Search

The optimization of hydration temperature and duration were determined in six basmati and non-basmati paddy cultivars varying in grain size, shape, and amylose content based on kinetic parameters and effect of hydration temperature on physical, milling, textural and color attributes. Based on higher R2, lower Chi square and RMSE values, Peleg model fitted more suitably compared to Singh and Kulshrestha model. Hydration process significantly altered geometric, gravimetric and mechanical properties as evident by regression analysis. Physical properties except length and L/B ratio positively correlated with increasing hydration temperature. Head rice yield significantly improved in the hydrated treatments and showed a linear increase with the increase in hydration temperature. Head rice yield significantly correlated with hardness of grain (r = 0.684, p ≤ 0.01). Variable physico-chemical properties of cultivars led to establishment of cultivar specific optimum hydration temperature. Based on improvement in hardness, milling efficiency, head rice yield, color and textural attributes, the optimized temperature emerged as 75 °C for long slender grained cultivars (PB1509, PB1718, PS17) and 80 °C for medium grained cultivars (PD18, KJ, AL). The results revealed that optimum hydration temperature should be cultivar specific to get better output of parboiling process. [ABSTRACT FROM AUTHOR]

High head rice and low chalky grain percentages are key grain quality traits selected in developing rice cultivars. The objectives of this research were to characterize the phenotypic variation of head rice and chalky grain percentages in a diverse collection of rice accessions, identify single nucleotide polymorphism (SNP) markers associated with each of these traits using genome-wide association studies (GWAS), and identify putative candidate genes linked to the SNPs identified by GWAS. Diverse rice varieties, landraces, and breeding lines were grown at the Texas A&M AgriLife Research Center in Beaumont. Head rice percentages (HRP) and chalky grain percentages (CGP) of 195 and 199 non-waxy accessions were estimated in 2018 and 2019, respectively. Phenotypic data were analyzed along with 854,832 SNPs using three statistical models: mixed linear model (MLM), multi-locus mixed model (MLMM), and fixed and random model circulating probability unification (FarmCPU). Significant variations in HRP and CGP were observed between rice accessions. Two significant marker-trait associations (MTAs) were detected on chromosomes 1 and 2, respectively, based on best linear unbiased prediction (BLUP) values in 2018, while in 2019, one SNP was significantly associated with HRP in each of chromosomes 6, 8, 9, and 11, and two in chromosome 7. CGP was significantly associated with five SNPs located in chromosomes 2, 4, 6, and 8 in the 2018 study and ten SNPs in chromosomes 1, 2, 3, 4, 7, 8, 11, and 12 in the 2019 study. The SNPs are located within or linked to putative candidate genes involved in HRP and CGP. This study reports five and ten novel MTAs for HRP and CGP, respectively, while three and five MTAs co-located with previously reported quantitative trait loci for HRP and CGP, respectively. The validation of candidate genes for their roles in determining HRP and CGP is necessary to design functional molecular markers that can be used to effectively develop rice cultivars with desirable grain quality. [ABSTRACT FROM AUTHOR]

Zinc deficiency in rice can lead to reduced nutritional value and taste. This study investigates the potential of zinc oxide nanoparticles (ZnO NPs) as a foliar fertilizer during the jointing stage to improve rice yield, quality, and grain zinc enrichment. Over a two-year field experiment (2019–2020), six doses of ZnO NPs (ranging from 0 to 12 kg hm−2) were applied during the jointing stage (46 days after transplanting). The results revealed that foliar spraying of ZnO NPs increased the number of spikelets per spike and the thousand-grain weight by 7.4% to 9.2% and 4.2% to 7.1%, respectively, resulting in a substantial increase in rice yield. Furthermore, it led to a reduction in chalky white and chalky whiteness by 6.23% to 23.6% and 2.2% to 27.9%. ZnO NPs effectively boosted zinc content in rice grains while decreasing the phytic acid to zinc ratio, indicating improved zinc enrichment. Remarkably, protein and amylose content remained unaffected. These findings underscore the potential of ZnO NPs as a foliar fertilizer to enhance rice production, quality, and zinc enrichment. Further research can explore optimal application strategies and long-term effects for sustainable rice production. [ABSTRACT FROM AUTHOR]

Foliar application of Zinc (Zn) and Iron (Fe) fertilizers is known to be an effective solution to enhance rice grain yield and bio-fortification. The objectives of the current field experiment were to evaluate the effects of the foliar application of 0.5, 1, and 1.5 kg ha−1 of Zn and Fe glycine amino acid chelates and ZnSO4 on rice grain yield, protein, Zn, and Fe content of head rice (Hashemi cultivar) under both in the recommended and ½ of the recommended dose of NPK. The highest increase in the grain yield was recorded at 0.5 kgha−1 Fe-glycine amino acid chelate by about 29.2%. The maximum increase in protein and Zn content of head rice were recorded at 1.5 kg ha−1 of glycine amino acid-Zn chelate by about 10.5 and 22.3%, respectively. The most effective treatment to enhance the Fe content of head rice was the foliar application of 1.5 kg ha−1 of glycine amino acid-Fe chelate by about 32.6%. Interestingly, the foliar application of 1 kg ha−1 Zn-glycine amino acid chelate plus 1 kg ha−1 Fe-glycine amino acid chelate at the plots that received ½ of recommended NPK increased the grain yield, and protein, Zn and Fe content of head rice compared to control by about 7%, 18.5, 7.5, and 26.2, respectively. Therefore, regardless of rates and types, foliar application of Zn and/or Fe could enhance both rice yield, protein, Zn, and Fe content of head rice both in plots that received recommended and ½ of the recommended dose of NPK. [ABSTRACT FROM AUTHOR]

Non -uniform drying and head rice reduction due to non -movement of paddy in common fixed bed dryers is one of the basic problems in rice milling factories. In order to investigate and provide a suitable drying method with the approach of creating uniformity in drying process, reducing losses, and saving energy consumption, a two factorial experiment in completely randomized design (CRD) was used. The factors were the initial moisture content (IMF) of paddy at two levels (16 and 18%) and drying methodat 4 levels (one -way air flow, reverse air flow in 1 hour, 2 hours and 3 hours and then continuation of drying process the same as one -way airflow). The same drying air temperature and air velocity was considered for all treatments. In both moisture treatments, three hours reverse air flow drying has the highest head rice (75.7 -75.86%) and the lowest energy consumption (41 -49 MJ/kg water). The highest energy consumption with the amount of 79 and 67 MJ/kg water was belonging tothe one -way air flow treatment of paddy with high and low IMC (respectively).In one way airflow, dried paddy in 10 cm from the bottom layers of dryer has the lowest amount of head rice (63.65%). In both moisture treatments, the results of mixed layers showed that one hour reverse air flow drying with values of 68.28 -68.68% had the lowest head rice. Also, drying method had no significant effect (P>0.05) on the cooking quality. [ABSTRACT FROM AUTHOR]

Copyright of Indonesian Journal of Agronomy / Jurnal Agronomi Indonesia is the property of IPB University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Conventional parboiled rice requires many components such as boiler, steam pipe and auxiliary devices. To reduce the complexity of the process, in this work, the new method of producing parboiled rice by hot air fluidized bed (HAFB) and microwave-hot air fluidized bed (MWHAFB) was proposed and investigated. In the experiment, the soaked paddy with an initial moisture content of 47 ± 1% d.b. and initial grain temperatures of 32–65 °C were dried at the drying air temperatures of 110–170 °C with microwave powers of 0.8–4.0 W/gwet paddy (1.6–4.0 kW). The superficial air velocity at 4.6 m/s and bed depths of 5 cm (1 kgwet paddy) and 10 cm (2 kgwet paddy) were used. The experimental results showed that the drying time to reach an intermediate moisture content of 20 ± 2% d.b. was shorter with smaller bed depth, higher drying air temperature and higher microwave power. The MWHAFB and HAFB dryings could produce parboiled rice with a complete degree of starch gelatinization as the operating condition was suitable. The head rice quality of parboiled rice produced by MWHAFB and HAFB was not different. The parboiled rice had yellowish white for drying with excluding the tempering and had yellowish brown with including tempering as indicated by whiteness index (WI) with a value of 51–52. The consumption of energy was significantly lower in HAFB than that in the conventional process whilst the energy consumption between MWHAFB and conventional one was relatively comparable. [ABSTRACT FROM AUTHOR]

Copyright of Menoufia Journal of Plant Production is the property of Egyptian National Agricultural Library (ENAL) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Optimization study was carried out on the parboiling process variables for improving the milling quality of FARO-44 rice variety using Response Surface Methodology (RSM) in Central Composite Design (CCD). The variables studied were initial soaking temperature (IST), soaking time (SKt) and steaming time (STt) including their interactive effects.The range of the input variables studied were 70-90°C, 8-12hrs and 40-50minsfor initial soaking temperature, soaking time and steaming time respectively. For thisstudy, a total of twenty (20) randomized experimental runs comprising one (1) replicate of factorial point, one (1) replicate of axial point (alpha 2.7) and six (6) centre point in the design space. Analyses of variance (ANOVA) were performed on the experimental data sets and models were fitted for all the response variables generated.The result showed that the optimal parboiling variables were, 900C, 46mins and 10 hours,for initial soaking temperature, steaming time and soaking time respectively with their corresponding optimum response 58.7%, 6.7% and 58.1% for Head rice yield (based on parboiled paddy weight), breakage ratio and milled rice colour (based on illumination). The composite desirability is 0.793 which maximized the percentage Head rice yield (HRY) and milled rice colour (MRC) but minimized the percentage Breakage Ratio (BR). [ABSTRACT FROM AUTHOR]

Growing food crops to meet global demand and the search for more sustainable cropping systems are increasing the need for new cultivars in key production areas. This study presents the identification of rice traits putatively producing the largest yield benefits in five areas that markedly differ in terms of environmental conditions in the Philippines, India, China, Japan and Italy. The ecophysiological model WARM and sensitivity analysis techniques were used to evaluate phenotypic traits involved with light interception, photosynthetic efficiency, tolerance to abiotic stressors, resistance to fungal pathogens and grain quality. The analysis involved only model parameters that have a close relationship with phenotypic traits breeders are working on, to increase the in vivo feasibility of selected ideotypes. Current climate and future projections were considered, in the light of the resources required by breeding programs and of the role of weather variables in the identification of promising traits. Results suggest that breeding for traits involved with disease resistance, and tolerance to cold- and heat-induced spikelet sterility could provide benefits similar to those obtained from the improvement of traits involved with canopy structure and photosynthetic efficiency. In contrast, potential benefits deriving from improved grain quality traits are restricted by weather variability and markedly affected by G × E interactions. For this reason, district-specific ideotypes were identified using a new index accounting for both their productivity and feasibility. [ABSTRACT FROM AUTHOR]

A field experiment was carried out to determine the optimum sowing date and nitrogen (N) level for the scented rice cv. Pusa Sugandh-3. Twelve treatment combinations of 3 sowing dates, viz., 15th, 16th and 18th standard meteorological week (SMW) at an interval of 10 days and 4 nitrogen levels ('0', '40', '60' and '80' kg N ha-1) were tested randomized in split plot design with three replications. Significant highest plant height (98.56 cm), tillers m-2 (333.41), dry matter (98.38 q ha-1), panicles m-2 (310.05), spikelets panicle-1(130.25) and grains panicle-1 (98.55), grain yield (45.2 q ha-1), harvest index (41.20 %), head rice recovery (47.5 %) and B:C ratio (3.03) were recorded for the early sown 15th SMW crop. Among the different nitrogen levels tested significant highest plant height (98.12 cm), tillers m-2 (342.33) dry matter (100.68 q ha-1), panicles m-2 (321.83), spikelets panicle-1(132.83) grains panicle-1 (96.79), grain yield (48.0 q ha-1), harvest index (42.68 %), head rice recovery (44.54 %) and B:C ratio (3.38) were recorded with the application of 80 kg N ha-1.Therefore, the variety, Pusa Sugandh-3 should be sown earlier in season from 15th to 16th SMW and with nitrogen application of 60-80 kg N ha-1 for realizing economically higher grain yield and profit under the temperate climatic conditions of Kashmir valley. [ABSTRACT FROM AUTHOR]

The effects of the plant growth regulator trinexapac-ethyl (TE), conjoined with different seeding rates of rice (Oryza sativa L.) milling yields, were evaluated in Turkey between 2009 and 2010. Two rice cultivars (Osmancık-97 and Karadeniz), three seeding rates (400, 500, and 600 seeds m-2), and four doses of TE (0, 100, 200, and 300 g ai ha-1) were compared. The experiments were designed in a randomized block in factorial ordering with 3 replicates. Quality factors including head, cargo, and total rice milling yields, 1000 grain weight, and lodging score were evaluated. Head rice milling yield was affected significantly; however, no statistically significant difference was seen with respect to cargo rice and total milled rice by TE dose. The effect was predicted to depend on grain weight and lodging, which decreased rice milling yield. Seeding rate did not have a significant impact on milling yields. There was a significant correlation between milling yields (head rice and total milled rice but not cargo rice) and both 1000-grain weight and lodging. A seeding rate of 500 seeds m-2 was the optimum value among all seeding rates, and the highest milling yields were obtained from Osmancık-97. Irrespective of genotype and seeding rate, treatments with 100, 200, and 300 g TE ai ha-1 increased head rice milling yield. All doses of TE reduced 1000 grain weight and lodging. Regression analysis revealed that increasing TE doses raised head rice milling yield. [ABSTRACT FROM AUTHOR]

The volatile components of commercially milled head and broken rice samples and the effect of water washing on volatile components were investigated over 30 d of storage at 37°C and 70% relative humidity. Pentanal, pentanol, hexanal, pentylfuran, octanal, and nonanal were the major volatile components identified by gas chromatography-mass spectrometry (GC-MS) analysis in both head and broken rice samples. The concentration of volatile components was greater in broken rice than in head rice and increased significantly during the storage period for both rice types. Water washing was found to be effective in reducing the volatile components for both head and broken rice. [ABSTRACT FROM AUTHOR]

This study was conducted to determine the relative rate of FFA formation and lipid oxidation of unseparated (head and broken), head, and broken rice and the effect of water washing on the lipid quality of broken rice. A regression model was developed with surface FFA or conjugated diene (CD) content vs. incubation time to determine the rates of FFA formation and lipid oxidation. The surface lipid contents of unseparated, head, and broken rice were 0.40, 0.38, and 0.50% of rice, respectively. FFA formation during storage showed three phases: an initial rapid formation, followed by a period of very little or no formation, and finally a phase of gradual formation. In contrast, CD formation initially showed a slow increase but later increased gradually with storage time. The relative rates of FFA and CD formation of unseparated, head, and broken rice were 0.0028, 0.0027, and 0.0036 and 0.192, 0.188, and 0.377, respectively. Water washing reduced the rates of FFA formation and lipid oxidation of broken rice to 0.0015 and 0.2192 from initial values of 0.0031 and 0.369, respectively. Water washing appears to be a simple and practical means of lowering the rates of FFA formation and lipid oxidation in broken rice. [ABSTRACT FROM AUTHOR]

This study investigated the effect of soaking time on the quality of parboiled rice. The paddy was soaked in water at 25 and 80 °C for 15, 30, 45, 60 and 120 min. The soaked paddy was steamed, dried, stored and milled. With increasing soaking time a significant increase in water absorption and milling and head rice yield (hence reduction in broken rice) was observed. A significant difference in milling yield, at the 1% level, was obtained between the raw rice control and the hot soaked parboiled samples. A large reduction in fissured grain was observed after soaking. It is suggested that parboiling fills the void spaces and cements the cracks inside the endosperm, making the grain harder and minimizing internal fissuring and thereby breakage during milling. [ABSTRACT FROM AUTHOR]

The rice (Oryza sativa L.) crop in Arkansas is seeded from late March through early June each year. Farmers need new rice cultivars that not only produce both high rough rice yields and high head rice across this range of seeding dates but do so consistently. Thus, a seeding date study was conducted during 1994 and 1995 at Stuttgart, Arkansas, to study seeding date effects on rough rice yield and head rice and selection for stability. Fourteen rice cultivars were seeded at five dates ranging from late March through mid-June. Kang's yield-stability statistic was used to select cultivars for both high rough rice yields and high head rice as well as stability for both traits. Plant stands from March seedings of each year were significantly lower than for the later seeding dates. Maturity (days to 50 percent heading) was extended at the early seeding dates. Some rice cultivars, such as ‘LaGrue’, had lower and more variable head rice when seeded early. In the June seeding dates each year, ‘Kaybonnet’ produced rough rice yields that were more consistent with yields when planted at the earlier planting dates. ‘Bengal’, ‘Cypress’, ‘Kaybonnet’, and ‘Newbonnet’ were cultivars selected by Kang's stability statistic, which was targeted to select cultivars with stable, high rough rice yields and stable, high head rice. The validity of using Kang's yield-stability statistic for cultivar selection is also evident empirically by the adaptation and wide use of these four cultivars by southern U.S. rice producers. These results indicate that seeding date studies and stability analyses would be useful tools for rice breeders to identify cultivars that will be readily adapted and grown by rice producers. [ABSTRACT FROM AUTHOR]

High rough rice yields are important for the profitable production of rice (Oryza sativa L.). The value of rough rice is determined primarily by head rice (whole milled grains) and broken rice, together referred to as total milled rice. The objective of this study was to optimize selection for rough rice yield, head rice, and total milled rice using path-coefficient analysis and selection indices. Thirty-seven long grain pure lines were grown in an experiment at three Arkansas locations during 1993 and 1994. In another test, twenty-eight F1 hybrids obtained from an eight-parent half diallel of long-grain rices were grown at two locations in Arkansas during 1991. For the pure lines, path analysis revealed that rough rice yield was approximately twice as important in determining total milled rice/ha than head rice. Path analysis for the hybrids revealed that rough rice yield was an even greater component in determining total milled rice/ha. Based on yield components for hybrid rice, panicle density had the largest direct effect determining total milled rice/ha. Filled grain/panicle, grain weight, and head rice, in that order, were secondary, but positive, factors determining total milled rice/ha. A selection index for pure lines based only on selection for head rice was 19.2 percent as effective as selection for total milled rice/ha directly. When selection for total milled rice/ha was based solely on rough rice yield, selection was 82.7 percent as effective as selecting for total milled rice/ha directly. Selection to improve total milled rice/ha should concentrate on increasing both rough rice yield and head rice. Rough rice yield should receive greater priority than head rice in selection strategies. [ABSTRACT FROM AUTHOR]

The knowledge of engineering properties such as gravimetrical properties (1,000 grain mass, bulk density, true density, and porosity), dimensional properties (length, width, thickness, aspect ratio, surface area, geometric mean diameter, and sphericity), frictional properties (angle of repose and coefficient of friction), and aerodynamic properties (drag coefficient and terminal velocity) are necessary parameters related to machine design for different agricultural process operations such as handling, harvesting, threshing, cleaning, conveying, sorting, drying, processing, and storage. India is a vast country and contributes 20% of the total world’s rice production with cultivars ranging from the scented long grain ones to the sticky short grains. The Kashmir valley cultivates mainly short–medium bold varieties as temperate conditions in the valley are not suitable for the cultivation of long grain scented basmati rice. The most steps in cultivation and postharvest processing are manual and the aim of this work is to emphasize which variety sustains the processing steps to produce high yield quality rice for strengthening the economic conditions of the people. [ABSTRACT FROM AUTHOR]