Effects of Ufra Disease on Yield Loss of Deepwater Rice in Bangladesh     

P. G. Cox  L. Rahman 《国际虫害防治杂志》2013,59(4):410-415

Abstract

Ufra, caused by the stem nematode, Ditylenchus angustus (Butler, 1913) Filipjev, 1936, is a serious disease of deepwater rice in southern Bangladesh. It was studied between 1977 and 1979 as part of a joint project with the Overseas Development Administration at the Bangladesh Rice Research Institute. Three symptom types are distinguished according to the extent of panicle emergence: Ufra1 (none), Ufra2 (partial) and Ufra3 (complete). All three represent total loss from that panicle. The number of Ufra2 as a percentage of the total number of panicles present in a specified area is selected as a disease index (UfraII). A function relating yield to the level of UfraII is proposed on the basis of selective samples from a field with a well-defined ufra patch. This function is compared with another derived from random samples in different fields along a linear transect through an area where ufra is endemic. Loss of panicle density, i.e. panicles/m², is identified as a major component of yield loss, approximately equal to the loss associated with all three symptom types added together. Although severe and widely distributed throughout the southern part of the deepwater rice region in 1977 and 1978, it was very difficult to find in 1979 when there was a spring drought. Ufra is worse in wet years, in areas which flood early, and where the crop is harvested late. The length of the over-winter decay phase appears to be a critical factor regulating the survival of the pathogen from one season to the next. This suggests an approach for ufra control.  相似文献   

Co‐infection by Botryosphaeriaceae and Ilyonectria spp. fungi during propagation causes decline of young grafted grapevines     

M. A. Whitelaw‐Weckert  L. Rahman  L. M. Appleby  A. Hall  A. C. Clark  H. Waite  W. J. Hardie 《Plant pathology》2013,62(6):1226-1237

Decline of newly planted, grafted grapevines is a serious viticultural problem worldwide. In the Riverina (New South Wales, Australia), characteristic symptoms include low fruit yields, very short shoots and severely stunted roots with black, sunken, necrotic lesions. To determine the cause, roots and wood tissue from affected plants in 20 vineyards (Vitis vinifera cv. Chardonnay grafted to V. champini cv. Ramsey rootstock) were assayed for microbial pathogens. Ilyonectria spp. (I. macrodidyma or I. liriodendra, producers of phytotoxin brefeldin A, BFA, and cause of black foot disease of grapevines) and Botryosphaeriaceae spp. (predominantly Diplodia seriata) were isolated from rootstocks of 100 and 95% of the plants, respectively. Togninia minima and Phaeomoniella chlamydospora (cause of grapevine Petri disease) were isolated from 13 and 7% of affected plants, respectively. All Ramsey rootstock stems of grafted plants sampled from a supplier nursery were infected with Ilyonectria spp. and D. seriata. Diplodia seriata, but not Ilyonectria spp., was also isolated from 25% of canes sampled from the rootstock source block. Root inoculation of potted, disease‐free Chardonnay plants with Ilyonectria isolates from diseased vineyards caused typical disease symptoms, while co‐inoculation with Botryosphaeriaceae spp. increased disease severity. This is the first study to show that a major cause of young grapevine decline can be sequential infection by Botryosphaeriaceae from rootstock cuttings and Ilyonectria spp. from nursery soil. Although the Petri disease fungi were less common in young declining grafted grapevines in the Riverina, they are likely to contribute to the decline of surviving plants as they mature.  相似文献   

Comparison of changes in sugars and ethylene production of cherimoya fruit grown at different seasons     

Keiichi Nomura  H. Terai  K. Yabe  M. Maeda  M. S. M. Rahman  M. Yoshida 《The Journal of Horticultural Science and Biotechnology》2013,88(4):617-622

Summary

Changes in fruit weight, total soluble solids (TSS), sugar content and postharvest ethylene production during fruit development were compared on fruit of cherimoya (Annona cherimola Mill., cv. Big Sister) pollinated at different times (early, at the beginning of April, 1995 and late, at the end of May, 1994). Fruit weight increased by growth, independently of pollination times. Changes in TSS and sugar content were strongly affected by pollination time. In late pollinated fruits, both TSS and sugar content increased during the growth period, 110–160 d after pollination, while neither increased with fruit growth in early pollinated fruit. Moreover, changes in TSS and sugar content after ripening depended not only on pollination time but also on the growth period. With late pollination, fruit harvested after 140 d became edible after ripening. The TSS and total sugar contents, (the sum of fructose, glucose and sucrose contents) increased to about 20° Brix and above 16%, respectively. But early pollinated fruits were not edible after ripening, since total sugar content increased only to about 7%, even though they kept growing for 160 d on the tree. The maximum rate of ethylene production declined and the number of days to the ethylene peak from harvest is also reduced with growth in both cases. These changes were closely correlated with days after pollination (r>0.9) regardless of pollination time. Comparisons of accumulated temperature suggest that temperature at pollination time and during the resting period of growth affected fruit development. These results indicate that neither fruit weight nor number of days after pollination is a suitable index for harvesting time.  相似文献   

Papaya (Carica papaya L.) Leaf Powder: Novel Adsorbent for Removal of Methylene Blue from Aqueous Solution     

M. Zobayer Bin Mukhlish  Maksudur Rahman Khan  Mithun Chandra Bhoumick  Sumona Paul 《Water, air, and soil pollution》2012,223(8):4949-4958

Batch sorption experiments were carried out to investigate the potentiality of papaya leaf powder (PLP) for the removal of methylene blue (MB) from aqueous solution. The effects of various experimental parameters, such as adsorbent dose, initial solution concentration, contact time, and solution pH were also studied. The amount of dye adsorbed was found to increase with increase in initial dye concentrations. Papaya leaf adsorbs MB better in basic medium. The adsorption equilibrium data fitted well in the Langmuir isotherm equation with a monolayer sorption capacity of 512.55?mg?g^?1. The kinetics of MB adsorption onto papaya leaf was examined using the pseudo-first and pseudo-second order and unified approach kinetic models. The adsorption kinetics followed the pseudo-second order kinetic model, but the rate constant was found to depend on initial dye concentration. The unified approach model described the equilibrium and kinetics well. The forward and backward rate constants were determined from the unified approach model.  相似文献   

Organoclays reduce arsenic bioavailability and bioaccessibility in contaminated soils     

Binoy Sarkar  Ravi Naidu  Mohammad Mahmudur Rahman  Mallavarapu Megharaj  Yunfei Xi 《Journal of Soils and Sediments》2012,12(5):704-712

Purpose  

Naturally occurring layer silicate clay minerals can be value added by modifying their surface properties to enhance their efficacy in the remediation of environmental contaminants. Silicate clay minerals modified by the introduction of organic molecules into the mineral structure are known as organoclays and show much promise for environmental remediation applications. The present study assesses the extent of decrease in bioavailable and bioaccessible arsenic (As) via enhanced adsorption by soil treated with organoclays.  相似文献   

Evaluation of the antigen relatedness and efficacy of a single vaccination with different infectious bronchitis virus strains against a challenge with Malaysian variant and QX-like IBV strains     

Mohd Iswadi Ismail  Sheau Wei Tan  Mohd Hair-Bejo  Abdul Rahman Omar 《Journal of veterinary science (Suw?n-si, Korea)》2020,21(6)

BackgroundThe predominant infectious bronchitis virus (IBV) strains detected in chickens in Malaysia are the Malaysian variant (MV) and QX-like, which are associated with respiratory distress, nephropathy, and high mortality. On the other hand, the antigenic relatedness and efficacy of IBV vaccines against these 2 field IBV strains are not well characterized.ObjectivesThis study aimed to determine the antigen relatedness and efficacy of different IB vaccine strains against a challenge with MV and QX-like strains.MethodsThe antigen relatedness and the ability of different IB vaccine strains in conferring protection against MV and QX-like were assessed based on the clinical signs, macroscopic lesions, and ciliary activity.ResultsThe MV strain IBS037A/2014 showed minor antigenic subtype differences with the vaccine virus Mass H120 and 4/91 strains but showed major antigenic subtype differences with the K2 strain. The Malaysian QX-like strain IBS130/2015 showed major antigenic subtype differences with the MV strain IBS037A/2014 and the vaccine strains except for K2. Chickens vaccinated once with Mass (H120) or with non-Mass (4/91 and K2) developed antibody responses with the highest antibody titer detected in the groups vaccinated with H120 and 4/91. The mean ciliary activities of the vaccinated chickens were between 56 to 59% and 48 to 52% in chickens challenged with IBS037A/2014 and IBS130/2015, respectively. The vaccinated and challenged birds showed mild to severe lesions in the lungs and kidneys.ConclusionsDespite the minor antigenic subtype differences, a single inoculation with Mass or non-Mass vaccines could not protect against the MV IBS037A/2014 and QX-like IBS130/2015.  相似文献   

Production analysis of broiler farming in central Punjab,Pakistan     

Rahman  Naeem Ur  Mehmood  Shahid  Ahmad  Sohail  Javid  Arshad  Mahmud  Athar  Hussain  Jibran  Shaheen  Muhammad Shabir  Usman  Muhammad  Mohayud Din Hashmi  Syed Ghulam 《Tropical animal health and production》2020,52(3):1125-1131

Tropical Animal Health and Production - This study examined the analysis of personal and production performance of broiler farming in 10 cities of central Punjab (Lahore, Sheikhupura, Kasur, Okara,...  相似文献   

AGRONOMIC EFFICIENCY AND PROFITABILITY OF P-FERTILIZERS APPLIED AT DIFFERENT PLANTING DENSITIES OF MAIZE IN NORTHWEST PAKISTAN     

Amanullah  Muhammad Asif  Lal K. Almas  Amanullah Jan  Zahir Shah  Hidayat ur Rahman 《Journal of plant nutrition》2013,36(3):331-341

The use of appropriate source of phosphorus (P) fertilizer at different planting densities has considerable impact on growth, grain yield as well as profitability of maize (Zea mays L). Field experiment was conducted in order to investigate the impact of P sources [(S₀ = P not applied, S₁ = SSP (single super phosphate) S₂ = NP (nitrophos), and S₃ = DAP (diammonium phosphate)] on maize growth analysis, yield and economic returns planted at different planting densities (D₁ = 40,000, D₂ = 60,000, D₃ = 80,000, and D₄ = 100,000 plants ha^?1) at the New Developmental Agricultural Research Farm of Khyber Pakhtunkhwa Agricultural University, Peshawar, Pakistan, during summer 2006. This paper reports the profitability data with two objectives: 1) to compare agronomic efficiency and profitability of P-fertilizers, and 2) to know whether plant densities affect agronomic efficiency and profitability of P-fertilizers. Application of DAP and SSP resulted in higher partial factor productivity (PFP) (63.58 and 61.92 kg grains kg^?1 P), agronomic efficiency (AE) (13.01 and 13.71 kg grains kg^?1 P) and net returns (NR) (Rs. 16,289 and 16,204 ha^?1), respectively, while NP stood at the bottom in the ranking with lower PFP (57.16 kg grains kg^?1 P), AE (8.94 kg grains kg^?1 P) and NR (Rs. 4,472 ha^?1). Among the plant densities, D₃ stood first with maximum PFP (69.60 kg grains kg^?1 P), AE (18.21 kg grains kg^?1 P) and NR (Rs. 21,461 ha^?1) as compared to other plant densities. In conclusion, the findings suggest that growing maize at D₃ applied with either SSP or DAP is more profitable in the wheat-maize cropping system in the study area.  相似文献   

Alleviation of manganese toxicity and manganese-induced iron deficiency in barley by additional potassium supply in nutrient solution     

Shah Alam  Muhammad Hasinur Rahman  Shigeru Kamei  Shigenao Kawai 《Soil Science and Plant Nutrition》2013,59(3):387-392

Barley plants were grown hydroponically at two levels of K (3.0 and 30 mm) and Fe (1.0 and 10 μm) in the presence of excess Mn (25 μm) for 14 d in a phytotron. Plants grown under adequate K level (3.0 mm) were characterized by brown spots on old leaves, desiccation of old leaves, interveinal chlorosis on young leaves, browning of roots, and release of phytosiderophores (PS) from roots. These symptoms were more pronounced in the plants grown under suboptimal Fe level (1.0 p,M) than in the plants grown under adequate Fe level (10 μm). Plants grown in 10 μm Fe with additional K (30 mm) produced a larger amount of dry matter and released less PS than the plants grown under adequate K level (3.0 mm), and did not show leaf injury symptoms and root browning. On the other hand, the additional K supply in the presence of 1.0 μM Fe decreased the severity of brown spots, prevented leaf desiccation, and increased the leaf chlorophyll content, which was not sufficient for the regreening of chlorotic leaves. These results suggested that the additional K alleviated the symptoms of Mn toxicity depending on the Fe concentration in the nutrient solution. The concentration (per g dry matter) and accumulation (per plant) of Mn in shoots and roots of plants grown in 10 μm Fe and 30 mm K were much lower than those of the plants grown in 10 μm Fe and 3.0 mm K, indicating that additional K repressed the absorption of Mn. The concentration and accumulation of Fe in the shoots and roots of the plants grown in 10 μm Fe and 30 mm K were higher than those of the plants grown in 10 μm Fe and 3.0 mm K, indicating that the additional K increased the absorption of Fe under excess Mn level in the nutrient solution. The release of PS, chlorophyll content, and shoot Fe concentration were closely correlated.  相似文献   

Effect of Extraction Variables on the Biodegradable Chelant-Assisted Removal of Toxic Metals from Artificially Contaminated European Reference Soils     

Zinnat A. Begum  Ismail M. M. Rahman  Hikaru Sawai  Satoshi Mizutani  Teruya Maki  Hiroshi Hasegawa 《Water, air, and soil pollution》2013,224(3):1-21

Development of aminopolycarboxylate chelants (APCs) having enhanced biodegradability is gaining increasing focus to replace the EDTA and its homologs with those used widely for the ex situ treatment of contaminated soils and are potential eco-threats. The paper reports the chelant-assisted extraction of the toxic metals (Cd, Cu, Pb, and Zn) from the metal-spiked European reference soils (Eurosoil 1 and Eurosoil 4) using biodegradable APCs, namely EDDS, GLDA, and HIDS. The effects of chelant-to-metal molar ratio, solution pH, and metal/chelant stability constants were evaluated, and compared with that of EDTA. The selectivity aptitude of the biodegradable chelants towards the toxic metals was assumed from the speciation calculations, and a proportionate correlation was observed at neutral pH. Pre- and post-extractive solid phase distributions of the target metals were defined using the sequential extraction procedure and dissolution of metals from the theoretically immobilized fraction was witnessed. The effect of competing species (Al, Ca, Fe, Mg, and Mn) concentrations was proven to be minimized with an excess of chelant in solution. The highlight of the outcomes is the superior decontamination ability of GLDA, a biodegradable APC, at minimum chelant concentration in solution and applicability at a wide range of pH environments.  相似文献