98 research outputs found

    Herbicide Evaluation in Arkansas Rice, 1997

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    Weed control is economically important for production of rice, a major crop in Arkansas. These findings summarize efforts of the team of Arkansas scientists working on weed control strategies for rice during 1997. Various technologies were evaluated in field studies at five locations involving the major weed problems and rice production systems used in the state. Results from these studies will add to the arsenal of weed control options for producers. Highlights include synergists and safeners for herbicides to aid in control of propanil-resistant barnyardgrass; herbicides and flooding techniques for control of red rice and other weeds; and the use of transgenic rice cultivars for broadspectrum weed control. The preliminary results reported here generally warrant further testing for more advanced findings and for the labeling of new technologies, and finally are the basis for updating safe, effective, and economical recommendations to Arkansas rice producers

    Herbicide Evaluation in Arkansas Rice 2000

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    With the widespread development of resistance to propanil by barnyardgrass, the major weed in rice, research has been intensified in recent years to develop alternative weed control technology to the repeated use of propanil. The use of herbicides is economically important for production of rice. Field experiments are conducted annually in Arkansas to evaluate the activity of developmental and commercial herbicides for selective control of barnyardgrass and other weeds in rice. These experiments serve both industry and Arkansas agriculture by providing information on the selectivity of herbicides still in the developmental stage and by comparing the activity of these new herbicides with that of recommended herbicides

    Herbicide Evaluation in Arkansas Rice, 1998

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    Weed control is economically important for production of rice, a major crop in Arkansas. These findings summarize efforts of the team of Arkansas scientists working on weed control strategies for rice during 1998. Various technologies were evaluated in field studies involving the major weed problems and rice production systems used in the state. Results from these studies will add to the arsenal of weed control options for producers. The preliminary results reported here generally warrant further testing for more advanced findings and for the labeling of new technologies and, finally, are the basis for updating safe, effective, and economical recommendations to Arkansas rice producers

    Recent and Projected Increases in Atmospheric CO2 Concentration Can Enhance Gene Flow between Wild and Genetically Altered Rice (Oryza sativa)

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    Although recent and projected increases in atmospheric carbon dioxide can alter plant phenological development, these changes have not been quantified in terms of floral outcrossing rates or gene transfer. Could differential phenological development in response to rising CO2 between genetically modified crops and wild, weedy relatives increase the spread of novel genes, potentially altering evolutionary fitness? Here we show that increasing CO2 from an early 20th century concentration (300 µmol mol−1) to current (400 µmol mol−1) and projected, mid-21st century (600 µmol mol−1) values, enhanced the flow of genes from wild, weedy rice to the genetically altered, herbicide resistant, cultivated population, with outcrossing increasing from 0.22% to 0.71% from 300 to 600 µmol mol−1. The increase in outcrossing and gene transfer was associated with differential increases in plant height, as well as greater tiller and panicle production in the wild, relative to the cultivated population. In addition, increasing CO2 also resulted in a greater synchronicity in flowering times between the two populations. The observed changes reported here resulted in a subsequent increase in rice dedomestication and a greater number of weedy, herbicide-resistant hybrid progeny. Overall, these data suggest that differential phenological responses to rising atmospheric CO2 could result in enhanced flow of novel genes and greater success of feral plant species in agroecosystems

    Molecular Evolution of the Rice Blast Resistance Gene Pi-ta in Invasive Weedy Rice in the USA

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    The Pi-ta gene in rice has been effectively used to control rice blast disease caused by Magnaporthe oryzae worldwide. Despite a number of studies that reported the Pi-ta gene in domesticated rice and wild species, little is known about how the Pi-ta gene has evolved in US weedy rice, a major weed of rice. To investigate the genome organization of the Pi-ta gene in weedy rice and its relationship to gene flow between cultivated and weedy rice in the US, we analyzed nucleotide sequence variation at the Pi-ta gene and its surrounding 2 Mb region in 156 weedy, domesticated and wild rice relatives. We found that the region at and around the Pi-ta gene shows very low genetic diversity in US weedy rice. The patterns of molecular diversity in weeds are more similar to cultivated rice (indica and aus), which have never been cultivated in the US, rather than the wild rice species, Oryza rufipogon. In addition, the resistant Pi-ta allele (Pi-ta) found in the majority of US weedy rice belongs to the weedy group strawhull awnless (SH), suggesting a single source of origin for Pi-ta. Weeds with Pi-ta were resistant to two M. oryzae races, IC17 and IB49, except for three accessions, suggesting that component(s) required for the Pi-ta mediated resistance may be missing in these accessions. Signatures of flanking sequences of the Pi-ta gene and SSR markers on chromosome 12 suggest that the susceptible pi-ta allele (pi-ta), not Pi-ta, has been introgressed from cultivated to weedy rice by out-crossing

    Hubungan Kandidiasis Intertriginosa dan Diabetes Melitus Tipe 2 di Poliklinik Kulit dan Kelamin RSUD Dokter Soedarso Pontianak pada Tahun 2012

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    Background. Intertriginous candidiasis is a type of cutaneous candidiasiswhich is located at the axila, inguinal, intergluteal, inframammary,interdigitalis, glands penis, and umbilicus. One of the risk factors ofintertriginous candidiasis patient is people with diabetes mellitus (DM).The increase of glucose concentration makes more susceptible frominfection. Objective. Define the association between intertriginouscandidiasis and DM type 2. Method. This research was a case controlstudy which took place in Dermatovenereology Outpatient Clinic RSUD dr.Soedarso from June until November 2013. The minimum sample for thisresearch was 126 people and divided into two groups. The case groupconsisted of 63 people and the control group consisted of 63 people. Thesubjects were selected by using consecutive sampling and analyzed bychi-square test. Result. There was an association between intertriginouscandidiasis with DM type 2 (p= 0,01). Odds Ratio (OR) value of thisresearch was 2,621 (IK 95% : 1,246 5,516). Conclusion. Intertriginouscandidiasis is associated with DM type 2 and people with DM type 2 havea possibility of 2,621 times higher risk of acquiring intertriginouscandidiasis than people without diabetes mellitus
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