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Ozberk I.,Harran University | Yolcu S.,Extension Service | Yucel A.,Harran University | Koten M.,Harran University | Nicol J.M.,Plant Pathology
African Journal of Agricultural Research | Year: 2011

The objective of this study was to draw the attention for this under estimated pest in the South-east of Anatolia. Field studies were carried out in historically known infested farmer fields to assess the effects of seed gall nematode (Anguina tritici [Steinbuch]) on grain yield, quality and marketing price of durum wheat (Triticum durum Desf.) in the wheat production region of Viransehir, Anatolia, Turkey during 2008/2009 growing season. Grain yield losses due to A. tritici were reported up to 32%. Seed gall severity corresponded with a decrease in number of grain spike -1, grain weight spike-1, test weight (kg hl -1) and 1000 kernel weight (g). However, the SDS protein content (%) was not affected by increase in seed galls. The price of durum wheat per tonne was reduced from 335 to 297 USD$ with increasing A. tritici contamination (from 5 to 20%). This could be explained by a significant negative regression with grain price against A. tritici (P ≤ 0.01; R 2 = 80.2%). A. tritici has a potential to be one of the major biotic constraints in the irrigated wheat production regions of Anatolia as both yield and grain price were affected. The use of clean seeds should assist in effective control and careful monitoring is a must. © 2011 Academic Journals.

Yenjerappa S.T.,University of Agricultural Sciences, Dharwad | Rafee C.M.,Agricultural Entomology | Nargund V.B.,Plant Pathology
Acta Horticulturae | Year: 2011

Bacterial blight of pomegranate caused by Xanthomonas axonopodis pv. punicae is a serious threat for production in all the pomegranate growing regions of northern Karnataka. Efforts were made to screen the commercially available bactericides, bio-agents and botanicals for their efficacy against the disease. Trials were conducted for two years during 2002-2003 and 2003-2004 in a farmer's field at Sanjeevarayanakote village of Bellary taluk. The experiment was set up in randomized block design with three replications. There were eight treatments comprising bactericides, bio-gents and botanicals. Bactericides were sprayed in combination with copper oxychloride. A total of five sprays were given at an interval of 15 days with first spray at the disease onset. Studies on performance of different treatments over two years experimentation revealed a lowest disease index of 22.3% in streptocycline (0.05%) + copper oxychloride (0.2%) treated plots followed by bacterinol 100 (0.05%) + copper oxychloride (0.2%) and bacteriomycin (0.05%) + copper oxychloride (0.2%), which recorded 27.2% disease index. All these three bactericides exhibited efficacy on par with each other and significantly superior efficacy over Pseudomonas fluorescens at 0.5% (bioagent) and garlic extract at 2% (botanical). The highest disease severity of 63.1% was recorded in the untreated check plot.

Gupta R.C.,Plant Pathology | Yadav S.P.,Organic Chemist | Gupta R.P.,National Horticultural Research and Development Foundation
Pestology | Year: 2013

The study was conducted at Research Farm, National Horticultural Research and Development Foundation, Nashik to evaluate the efficacy of commonly recommended pesticides against important foliar diseases of onion. Results revealed that significantly lowest incidence (30%) and intensity (5%) of stemphylium blight was recorded in sprays of mancozeb @ 0.25% at 15 days intervals and mancozeb @ 0.25% at 30 days intervals before harvesting. The highest disease incidence (40%) and intensity (9%) of stemphylium blight was recorded in untreated control. Further, it is evident from the data that significantly highest gross yield (340 q/ha) and marketable yield (326 q/ha) was also recorded in mancozeb @ 0.25% sprayed at 15 days interval. Thrips were effectively managed by systemic insecticides namely deltamethrin @ 0.1% and fipronil @ 0.15% spayed at 15 days intervals. Onion bulbs were analyzed for pesticide residue at our Pesticide Residue Laboratory accredited by NABL. The residue analysis report shows that no residues of all the three pesticides namely mancozeb, deltamethrin and fipronil were detected in onion bulbs received from all treatments after harvest.

News Article
Site: phys.org

UC Davis geneticists David Neale and Charles Langley worked with the California Walnut Board to develop genetic markers for use with classical walnut breeding. The first step was to sequence the walnut genome, which, unlike most major agricultural crops, had never been sequenced. This represents the first reference genome sequence for a nut crop. UC Davis has the only walnut breeding program in California. The Walnut Improvement Program, under the direction of plant breeder Chuck Leslie, cooperates with a large number of research partners to develop new walnut varieties. The walnut variety Chandler was used for the sequencing project because it is the leading variety of walnut in California. It is grown on about 50 percent of California's walnut acreage and accounts for more than 70 percent of the trees sold for new plantings. California produces 99 percent of U.S. commercial walnuts, and walnuts are the state's fourth-largest agricultural export. Consumer demand for nuts is growing, and nutritionists are touting the health attributes of moderate nut consumption in lowering the risk for heart disease. Walnuts are high in omega-3 fatty acids, a healthy form of fatty acids, and can be part of a heart-healthy diet by lowering low-density lipoprotein, or LDL, cholesterol levels in blood. Growers are also striving to produce nuts more sustainably, particularly in the areas of pest management and drought tolerance. Commercial walnut trees are grafted onto rootstocks, usually a California native black walnut species or a hybrid, known to better withstand diseases, pests and abiotic stress. For the scion, or nut-bearing portion of the tree, an English walnut species is usually used, and breeders are interested in yield, nut quality, harvest date and meeting consumer preferences. Having the genome sequence of the walnut should accelerate its rate of breeding and variety improvement. Dan Kluepfel, a USDA research plant pathologist in the UC Davis Department of Plant Pathology, is heading a project to breed for walnut rootstock disease resistance. The information will help breeders select for desired traits such as insect and disease resistance and drought tolerance. In addition to the completed genome sequencing of the Chandler walnut variety, Neale and Langley are sequencing the walnut rootstock species. This composite information will provide additional genomic resources that can be combined with traditional breeding techniques to develop new walnut varieties. Chandler walnuts, for example, are harvested late in the season, and growers would like earlier harvests. Marker-assisted breeding provides an opportunity to develop early harvesting cultivars with the desirable attributes of Chandler. "The large repository of walnut genetic material at UC Davis along with new genomic resources lay the groundwork for future breeding of more-sustainable walnut varieties that meet the growing demand for walnuts," said Neale. UC Davis and the California Walnut Board, which funded the project, have made the walnut genome sequencing information publicly available. Explore further: Walnut trees may not be able to withstand climate change

News Article
Site: phys.org

The recently released iPhone/iPad and Android app, PMapp, will help grapegrowers and wineries make informed decisions about the quality and price of grapes. The development of PMapp has been supported by Wine Australia as part of a wider research project seeking to establish objective measures for quantifying powdery mildew. The app development has taken place in close consultation with a project reference group of viticulturists, wineries, independent assessors and researchers. "Powdery mildew is a serious disease of grapevines worldwide and, in Australia, has an estimated annual cost of $76 million through yield loss and the cost of control," says project leader Professor Eileen Scott, Professor of Plant Pathology in the University's School of Agriculture, Food and Wine. "It causes serious quality issues with bad flavours and aromas in wine and we've seen that with small amounts of the surface area of Chardonnay bunches affected by powdery mildew there is an oily 'mouth-feel' in the resulting wine. "The wine sector therefore has a very low tolerance of powdery mildew on grapes with downgrading at 3–6% or rejection when disease is more severe. This is a costly disease for the grape and wine community. "But powdery mildew is hard to assess – the disease is ubiquitous, but symptoms can be hard to see, or easily confused with dust or spray residue. "PMapp is a simple tool that facilitates efficient assessment and recording of the severity and incidence of powdery mildew in the vineyard." Dr Liz Waters, Wine Australia Research Development and Extension Portfolio Manager, says tools such as PMapp help support decision making to build grape and wine excellence in the Australian sector. "The ultimate aim of research and development in this area is to develop objective analytical methods to assess powdery mildew infection levels. Although visual assessment is subjective, this new app will facilitate these assessments and enable efficient and cost-effective vineyard practices," says Dr Waters. PMapp allows the user to quickly assess visually the severity of powdery mildew on each bunch of grapes (an estimation of the percentage of the surface area of the bunch covered) by matching it with a computer generated image. The app calculates the proportion of bunches affected (the disease incidence) and of surface area affected (severity) and reports the data in a spreadsheet for subsequent analysis. A key reference and browser of images built into the app also help the user familiarise themselves with various disease patterns and severities. A website to support the app is currently being developed and is scheduled for release at the end of January. The PMapp is now available on Apple's App Store or Google Play.

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