Effects of spatial pattern and cultivar on weed control and grain yield in rice at reduced rates of herbicide / Efeitos do padrão espacial e cultivar on controle de plantas daninhas e rendimento de grãos do arroz com taxas reduzidas de herbicida

To evaluate the effects of herbicide rate, cultivar, and spatial pattern on rice grain yield and weed suppression, a field experiment was conducted on a lowland rice field at the Rice Research Station of Tonekabon, north of Iran, in 2011. The experimental design was a split plot-factorial where the whole plot portion was a randomized complete block with three replicates. Main plots were pretilachlor rates (0, 0.5, 1, 1.5, 2 L ha-1 of pretilachlor). The subplots were factorial combinations of two crop spatial patterns (uniform and wide-row planting patterns, 20× 20 and 30 × 13 cm, respectively) and two traditional rice cultivars ('Hashemi' and 'Deylamani'). Regardless of cultivar and spatial pattern, rice grain and biological yields, panicle number per m2, leaf area index, and herbicide efficacy increased, while weed biomass decreased with increasing pretilachlor application rate. Rice grain and biological yields, panicle number per m2, leaf area index, and herbicide efficacy were significantly greater in uniform planting pattern than in wide-row planting pattern when averaged over cultivars and pretilachlor rates. Moreover, uniform planting pattern of rice plants suppressed weeds 39% better than wide-row planting pattern as averaged across pretilchlor rates and cultivars. 'Deylamani' produced grater grain and biological yields, panicle number per m2, leaf area index than 'Hashemi' as averaged across pretilachlor rates and spatial patterns. This experiment illustrated that uniform spatial pattern increased weed suppression, herbicide efficacy, and grain yield.

Para avaliar os efeitos da taxa de herbicida, cultivar e padrão espacial em arroz produção de grãos e supressão de plantas daninhas , um experimento de campo foi realizado em um campo de arroz irrigado na Estação de Pesquisa do Arroz de Tonekabon , norte do Irã, em 2011. O delineamento experimental foi uma fração de lote - fatorial, onde toda a parte de enredo foi em blocos casualizados com três repetições. As parcelas foram as taxas pretilaclor (0, 0.5, 1, 1.5 , 2 L ha-1 de pretilaclor) . As subparcelas foram combinações fatoriais de dois padrões de culturas espaciais (uniformes e padrões de plantio em toda a linha, 20 × 20 e 30 × 13 cm , respectivamente) e duas cultivares de arroz tradicionais (' Hashemi ' e ' Deylamani ') . Independentemente de cultivar e padrão espacial , grãos de arroz e os rendimentos biológicos , número de panículas por m2 , o índice de área foliar e eficácia do herbicida aumentou, enquanto a biomassa de plantas daninhas diminuiu com o aumento da taxa de aplicação pretilaclor . O grão de arroz e os rendimentos biológicos , número de panículas por m2 , o índice de área foliar e eficácia do herbicida foram significativamente maiores no padrão de plantio uniforme do que em toda a linha de plantio padrão quando calculados sobre cultivares e taxas pretilaclor . Além disso, o plantio uniforme padrão de plantas de arroz suprimida ervas daninhas 39% melhor do que em toda a linha de plantio padrão como média entre as taxas de pretilchlor e cultivares . ' Deylamani "produzido grão ralador e os rendimentos biológicos , número de panículas por m2 , índice de área foliar do que" Hashemi ", como média entre as taxas de pretilaclor e padrões espaciais. Este experimento mostrou que padrão espacial uniforme aumento supressão de plantas daninhas , eficácia do herbicida , e rendimento de grãos.

Minerales, ácido fítico y γ-oryzanol en harinas integrales y salvados de tres variedades de arroz (oryza sativa l) cultivadas en venezuela / Minerals, phytic acid and γ-oryzanol in whole wheat flour and bran of three varieties of rice (oryza sativa l) grown in venezuela

El propósito de esta investigación fue determinar el contenido de algunos minerales, de ácido fítico y de γ-oryzanol en harinas integrales y salvados de tres cultivares (Cimarrón, Fonaiap 1 y Zeta 15) de arroz (Oryza sativa L) cosechados en Venezuela. Los minerales (Ca, Mg, Fe y Zn) fueron cuantificados por espectrofotometría de absorción atómica, mientras que el fósforo (P) y el ácido fítico fueron estimados a través de un método colorimétrico. El γ-oryzanol se cuantificó por HPLC. En general, el contenido de minerales fue mayor en la harina y en el salvado de la variedad Zeta 15. El contenido de P (400,0 ± 5,00 mg/100 g) y Mg (60,0 ± 0,00 mg/100 g) fue menor en la harina de la variedad Cimarrón, mientras que en los salvados de las distintas variedades se observaron valores significativamente altos de P (1860 ± 2,00 - 2185 ± 0,58 mg/100 g) y Ca (66,7 ± 1,15 ­ 73,3 ± 1,53 mg/100 g). Las tres variedades evaluadas representan importantes fuentes de ácido fítico y γ-oryzanol; sin embargo, la variedad Cimarrón fue la que exhibió las menores concentraciones de estos compuestos bioactivos. Basado en los resultados obtenidos, las harinas integrales y los salvados representan una fuente importante de minerales, de ácido fítico y de γ-oryzanol. La concentración de todos los microcomponentes es significativamente superior en los salvados con respecto a las harinas, lo que los convierte en una atractiva alternativa para la obtención de compuestos con actividad biológica de interés para la salud humana(AU)

The objective of this study was to determine the content of some minerals, phytic acid and γ-oryzanol in whole-grain flour and bran in three cultivars (Cimarrón, Fonaiap 1 y Zeta 15) of rice (Oryza sativa L) in Venezuela. The minerals were (Ca, Mg, Fe y Zn) quantified by Atomic Absorption Spectrophotometry while that the phosphorus (P) and phytic acid were determined using a colorimetric method. The γ-oryzanol was quantified by HPLC. In general, the mineral contents were higher in flour than bran in the cultivar Zeta 15. The P (400,0 ± 5,00 mg/100 g) and Mg (60,0 ± 0,00 mg/100 g) contents were lower in flour of the cultivar Cimarrón, while that were observed higher values of P (1860 ± 2,00 - 2185 ± 0,58 mg/100 g) and Ca (66,7 ± 1,15 ­ 73,3 ± 1,53 mg/100 g) in the bran of different cultivars. The three cultivars evaluated are an important source of phytic acid and γ-oryzanol; however, the Cimarrón cultivar exhibited the lowest concentrations of these bioactive compounds. Based on these results, whole-grain flours and brans may offer a good source of minerals, phytic acid and γ-oryzanol. The concentrations of all micro compounds evaluated were higher in the brans than the flours, this become the bran an attractive alternative to obtain compounds with biological activity of interest for human health(AU)

Diversity Analysis of Some Traditional Rice Genotypes in Sri Lanka.

Aims: To study the diversity of traditional rice genotypes in Sri Lanka using cluster analysis and principle component analysis. Study Design: The experiment was carried out using one hundred rice genotypes with six modern rice cultivars and ninety four traditional rice cultivars. Rice genotypes were planted according to a randomized complete block design with four replications and 20 plants per plot with 15 cm X 20 cm spacing. Place and Duration of Study: A field experiment was carried out during 2011/2012 Maha season and 2012 Yala season at Faculty of Agriculture, University of Ruhuna, Sri Lanka. Methodology: Plant height (cm), number of tillers/plant and number of productive tillers/plant were measured before harvesting. Panicle length (cm), panicle weight (g), number of spikelets/panicle, number of fertile spikelets/panicle, 100 grain weight (g) and yield/plant (g) were measured after harvesting and drying of grains for 14% moisture content. Principal component analysis (PCA) and cluster analysis were performed using SPSS statistical software. Results: Among nine studied variables three principal components exhibited more than one Eigen value and showed about 89.6 % variability. The principal components (PC) 1, 2 and 3 had 51.07%, 22.08% and 16.46% variability among the genotypes for the evaluated traits respectively. The first PC was more related to panicle weight, number of spikelets/panicle, number of fertile spikelets/panicle, spikelet fertility percentage and yield (g/plant). Number of tillers/plant, number of productive tillers/plant and yield (g/plant) were more related traits in the second principal component. The highest contribution in third principal component was from the panicle weight, 100 grain weight and yield (g/plant). Based on the nine yield and yield attributing characters, the genotypes were grouped in to seven clusters in cluster analysis. The genotypes under cluster V recorded the highest divergence among them as it exhibited the highest intra-cluster distance. The lowest intracluster distance was recorded in the cluster VI. The modern rice cultivar BG 379/2 was fallen in to the cluster VI with 3 traditional rice cultivars namely Karayal I, Bathkiri el and Hondarawala. Conclusion: One hundred rice genotypes were grouped in to divergent groups by principle component analysis and cluster analysis. This clustering pattern can be used for the selection of parental materials with diverse characters.

Identification of Some Rice Genotypes Resistant to Blast Disease in Egypt.

Blast disease caused by Pyricularia oryzae, is the most important disease of rice in Egypt and in the world. Field surveys in main production regions, revealed that the highest disease incidence was recorded in El-Behera Governorate. Seven rice cultivars were screened for resistance to blast disease. Resistance to disease was studied under both artificially and naturally with local pathogen. A bioassay was developed based on (0-9) scale, Area Under the Disease Progress Curve (AUDPC), disease area and sporulation. Differential expression to pathogen was observed between cultivars. Among seven cultivars, Sakha 101 and Sakha 103 were highly resistant and Giza 175 and Giza 178 were highly susceptible to three strains of fungus P. oryzae. Meanwhile other lines showed moderate resistance and susceptible. At the same time there were great differences concerning the growth rate and yield between different rice cultivars.