Characterization of Rice Yield Based on Biomass and SPAD-Based Leaf Nitrogen for Large Genotype Plots.

The use of Unmanned Aerial Vehicle (UAV) images for biomass and nitrogen estimation offers multiple opportunities for improving rice yields. UAV images provide detailed, high-resolution visual information about vegetation properties, enabling the identification of phenotypic characteristics for selecting the best varieties, improving yield predictions, and supporting ecosystem monitoring and conservation efforts. In this study, an analysis of biomass and nitrogen is conducted on 59 rice plots selected at random from a more extensive trial comprising 400 rice genotypes. A UAV acquires multispectral reflectance channels across a rice field of subplots containing different genotypes. Based on the ground-truth data, yields are characterized for the 59 plots and correlated with the Vegetation Indices (VIs) calculated from the photogrammetric mapping. The VIs are weighted by the segmentation of the plants from the soil and used as a feature matrix to estimate, via machine learning models, the biomass and nitrogen of the selected rice genotypes. The genotype IR 93346 presented the highest yield with a biomass gain of 10,252.78 kg/ha and an average daily biomass gain above 49.92 g/day. The VIs with the highest correlations with the ground-truth variables were NDVI and SAVI for wet biomass, GNDVI and NDVI for dry biomass, GNDVI and SAVI for height, and NDVI and ARVI for nitrogen. The machine learning model that performed best in estimating the variables of the 59 plots was the Gaussian Process Regression (GPR) model with a correlation factor of 0.98 for wet biomass, 0.99 for dry biomass, and 1 for nitrogen. The results presented demonstrate that it is possible to characterize the yields of rice plots containing different genotypes through ground-truth data and VIs.

Reduced of mycotoxin levels in parboiled rice by using ozone and its effects on technological and chemical properties.

Contamination of foods by mycotoxins is a reality. However, emerging technologies such as ozonization can be used to reduce the levels of these contaminants. Thus, the aim of this study was to evaluate the effects of using ozone at different period and application times during the soaking step of parboiling process. Samples were analyzed for qualitative and quantitative analysis of mycotoxins, swelling power and solubility, head rice yield, protein solubility, cooking time, texturometric profile, colorimetric profile and defective grains. The results showed tha parboiled rice grains treated with ozone present significant reduction of mycotoxins contamination, regardless of the time and period of application and the mycotoxin evaluated. Regardig to technological properties, the samples treated with ozone in the final 3 h and for 5 h of soaking presented higher head rice yield, luminosity and hardness, with decreases in cooking time, percentage of defective grains and soluble protein.

Effect of drying conditions on the quality of IRGA 424 rice.

BACKROUND: The objective of this research was to investigate the effects of drying temperature (40, 50, and 60 °C), tempering time (40, 80, and 120 min), and initial moisture content at onset of tempering (15, 17, and 19% dry basis) on head rice yield, milled rice yield, and total processing time of IRGA 424 rice. RESULTS: The most significant effects were the drying temperature and its interaction with initial moisture content at onset of tempering. The optimum conditions predicted to reach the highest total yield (74.1%) included drying at 46.6 °C, 49 min of tempering time, and initial moisture content at onset of tempering of 19%. To achieve the maximum value of whole grain yield (52.9%), drying at 40 °C, 40 min of tempering, and an initial moisture content of 19% at the initiation of tempering were required. Under these conditions, the grain reached a moisture content of 13% in 84 min. CONCLUSION: Whole-grain rice yields may be maximized through the optimization of the drying process. This may result in a larger fraction of the crop entering the human food chain, enhancing the value of the crop, and resulting in a smaller fraction of broken grain, which commands a lower market value. © 2018 Society of Chemical Industry.

Households characteristics and perceptions of weather variability impact on rice yield: empirical analysis of small scale farmers in Tanzania / Características dos agregados familiares e percepções da variabilidade climática na produção de arroz: análise empírica de pequenos agricultores na Tanzânia

Rice farming is characterized by various factors including environmental and non-environmental factors. The current paper analyses the influence of households characteristics, and perceptions of weather variability on rice yield. Authors used primary data collected from small-scale rice farmers in the Mbeya region of Tanzania. Garret technique and Stata software were used for data analyses. Results confirmed that farmers education, marital status, gender, and land ownership have a positive influence on rice yield. Thus, for every 1% increase in each variable increases rice yield by 14%, 98%, 26%, and 21% respectively. Owing to empirical results on farmers perceptions, it is confirmed that if the drought period increased by 1%, would on average reduce rice yield by 20%. The majority of farmers (70%) have perceived that drought period reduced their rice yield. In addition, farmers used averagely less quantity of rice seeds which have impaired their rice yields. If farmers increased the seed quantity by 1%, rice yields would increase by 17%. Our findings also revealed that the previous market price has positive association with the next seasons rice yield. Therefore, our study concluded that among households variables and their perceptions have positive implications on rice yield; however, with the empirical analyses other variables were insignificant due to multicollinearity effects. Authors recommended to the government and other responsible organizations to capitalize on irrigation infrastructures, agricultural extension and technological services to restraint the enduring food insecurity coercions in Tanzania.(AU)

O presente trabalho analisa a influência das características das famílias e as percepções da variabilidade climática na produção de arroz. Os autores usaram dados primários coletados de pequenos produtores de arroz na região de Mbeya, na Tanzânia. A técnica de Garret e o software Stata foram utilizados para análise de dados. Os resultados confirmam que a educação do agricultor, estado civil, gênero e propriedade da terra têm uma influência positiva no rendimento do arroz. Assim, para cada aumento de 1% em cada variável aumenta a produção de arroz em 14%, 98%, 26% e 21%, respectivamente. Devido aos resultados empíricos sobre as percepções dos agricultores confirma-se que se o período de seca aumentar 1%, reduziria em média a produção de arroz em 20%. A maioria dos agricultores (70%) percebeu o período de seca para reduzir o rendimento do arroz. Além disso, os agricultores usam uma quantidade média menor de sementes de arroz que prejudicaram o rendimento do arroz. Se os agricultores aumentarem a quantidade de sementes em 1%, o rendimento do arroz aumentará em 17%. Nossas descobertas também revelaram que o preço de mercado anterior tem associação positiva com a produção de arroz das próximas safras. Portanto, nosso estudo conclui que entre as variáveis das famílias e suas percepções apresentam uma implicação positiva na produção de arroz, no entanto, com as análises empíricas, outras variáveis foram insignificantes devido aos efeitos de multicolinearidade. Os autores recomendaram ao governo e a outras organizações responsáveis que capitalizassem as infraestruturas de irrigação, a extensão agrícola e os serviços tecnológicos para conter as coercões duradouras de insegurança alimentar na Tanzânia.(AU)

Households' characteristics and perceptions of weather variability impact on rice yield: empirical analysis of small scale farmers in Tanzania / Características dos agregados familiares e percepções da variabilidade climática na produção de arroz: análise empírica de pequenos agricultores na Tanzânia

ABSTRACT: Rice farming is characterized by various factors including environmental and non-environmental factors. The current paper analyses the influence of households' characteristics, and perceptions of weather variability on rice yield. Authors used primary data collected from small-scale rice farmers in the Mbeya region of Tanzania. Garret technique and Stata software were used for data analyses. Results confirmed that farmer's education, marital status, gender, and land ownership have a positive influence on rice yield. Thus, for every 1% increase in each variable increases rice yield by 14%, 98%, 26%, and 21% respectively. Owing to empirical results on farmers' perceptions, it is confirmed that if the drought period increased by 1%, would on average reduce rice yield by 20%. The majority of farmers (70%) have perceived that drought period reduced their rice yield. In addition, farmers' used averagely less quantity of rice seeds which have impaired their rice yields. If farmers increased the seed quantity by 1%, rice yields would increase by 17%. Our findings also revealed that the previous market price has positive association with the next seasons' rice yield. Therefore, our study concluded that among households' variables and their perceptions have positive implications on rice yield; however, with the empirical analyses other variables were insignificant due to multicollinearity effects. Authors recommended to the government and other responsible organizations to capitalize on irrigation infrastructures, agricultural extension and technological services to restraint the enduring food insecurity coercions in Tanzania.

RESUMO: O presente trabalho analisa a influência das características das famílias e as percepções da variabilidade climática na produção de arroz. Os autores usaram dados primários coletados de pequenos produtores de arroz na região de Mbeya, na Tanzânia. A técnica de Garret e o software Stata foram utilizados para análise de dados. Os resultados confirmam que a educação do agricultor, estado civil, gênero e propriedade da terra têm uma influência positiva no rendimento do arroz. Assim, para cada aumento de 1% em cada variável aumenta a produção de arroz em 14%, 98%, 26% e 21%, respectivamente. Devido aos resultados empíricos sobre as percepções dos agricultores confirma-se que se o período de seca aumentar 1%, reduziria em média a produção de arroz em 20%. A maioria dos agricultores (70%) percebeu o período de seca para reduzir o rendimento do arroz. Além disso, os agricultores usam uma quantidade média menor de sementes de arroz que prejudicaram o rendimento do arroz. Se os agricultores aumentarem a quantidade de sementes em 1%, o rendimento do arroz aumentará em 17%. Nossas descobertas também revelaram que o preço de mercado anterior tem associação positiva com a produção de arroz das próximas safras. Portanto, nosso estudo conclui que entre as variáveis das famílias e suas percepções apresentam uma implicação positiva na produção de arroz, no entanto, com as análises empíricas, outras variáveis foram insignificantes devido aos efeitos de multicolinearidade. Os autores recomendaram ao governo e a outras organizações responsáveis que capitalizassem as infraestruturas de irrigação, a extensão agrícola e os serviços tecnológicos para conter as coercões duradouras de insegurança alimentar na Tanzânia.

Effects of Organic and Conventional Cropping Systems on Technological Properties and Phenolic Compounds of Freshly Harvested and Stored Rice.

This study compared the physicochemical and technological properties of the IRGA 410 rice cultivar, obtained from organic and conventional cropping systems, and showed its susceptibility to changes during storage at 0, 6, and 12 mo. The rice conventional cropping system exhibited greater protein, lipids, and ash levels, and a head rice yield. However, organic rice presented greater total carbohydrates, soluble protein, amylose content, 33% greater free phenolics, and phenolic acids, but exhibited a greater percentage of stained grains during the storage period. The free phenolic content of cooked rice was lower than the free phenolic content of the raw rice. By Liquid chromatography with mass spectrometer (LC-MS) were identified p-coumaric and ferulic acids in both fractions (free and bound). The content of p-coumaric acid and ferulic acid in bound fraction was higher in organic brown rice than in conventional brown rice. At 6 and 12 mo of storage, the main fungi found were Aspergillus sp. and Penicillium sp. Prior to storage, the Bipolaris sp. fungi was identified only in organic rice. For conventional rice, the infestation level by Aspergillus sp. increased from 3% to 70% at the 6th mo of storage. In addition to the advantage of organic rice being free of agrochemicals, this study revealed that natural plant defense compounds could be produced when the rice was subjected to more biotic and abiotic stresses. However, some disadvantages were observed, such as lower protein content and a greater percentage of soluble protein, which favored the breaking of rice in processing, and a greater percentage of grain stained before and during storage. PRACTICAL APPLICATION: The organic and conventional cropping systems affect the physicochemical and technological properties of rice grains, which is one of the main cereals grown and consumed in the world. This study shows the advantages and disadvantages of the cropping system in grain properties that are in the interest of both consumers and processing industries.

Grain quality of upland rice cultivars in response to cropping systems in the Brazilian tropical savanna

The industrial quality of grain is an important parameter to determine the commercial value of rice and can be influenced by water availability and type of cultivar. The present study aimed to evaluate the milling yield as well as the protein and nutrient contents of polished grains originated from two upland rice cultivars grown under rainfed and sprinkler-irrigated conditions. A randomized block design was used in a split-plot arrangement with eight replicates. Plots consisted of two cropping systems (rainfed and sprinkler-irrigated) with subplots consisting of two cultivars recommended for upland ecosystems (IAC 201 and Carajás). The sprinkler irrigation system increased upland rice milling (8.0%) and head rice yield (23.7%), for years with hot and dry weather spells occurring during the reproductive and maturation stages. Under conditions of lower water availability, the Carajás cultivar showed a milled yield value 5.1% higher than that of cultivar IAC 201. Lower water availability provided increases in protein, N, P, Ca, Mg, Fe, and Zn contents but reductions in S and Cu in the polished grains. Cultivars IAC 201 and Carajás had similar nutrient contents in the polished grains.

A qualidade industrial do grão beneficiado é parâmetro importante para determinar o valor de comercialização do arroz e pode estar relacionada com a disponibilidade hídrica e o cultivar utilizado. O trabalho teve como objetivo avaliar o rendimento de engenho e teores de nutrientes e proteínas nos grãos brunidos provenientes de dois cultivares de arroz de terras altas conduzidos sob condições de sequeiro e irrigados por aspersão. O delineamento experimental utilizado foi o de blocos ao acaso, em esquema de parcela subdividida, com oito repetições. As parcelas foram constituídas por dois sistemas de cultivo (sequeiro e irrigado por aspersão) e as subparcelas por dois cultivares indicados para o ecossistema de terras altas (IAC 201 e Carajás). A irrigação por aspersão aumentou o rendimento de engenho (8,0%) e de grãos inteiros (23,7%) do arroz de terras altas, em anos com ocorrência de veranicos nas fases reprodutiva e de maturação. Sob condições de baixa disponibilidade hídrica o cultivar Carajás apresenta rendimento de benefício 5,1% maior do que o cultivar IAC 201. A baixa disponibilidade hídrica promove acréscimo nos teores de proteína, N, P, Ca, Mg, Fe e Zn nos grãos brunidos, porém reduz os teores de S e Cu. Os teores de nutrientes nos grãos brunidos dos cultivares IAC 201 e Carajás são similares.

Grain quality of upland rice cultivars in response to cropping systems in the Brazilian tropical savanna

The industrial quality of grain is an important parameter to determine the commercial value of rice and can be influenced by water availability and type of cultivar. The present study aimed to evaluate the milling yield as well as the protein and nutrient contents of polished grains originated from two upland rice cultivars grown under rainfed and sprinkler-irrigated conditions. A randomized block design was used in a split-plot arrangement with eight replicates. Plots consisted of two cropping systems (rainfed and sprinkler-irrigated) with subplots consisting of two cultivars recommended for upland ecosystems (IAC 201 and Carajás). The sprinkler irrigation system increased upland rice milling (8.0%) and head rice yield (23.7%), for years with hot and dry weather spells occurring during the reproductive and maturation stages. Under conditions of lower water availability, the Carajás cultivar showed a milled yield value 5.1% higher than that of cultivar IAC 201. Lower water availability provided increases in protein, N, P, Ca, Mg, Fe, and Zn contents but reductions in S and Cu in the polished grains. Cultivars IAC 201 and Carajás had similar nutrient contents in the polished grains.

A qualidade industrial do grão beneficiado é parâmetro importante para determinar o valor de comercialização do arroz e pode estar relacionada com a disponibilidade hídrica e o cultivar utilizado. O trabalho teve como objetivo avaliar o rendimento de engenho e teores de nutrientes e proteínas nos grãos brunidos provenientes de dois cultivares de arroz de terras altas conduzidos sob condições de sequeiro e irrigados por aspersão. O delineamento experimental utilizado foi o de blocos ao acaso, em esquema de parcela subdividida, com oito repetições. As parcelas foram constituídas por dois sistemas de cultivo (sequeiro e irrigado por aspersão) e as subparcelas por dois cultivares indicados para o ecossistema de terras altas (IAC 201 e Carajás). A irrigação por aspersão aumentou o rendimento de engenho (8,0%) e de grãos inteiros (23,7%) do arroz de terras altas, em anos com ocorrência de veranicos nas fases reprodutiva e de maturação. Sob condições de baixa disponibilidade hídrica o cultivar Carajás apresenta rendimento de benefício 5,1% maior do que o cultivar IAC 201. A baixa disponibilidade hídrica promove acréscimo nos teores de proteína, N, P, Ca, Mg, Fe e Zn nos grãos brunidos, porém reduz os teores de S e Cu. Os teores de nutrientes nos grãos brunidos dos cultivares IAC 201 e Carajás são similares.