Expert system is the computer system that solves a domain specific real-world problem using human knowledge and reasoning expertise. Knowledge and inference are the two important parts of an ES. In the development of disease diagnostic ES, knowledge engineering and its maintenance is a big challenge as knowledge involved is of dynamic nature. The classification scheme of concepts of disease symptoms is an important issue in the design of entities or objects dealing with disease knowledge. In this work, the complete process of knowledge acquisition and engineering for disease management of crops has been standardized and a new prototype of web-based knowledge management system (KMS) has been developed. The different components of KMS include efficient tools for knowledge acquisition, storing, knowledge engineering, processing of knowledge, management of knowledge, associated reasoning services and a new interface to define, manipulate and query for disease diagnostic knowledge. The current paper discusses the adopted development methodology and the experience acquired during knowledge engineering and the development of web-based KMS for crop diseases.

A tractor-drawn broad bed furrow (BBF) seed drill machine for soybean [Glycine max (L.) Merrill] was conceived, fabricated and farm validated. It effectively operates in Vertisols and associated soils and is attachable to the tractor for facilitating formation of broad bed along with furrows on both the sides of the beds of desired width and depths and subsequent sowing in one go. Plant population mortality in soybean with tractor-drawn BBF seed drill for Vertisols was reduced in the range of 14-19% as compared to flat bed under the vagaries of monsoon which subsequently resulted in yield enhancement to the extent of 18.65%. Study also indicated that tractor-operated BBF seed drill specifically fabricated for individual tractor performed better in Vertisols and under prevailing field draft conditions.

The study undertaken to assess the genetic changes on yield, agronomic traits and foliar diseases during the last 39 years (1969 to 2008), revealed 103.5 % yield improvement over the years @ 2.6 % per year. The annual genetic gain in seed yield of soybean varieties released in India during this period was approximately 23 kg ha(-1). This yield increase was assigned to increase in number of pods and seeds per plant. Seeds per plant increased by 1.56% per year. Foliar diseases decreased consistently over the period. Varieties namely Kalitur, Bragg, Punjab 1, PK 308, PK 471, JS 71-05, NRC 2, PS 1042, JS 93-05 and PS 1347 were stable over the seasons for the yield. Varieties namely Kalitur, Bragg, Punjab 1 and PS 1042 were found suitable in unfavorable seasons while varieties viz., PK 308, PK 471, JS 71-05, NRC 2, JS 93-05 and PS 1347 were found suitable in favorable seasons. None of the varieties was found consistently superior for all the characters in all the seasons.

The objective of this project was to compile estimates of yield loss in soybean [Glycine max (L.) Merr] to diseases in the top eight soybean-producing countries in 2006. The purpose was to provide information needed by local and world agencies to allocate funds for research and to help scientists focus and coordinate research efforts. Methods used by plant pathologists to estimate yield loss to diseases in these countries included systematic field surveys, cultivar trials, diagnostic clinic records, personal observations, and questionnaires sent to crop consultants and extension staff. The 2006 harvest of soybeans in the top eight soybean-producing countries was reduced an estimated 59.9 million metric tonnes (t) by diseases according to results of the current study. Soybean rust, caused by Phakopsora pachyrhizi, reduced yield in all these countries except Canada in 2006, and the total was more than any other. Next in decreasing order of total yield loss were soybean cyst nematode, brown spot, seedling diseases, anthracnose, and charcoal rot. Accepted for publication 27 October 2009. Published 25 January 2010.

This paper presents a knowledge management system for crop disease. The aim of KMSCD is to provide a knowledge management tool for efficient knowledge acquisition, storage, knowledge engineering, processing and proper maintenance of knowledge that can be ultimately used by the diagnostic expert system. The development of the KMSCD simplifies the complete process of knowledge management by providing user-friendly interface to the domain expert for entering and storing the domain specific knowledge to solve the disease identification and control problem particularly for oilseeds crops. The system presently applies to the knowledge management of 25 prevalent diseases of three major oilseeds crops of India viz, soybean, groundnut and rapeseed mustard. The adopted development methodology and the experience acquired in the knowledge engineering and development of knowledge management system for crop disease are discussed in this paper.

Soybean (Glycine max (L.) Merrill) is susceptible to the fungal pathogen, Sclerotium rolfsii from seedling emergence to pod fill. A few systemic and non-systemic fungicides have been recommended as pre-sowing seed treatment (ST) for the management of Sclerotium blight of soybean worldwide. But farmers, especially in developing countries do not utilize ST mainly on account of preoccupation in other practices considered by them essential for sowing. The possibility of ST applied well in advance of sowing was therefore investigated. Results indicated that ST on average increased field emergence by 26.19%, reduced post-emergence mortality (POM) by 49.03% and enhanced seed yield by 23.00%. Seed treatment with carboxin 37.5%+thiram 37.5% @ 0.2% was the best. Seed treatment 50days prior to sowing was superior by increasing emergence, reducing POM and enhancing seed yield with high monetary returns and energy output.

The experiments on research farm and farmers' field were conducted at NRC for Soybean, Indore and in nearby villages during 2003-04 to 2005-06 to assess the impact of balanced fertilization particularly of potassium nutrition on productivity of soybean as well as soybean-wheat cropping system under NRCS-IPI Project. Potassium application had significant positive effect on growth and nodulation in soybean. It favourably influenced the quality parameters of soybean as well. There was significant reduction in insect-pests infestation and disease incidence in soybean receiving potassium dressings. Application of 25 kg basal + 25 kg K 2O/ha at flowering (R 2 stage) gave maximum productivity of soybean-wheat cropping system while application of 25 kg K2O/ha as basal was most economical in terms of IBCR indicating the utility of K applications for resource poor farmers. The negative balance of K in all the treatments, except with the application of 75 kg K 2O/ha as basal to both the crops of the system, brought out the need for reorienting the present recommended levels of K to meet the system need and enhance system efficiency in sustainable way.

About thirty-five diseases are commonly occurring in different parts of India. Twenty out of them are considered as major based on the magnitude of yield losses they are causing. Annual yield losses from diseases in soybean are in the tune of 12% of the total production. Eleven diseases viz. rust, anthracnose, Cercospora blight, powdery mildew, charcoal rot, sclerotial blight, bacterial pustule, yellow mosaic, soybean mosaic, bud blight like malady and no-podding syndrome are distributed throughout the soybean areas of the county while others like Myrothecium leaf spot, frogeye leaf spot, target leaf spot, brown spot, Fusarium root rot, pod & stem blight, Rhizoctonia root rot and aerial blight, bacterial blight etc are restricted to some regions only. In India, during 1994, a loss of 4.2 lakh metric tones was estimated on account of anthracnose, Fusarium root rot, pod & stem blight, Rhizoctonia aerial blight, bacterial and viral diseases. For the management of diseases, a general package and some disease specific packages of recommendations are being developed and endeavours are on the way to transfer them to farmers in toto. But at large, chemical control is more practiced by farmers, as it is usually effective. At times it becomes highly uneconomical and impractical to the farmers. Therefore, farmers are now being convinced to pursue integrated approach for soybean disease management. The main integrated disease management practices followed by farmers are deep summer ploughing, crop rotation, intercropping, use of balanced fertilizers, cultivation of disease resistant/tolerant varieties with varietal cafeteria approach, avoiding deep sowing, optimum seed rate and plant population, seed treatment, sanitation and roguing of infected plant parts and plants and chemical sprays. For chemical management of diseases, pre-planting seed treatment with thiram + carbendazim 2:1 at 3g/kg for the control of seed borne fungal diseases, with thiamethoxam 70 WS at 3 g/kg seed for yellow mosaic is recommended. Seed treatment with Trichoderma viride at 4-5 g/kg seed is also recommended and practiced by the farmers. For the management of (i) foliar and pod diseases, two sprays of carbendazim 50 WP or thiophanate methyl 70 WP at 0.05% (ii) bacterial pustule, streptocycline 0.02% + COC 0.2%, (iii) soybean rust, sprays of hexaconazole 5EC at 0.1% or propiconazole 25EC at 0.1% or triadimefon 25EC at 0.1% (iv) for yellow mosaic and soybean mosaic spray of thiamethoxam 25 WS at 100 g/ha 7 days after germination or ethafenprox or methyl demeton at 1l/ha are recommended. A computerized symptom-based disease diagnosis system for correct identification of diseases and their appropriate management has been developed at this center.

Infection of pearl millet by downy mildew [Sclerospora graminicola (Sacc.) Schrot.] has been shown to be influenced by soil pH, soil bulk density, soil moisture content and addition of farmyard manure and nitrogen fixing bacteria. A pH value of 8.5 allowed disease to develop the most, with increases in acidity to pH 7.5 producing 70 % reduction in disease. Higher soil bulk density and moisture content also led to reductions in disease but the effects were not as marked as for pH. The addition of farmyard manure to soil or the addition of Rhizobium, Azospirillum or Azotobacter inocula as combined seed and soil treatment also reduced disease with the best effects being from a cluster bean isolate of Rhizobium and from Azotobacter chroococcum. Assessment of rhizosphere microorganisms associated with the resistant and susceptible varieties of pearl millet showed that, overall, the fungal population was lower in the resistant varieties but that it was increased in both susceptible and resistant varieties by infection with downy mildew. Bacterial and actinomycete populations were also lower in resistant varieties but in this case downy mildew infection decreased the rhizosphere populations of both groups. Dehydrogenase activity of rhizosphere soil was higher in susceptible varieties but was decreased in both variety types by infection with S. graminicola. The results are discussed with reference to possible mechanisms to explain the observed effects.

To estimate the loss caused by downy mildew, two separate experiments were conducted on pearl mil let cv. HE 3. Mi Id infection of downy mildew increased the fresh weight of the shoot and the number of basal and nodal tillers, but severe and systemic infection reduced all of them. Dry matter (%) increased with infection. Plant height and test weight were inversely related to the infection. Reduction in grain yield in categories 5, 4, 3 and 2 plants was of the order of 97, 65, 26 and 9% respectively over the category 1 (healthy plants). Based on the incidence level of 62%, the estimated yield loss was 34% over the healthy crop. The yield reduction was 57% when the yield of the unprotected crop was compared with the yield of the protected crop.

Large-scale cultivation of pearl millet [Pennisetum glaucum (L.) R. Br. F1 hybrids in India has led to increased incidence of downy-mildew (Sclerospora graminicola). There is concern that the A1 male-sterile cytoplasm used in all the hybrids released so far is responsible for this increase. The influence of A1 malesterile cytoplasm on downy-mildew incidence in pearl millet was studied by comparing the disease reaction of 40 pairs of F1 hybrids, each pair carrying respectively a1 male-sterile and normal B cytoplasm. Mean downy-mildew incidence was similar in the hybrids carrying either A1 male-sterile or B cytoplasm. The general combining ability of lines with and without A1 cytoplasm was found to be similar for downy-mildew incidence. These results indicated that in pearl millet A1 cytoplasm is not associated with increased downymildew incidence. The possible danger of using only one source of cytoplasm has been briefly discussed.

Blossom wilt, an important phase of the brown rot disease, resulting in crop losses in apricot and almond, is reported for the first time from North India. Based on general morphology, cultural and sporulation characteristics, and isoelectric focusing profiles, the causal fungus was identified as Monilinia laxa.

A study was conducted during 1982 and 1983 to determine the effect of tillage and mulching on soil environment and cowpea (Vigna unguiculata cv. FS-68) seedling growth under arid conditions. One disking and three diskings with a disc harrow up to 15-cm depth improved the soil environment and increased the final seedling emergence count, but did not affect the population of Macrophomina phaseolina in soil. Disking also increased plant growth and markedly reduced seedling mortality. Placement of weed mulch in-between the crop rows at the rate of 6 t ha−1 along with disking treatments significantly increased the mean moisture status of the 15-cm soil depth by 1.4% on a dry weight basis (Pw), significantly decreased the mean maximum temperature of the 10-cm depth (measured at 2 p.m.) by 3.9°C and thus increased plant growth and dry matter production. Mulching also markedly reduced the population of M. phaseolina and the mortality of the cowpea seedlings.

International Journal for Numerical Methods in EngineeringVolume 6, Issue 2 p. 303-304 Article Discussion of a paper† by D. H. Ferriss G. K. Gupta, G. K. Gupta Department of Information Science, Monash University, Clayton, Victoria, AustraliaSearch for more papers by this author G. K. Gupta, G. K. Gupta Department of Information Science, Monash University, Clayton, Victoria, AustraliaSearch for more papers by this author First published: 1973 https://doi.org/10.1002/nme.1620060215 † ‘The numerical calculation of turbulent boundary layer development’, Int. J. num. Meth. Engng. 4, 109–122(1972). AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Volume6, Issue21973Pages 303-304 RelatedInformation