Search Results

You are looking at 1 - 6 of 6 items for

  • Author or Editor: L. Ahmad x
Clear All Modify Search

The economic threshold level of Meloidogyne incognita, Alternaria dauci and Rhizoctonia solani were determined on carrot (Daucus carota L.) under greenhouse conditions. The results revealed that plant length, plant fresh weight, shoot and root dry weight, chlorophyll and carotenoid decreased progressively with the corresponding increase in the inoculum levels of each pathogen. The significant reduction in plant growth parameters, chlorophyll and carotenoid occurred when 2000 or more second stage juveniles (J2s) of M. incognita, 1.0 g or more inoculum of A. dauci or R. solani per kg soil were inoculated. Maximum reduction in plant growth attributes, chlorophyll and carotenoid occurred at the highest inoculum level of the test pathogens. Increase in the inoculum level of M. incognita caused an increase in the number of root galls, while the multiplication of nematode was found inversely related to the inoculum density. The increase in the inoculum levels of A. dauci and R. solani resulted in a progressive increase in leaf blight and crown rot indices and caused a higher reduction in plant growth parameters. The damaging threshold level of M. incognita was 2000 J2 per kg soil while 1.0 g per kg soil of A. dauci or R. solani was threshold level on carrot. The assessment of infestation levels of test pathogens will enable growers to cost-effectively select and implement the management tactics.

Restricted access

Effects of Meloidogyne incognita, Alternaria dauci and Fusarium solani were studied on carrot (Daucus carota L.) growth, chlorophyll, carotenoid and proline contents in different types of soil. Plants grown in 20:80 and 40:60% sand:clay soil mixtures showed a significant increase in root dry weight, chlorophyll and carotenoid contents compared to plants grown in 100% clay soil. However, use of 60:40 sand:clay resulted in a similar root dry weight, chlorophyll and carotenoid contents as was found in carrots grown in 100% clay soil. Inoculation of plants with M. incognita, A. dauci or F. solani caused a significant reduction in root dry weight, chlorophyll and carotenoid contents in all soil types as compared to their respective control. Inoculation of plants by A. dauci caused the greatest reduction in root dry weight followed by F. solani and M. incognita in different sand and clay mixtures. Use of 20:80, 40:60 or 60:40 sand:clay mixtures caused a significant increase in proline content of plants over those grown in 100% clay soil. Similarly, inoculation of M. incognita, A. dauci and F. solani caused a significant increase in proline content in all soil types compared to their respective control.

Restricted access

Higher plant population and nitrogen management is an adopted approach for improving crop productivity from limited land resources. Moreover, higher plant density and nitrogen regimes may increase the risk of stalk lodging, which is a consequence of complex interplant competition of individual organs. Here, we aimed to investigate the dynamic change in morphology, chemical compositions and lignin promoting enzymes of the second basal inter-nodes altering lodging risk controlled by planting density and nitrogen levels. A field trial was conducted at the Mengcheng research station (33°9′44″N, 116°32′56″E), Huaibei plain, Anhui province, China. A randomized complete block design was adopted, in which four plant densities, i.e., 180, 240, 300, and 360 × 104 ha−1 and four N levels, i.e., 0, 180, 240, and 300 kg ha−1 were studied. The two popular wheat varieties AnNong0711 and YanNong19 were cultivated. Results revealed that the culm lodging resistance (CLRI) index of the second basal internodes was positively and significantly correlated with light interception, lignin and cellulose content. The lignin and cellulose contents were significantly and positive correlated to light interception. The increased planting density and nitrogen levels declined the lignin and its related enzymes activities. The variety AnNong0711 showed more resistive response to lodging compared to YanNong19. Overall our study found that increased planting densities and nitrogen regimes resulted in poor physical strength and enzymatic activity which enhanced lodging risk in wheat varieties. The current study demonstrated that stem bending strength of the basal internode was significantly positive correlated to grains per spike. The thousand grain weight and grain yield had a positive and significant relationship with stem bending strength of the basal internode. The results suggested that the variety YanNong19 produces higher grain yield (9298 kg ha−1) at density 240 × 104 plants ha−1, and 180 kg ha−1 nitrogen, while AnNong0711 produced higher grain yield (10178.86 kg ha−1) at density 240 × 104 plants ha−1 and with 240 kg ha−1 nitrogen. Moreover, this combination of nitrogen and planting density enhanced the grain yield with better lodging resistance.

Restricted access
Authors: Z. Khan, A. Hussain, M. Ashraf, K. Ahmad, M. Danish and L. McDowell

A study was conducted on the sheep farm of the Livestock Experimental Station, located in the southwestern Punjab, Pakistan, to determine the copper nutrition status of different classes of grazing sheep during two different seasons. A complete free-choice supplement (feed) was available to all animals throughout the year. The purpose of this research was to investigate, as a function of the seasons, the transfer of Cu from soil, and dietary factors to sheep grazing in this semiarid region, in order to evaluate if the Cu requirement of grazing livestock was met or if a deficiency occurred. The final goal was to maximize the production of the animals by adopting, if necessary, adequate, balanced Cu supplementation. Soil, forage, feed and water samples, and animal samples (plasma, milk, faeces and urine from lactating ewes, plasma, faeces and urine from non-lactating ewes and plasma and faeces from male animals) were taken eight times during the year (four times in each season). Soil copper was affected by the seasonal changes and sampling intervals and was significantly higher than plant needs during both seasons, while the forage copper level did not show significant seasonal fluctuations, but was only affected by the sampling intervals. The soil and forage Cu was sufficient for the requirements of the plants and the animals grazing there on during both seasons. The copper contents of the feed and water showed no seasonal or sampling interval fluctuations. The plasma Cu was affected by seasonal variations in non-lactating ewes and in rams and by sampling intervals in the lactating ewes. Faecal and urine Cu was not affected by seasonal or sampling intervals except in non-lactating ewes, where the sampling interval had a pronounced effect on faecal Cu, while milk Cu in lactating ewes was affected by seasonal changes only. In all classes of sheep plasma Cu was higher during the winter than during the summer and remained in the normal range for ruminants during both seasons. It is concluded that a mixture with high bioavailability, containing Cu, should be continuously provided to grazing sheep in this semi-arid region in order to maintain the normal level of Cu and maximize the production potential of ruminants.

Restricted access
Authors: John B. Saunders, Wei Hao, Jiang Long, Daniel L. King, Karl Mann, Mira Fauth-Bühler, Hans-Jürgen Rumpf, Henrietta Bowden-Jones, Afarin Rahimi-Movaghar, Thomas Chung, Elda Chan, Norharlina Bahar, Sophia Achab, Hae Kook Lee, Marc Potenza, Nancy Petry, Daniel Spritzer, Atul Ambekar, Jeffrey Derevensky, Mark D. Griffiths, Halley M. Pontes, Daria Kuss, Susumu Higuchi, Satoko Mihara, Sawitri Assangangkornchai, Manoj Sharma, Ahmad El Kashef, Patrick Ip, Michael Farrell, Emanuele Scafato, Natacha Carragher and Vladimir Poznyak

Online gaming has greatly increased in popularity in recent years, and with this has come a multiplicity of problems due to excessive involvement in gaming. Gaming disorder, both online and offline, has been defined for the first time in the draft of 11th revision of the International Classification of Diseases (ICD-11). National surveys have shown prevalence rates of gaming disorder/addiction of 10%–15% among young people in several Asian countries and of 1%–10% in their counterparts in some Western countries. Several diseases related to excessive gaming are now recognized, and clinics are being established to respond to individual, family, and community concerns, but many cases remain hidden. Gaming disorder shares many features with addictions due to psychoactive substances and with gambling disorder, and functional neuroimaging shows that similar areas of the brain are activated. Governments and health agencies worldwide are seeking for the effects of online gaming to be addressed, and for preventive approaches to be developed. Central to this effort is a need to delineate the nature of the problem, which is the purpose of the definitions in the draft of ICD-11.

Open access

Including gaming disorder in the ICD-11: The need to do so from a clinical and public health perspective

Commentary on: A weak scientific basis for gaming disorder: Let us err on the side of caution (van Rooij et al., 2018)

Authors: Hans-Jürgen Rumpf, Sophia Achab, Joël Billieux, Henrietta Bowden-Jones, Natacha Carragher, Zsolt Demetrovics, Susumu Higuchi, Daniel L. King, Karl Mann, Marc Potenza, John B. Saunders, Max Abbott, Atul Ambekar, Osman Tolga Aricak, Sawitri Assanangkornchai, Norharlina Bahar, Guilherme Borges, Matthias Brand, Elda Mei-Lo Chan, Thomas Chung, Jeff Derevensky, Ahmad El Kashef, Michael Farrell, Naomi A. Fineberg, Claudia Gandin, Douglas A. Gentile, Mark D. Griffiths, Anna E. Goudriaan, Marie Grall-Bronnec, Wei Hao, David C. Hodgins, Patrick Ip, Orsolya Király, Hae Kook Lee, Daria Kuss, Jeroen S. Lemmens, Jiang Long, Olatz Lopez-Fernandez, Satoko Mihara, Nancy M. Petry, Halley M. Pontes, Afarin Rahimi-Movaghar, Florian Rehbein, Jürgen Rehm, Emanuele Scafato, Manoi Sharma, Daniel Spritzer, Dan J. Stein, Philip Tam, Aviv Weinstein, Hans-Ulrich Wittchen, Klaus Wölfling, Daniele Zullino and Vladimir Poznyak

The proposed introduction of gaming disorder (GD) in the 11th revision of the International Classification of Diseases (ICD-11) developed by the World Health Organization (WHO) has led to a lively debate over the past year. Besides the broad support for the decision in the academic press, a recent publication by van Rooij et al. (2018) repeated the criticism raised against the inclusion of GD in ICD-11 by Aarseth et al. (2017). We argue that this group of researchers fails to recognize the clinical and public health considerations, which support the WHO perspective. It is important to recognize a range of biases that may influence this debate; in particular, the gaming industry may wish to diminish its responsibility by claiming that GD is not a public health problem, a position which maybe supported by arguments from scholars based in media psychology, computer games research, communication science, and related disciplines. However, just as with any other disease or disorder in the ICD-11, the decision whether or not to include GD is based on clinical evidence and public health needs. Therefore, we reiterate our conclusion that including GD reflects the essence of the ICD and will facilitate treatment and prevention for those who need it.

Open access