between active oxygen metabolism and resistance to late blight (Phytophthora infestans) in potato (Solanum tuberosum L.) was studied for 72 h post-inoculation by comparing three resistant cultivars (low disease index) with three susceptible ones (high disease index). Activities of superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX), and the content of ascorbic acid (ASA), were higher in the resistant cultivars than in the susceptible ones. The production rate of the superoxide anion radical (O₂^?) was lower in the resistant cultivars than in the susceptible ones. These changes, which were associated with the potato plant’s response to infection with P. infestans, provide some insight into the physiological basis of resistance and may also provide a screening tool for resistance to late blight.     

Applicability of APSIM to capture the effectiveness of irrigation management decisions in rice-based cropping sequence in the Upper-Gangetic Plains of India

Rice–wheat (RW) production system, which covers over 13.5 million ha in the Indo-Gangetic Plains of south Asia, is vital for food and nutritional security and livelihood of millions of poor people in this part of the region. Availability of irrigation water under projected climate change scenarios is a great concern, and demonstration of the impact of different irrigation regimes on rice, wheat, and system yields is essential to adopt suitable water saving technologies to minimize risk. This study tested the ability of the agricultural production systems simulator (APSIM) model to simulate the effects of different irrigation regimes on yield, irrigation water requirement, and irrigation water productivity (WP_i) of rice, wheat, and RW system in upper-gangetic plains of India. The long-term simulated rice yield showed a steadily declining trend at an average rate of 120 kg ha^?1 yr^?1 (R ² = 0.94, p < 0.05), while long-term simulated wheat yields showed a lower declining trend at an average rate of 48 kg ha^?1 yr^?1 (R ² = 0.48, p < 0.05). The highest WP_i of 8.31 kg ha^?1 mm^?1 was observed under RW system with the rice irrigation (IR) regime of 8 days alternate wetting and drying (AWD) and five irrigations for wheat with a yield penalty of 25.5 %. The next highest WP_i was observed in the treatment with a 5-day AWD regime in rice and five irrigations for wheat, with a yield penalty of 20.1 %. Thus, we can suggest that a 5-day AWD irrigation regime for rice combined with five irrigations during wheat could be the best option under water limiting situations.     

Water and air temperature impacts on rice (<Emphasis Type="Italic">Oryza sativa</Emphasis>) phenology

Air temperature (T_a) is commonly used for modeling rice phenology. However, since the growing point of rice is under water during the vegetative and the early part of the reproductive period, water temperature (T_w) is likely to have a greater influence on crop developmental rates than T_a during this period. To test this hypothesis, we monitored T_w, T_a, and crop phenology in three commercial irrigated rice fields in California, USA. Sampling locations were set up on along a transect from the water inlet into the field. (Water warms up as it moves into the field.) T_a averaged 22.7 °C across sampling locations within each field, but average seasonal T_w increased from 22 °C near the inlet to 23.4 °C furthest away from the inlet. Relative to T_w furthest from the inlet, low T_w near the inlet delayed time to panicle initiation (PI 5 days) and heading (HD 8 days) and the appearance of one yellow hull on the main stem panicle (R7 9 days). Using T_w instead of T_a when the active growing point is under water until booting (midway between PI and HD) in a thermal time model improved accuracy (root-mean-square error, RMSE) for predicting time to PI by 2.5 days and HD by 1.6 days and R7 by 1.8 days. This model was further validated under more typical field conditions (i.e., not close to cold water inlets) in six locations in California. Under these conditions, average T_w was 2.6 °C higher than T_a between planting and booting, primarily due to higher daily maximum T_w values. Using T_w in the model until booting improved RMSE by 1.2 days in predicting time to HD. Using T_w instead of T_a during this period could improve the accuracy of rice phenology models.     

Mechanical and Dynamic Mechanical Studies on Epoxy-Cobaltous Sulfate Polymer Hybrids

Cobaltous sulfate heptahydrate (CoSO₄·7H₂O) was incorporated as filler into diglycidyl ether of bisphenol A (DGEBA) based epoxy resin system, to prepare organic-inorganic polymer hybrid materials. Mechanical tensile studies and dynamic mechanical analysis (DMA) were carried out in order to study the static and dynamic mechanical properties of the prepared hybrid films. Mechanical tensile studies were carried out at room temperature, at a test speed of 30 mm/min. Highest tensile strength of 24.74±2.42 MPa was achieved for 4.44 wt% filler level (FL), along with an increase in the value of Young’s modulus. Storage modulus (E′), loss modulus (E″), damping factor (tan δ) were obtained by DMA studies. Glass transition temperature (T_g) was obtained for pure epoxy and filled epoxy, for various FLs varying from 0.28 wt% to 5.00 wt%. Pure epoxy showed highest T_g value compared to filled epoxy hybrids. Highest storage modulus of 9.5 GPa was obtained for 2.22 wt% FL, which also showed highest loss modulus peak. Parameters like effectiveness coefficient (C) and crosslink density were calculated from the storage modulus data. Loss modulus and tan δ curves were analyzed to study the energy dissipation properties of prepared hybrid films. Activation energy (E_a) value for glass transition was obtained from damping factor (tan δ), which showed highest E_a value of 630.5 kJmol^-1, for 4.44 wt% FL. DMA studies for various FLs were carried out at different test frequencies in order to study the changes in dynamic mechanical properties of the prepared hybrid materials with respect to frequency     

The Low Potential of Teff (<Emphasis Type="Italic">Eragrostis tef</Emphasis>) as an Inoculum Source for <Emphasis Type="Italic">Verticillium dahliae</Emphasis>

Teff (Eragrostis tef) is a fine stemmed annual grass and gluten free small grain that is of interest as a forage, cover, or a rotation crop. Little is known about the susceptibility of teff to many diseases. Teff could be grown in rotation with potato in the northwestern United States provided teff cultivation is economical and does not increase soil populations for pathogens affecting rotation crops such as Verticillium dahliae. Verticillium dahliae infects a wide range of dicotyledonous plants, making it one of the most important fungal pathogens of crop plants in North America, including potato. The objective of this study was to quantify the susceptibility of teff to eight V. dahliae isolates and compare the susceptibility of teff to eggplant. Teff was confirmed as a host for V. dahliae, as indicated by the presence of microsclerotia in teff stems and roots after artificial inoculation in two years of greenhouse studies. The number of microsclerotia produced in teff did not differ between mint and potato pathotypes of V. dahliae. No V. dahliae isolate produced significantly greater numbers of microsclerotia than any of the seven other isolates tested in a two-year study. Microsclerotia production of V. dahliae in teff was consistently less than in susceptible eggplant cv. Night shadow in both greenhouse experiments (P?<?0.02). It is unlikely that teff infected by V. dahliae will proliferate microsclerotia of mint or potato-aggressive pathotypes, especially when compared to susceptible eggplant cultivars.     

Natural Dyeing of Wool by Madder (<Emphasis Type="Italic">Rubia tinctorum L</Emphasis>.) Root Extract Using Tannin-based Biomordants: Colorimetric,Fastness and Tensile Assay

In this work, the natural dyeing behavior of woollen yarn with madder (Rubia tinctorum L.) root extract was studied. The effects of different tannin-rich plants (Rhus coriaria, Eucalyptus, Terminalia chebula, Quercus castaneifolia, Pomegranate) extract as biomordants and alum (as a chemical mordant) with two mordanting procedures (pre- and metamordanting) on color characteristics of the dyed samples were also investigated. The CIEDE2000 values, color strength (K/S), washing fastness and tensile property of the mordanted and dyed samples were assessed. Visually, a range of hues from orange to brownish-red were obtained. In general, pre-biomordanted samples with Rhus coriaria (10 %owf), Eucalyptus (10 %owf), Terminalia chebula (5 %owf), Quercus castaneifolia (5 %owf) and Pomegranate (5 %owf) showed almost the same color difference (ΔE₀₀) and wash fastness values compared to those treated with 3 %owf alum. Finally, it was concluded from the comparative studies that the biomordants have good potential to be considered as alternatives to the common chemical mordants.     

增铵营养对玉米品质影响初探

试验利用盆栽,选用远征808(收敛型)和四单19(平展型)作试验材料,研究了增铵营养对玉米子粒中蛋白质、淀粉和可溶性糖含量的影响.在氮素水平一致的条件下,设6个处理,NO3--N和NH4+-N比例分别是3:0、2:1、1:1、1:2、0:3及对照(不施氮).试验表明,增铵营养可以提高玉米子粒中蛋白质含量,但不同类型品种表现有差异,远征808在NO₃^--N和NNH₄⁺-N比例为2:1时蛋白质含量最高,而四单19在1:2时     

Antioxidant Properties of Extracts Obtained from Raw,Dry-roasted,and Oil-roasted US Peanuts of Commercial Importance

Raw, skinless peanut kernels from US commercial production lines were dry- and oil-roasted according to standard industrial practices. Eighty percent (v/v) methanolic extracts from the peanut cultivars were prepared and characterized by RP-HPLC: five predominant compounds were found comprising free p-coumaric acid and potential p-coumaric acid derivatives, as elucidated by DAD-UV spectra with comparisons to those of commercial standards. A Spanish high-oleic peanut possessed the greatest naturally-occurring level of p-coumaric acid and its derivatives, followed by a high-oleic Runner, a normal Runner, and a Virginia peanut. Upon thermal processing, p-coumaric acid was liberated at the expense of its derivatives according to the relationship: oil roasting > dry roasting > raw. A high-oleic Runner exhibited the greatest increase (～785%) in free p-coumaric acid levels after oil roasting. For many of the samples from the 2007 crop, processing increased the TPC and antioxidant capacities in the order of raw < dry roast < oil roast, but results were cultivar dependent. Oil-roasted peanuts were more effective at scavenging O₂ ^●- than their dry-roasted counterparts, as determined by a photochemiluminescence assay. Overall findings indicate that although thermal processing altered the composition of peanut kernel antioxidants, TPC values and radical-scavenging activities are preserved. Depending on peanut type, cultivar, and harvest date, enhanced antioxidant capacities can result.     

Synthesis of hydrophilic copolyesters and the characterization of their moisture-related cooling properties

A series of copolyesters (Co-PETs) containing poly(ethylene glycol) (PEG), 5-sodiumsulfodimethyl isophthalate (DMS), and dimethyl isophthalate (DMI) were synthesized via the conventional two-step melt-polycondensation method. The synthesized Co-PETs were characterized by ¹H-NMR spectroscopy, FT-IR spectroscopy, differential scanning calorimeter (DSC), and thermogravimetric analyzer (TGA). The DSC results showed that the melting temperature (T _m) and the heats of fusion (ΔH _m) of Co-PETs decreased with increasing the DMS content in Co-PET, while the inclusion of PEG did not affect their thermal properties significantly. The water absorption and the water contact angle of the Co-PET films were found to be significantly affected by the DMS content rather than PEG content. The moisture-related cooling properties of the fabric samples made of Co-PET 5 as well as PET were evaluated by using liquid moisture management tester (MMT) and Q _max measurements. The MMT and Q _max results indicated that Co-PET 5 fabric containing DMS 1.0 mol% and PEG 10.0 wt% in Co-PET seemed to be a good candidate for the fabric having durable cooling effects.