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Policy-makers, research managers, and donors are interested in knowing the outputs, outcomes, and impacts of investment in agricultural research. Several institutions are engaged in rice research and impact assessment of rice research requires area coverage information for rice varieties. The area coverage information for individual varieties is not available at the national level in many developing countries as the conventional household survey method is expensive and time-consuming. This article aims to find a cost-effective and quick method to estimate the area under popular rice varieties in India and their spread in different states. Secondary data collected from 27 states and 1 union territory of India were used to estimate the area. The results of the new method compared well with some of the studies conducted at the state level. The most important varieties identified using the new method were Swarna, Cottondora Sannalu, Samba Mahsuri, Vijetha, IR-64, and Ranjeet, which covered more than 1 million ha each in the country. On geographical coverage, IR-64 has spread to 17 states followed by Swarna, Cottondora Sannalu, Samba Mahsuri, Vijetha, IR-36, and Swarna Sub-1 which covered 14, 14, 12, 11, 11, and 10 states, respectively. The area information can be used to compute returns to rice research by different research institutions and study dynamics of varietal change over time. The popular varieties identified should be used in future breeding programs and biotechnological studies for the development of superior varieties.

Application of pesticide in agricultural fields is “unnecessary evil” for non-target microflora and fauna. Hence, to identify the safer pesticide molecules against non-target microbes, a long-term pesticide experiment was initiated at National Rice Research Institute, Cuttack, India. In the present study, the effect of continuous application of chlorpyrifos (0.5 kg ha −1 ) in rice fields on non-target groups of soil microbes and nematodes was studied for seven seasons (four wet and three dry seasons) during 2009–2013. Treatments were arranged in a randomized complete block design with four replications of chlorpyrifos-treated (0.5 kg a.i. ha −1 ) (CT) and untreated control (UT) plots. During seven seasons of experimentation, regular application of chlorpyrifos had no significant effect on population of heterotrophic aerobic, anaerobic, oligotrophic and copiotrophic bacteria in CT compared to UT, whereas, population of asymbiotic aerobic nitrogen fixer, nitrifiers, denitrifiers, gram positive and spore-forming bacteria were significantly reduced by nearly 0.25–2 fold in CT than UT. However, comparatively less deviation in population of actinomycetes, fungi, phosphate solubilizing and sulfur oxidizing bacteria were observed in CT than UT. Significant interactions were found between effects of chlorpyrifos with time in population dynamics of microbes. In plant parasitic nematode species, Meloidogyne graminicola (RRKN) and Hirschmanniella spp. (RRN), were significantly lower (p<0.01) in CT compared to UT after first year onwards. The overall observation of five years data indicated that the RRKN population showed a decreasing trend (R 2 =0.644) whereas RRN showed increasing trend (R 2 =0.932) in CT. The drastic chlorpyrifos dissipation was noticed after 15 days of application from the initial residue of 0.25 mg kg −1 soil, which indicated that chlorpyrifos residue in rice field soil was not persistent and its half-life was found to be 4.02 days. Overall, the present findings revealed that non-target effect of repetitive application of chloropyrifos (0.5 kg ha −1 ) on soil microbes and nematodes was found less under rice-rice cropping system. [ABSTRACT FROM AUTHOR]

Irregular two-level fractional factorial designs are the plans that can not be specified in terms of defining contrasts. The aliasing properties of irregular fractional factorial plans can be explained by using minimum moment aberration and moment aberration projection criterion. In this paper a method of construction for irregular minimum aberration fractional factorial designs of the type r2^{p}/2^{k}, where r is a prime number has been given. Also minimum aberration designs have been constructed for r=3, p=2 and k=4, 5, 6, 7; for r=3, p=3 and k=5, 6, 7, 8; for r=5, p=3 and k=5, 6, 7, 8 and r=7, p=3 and k=5, 6, 7, 8 by using the two criteria, viz. minimum moment aberration and moment aberration projection. [ABSTRACT FROM AUTHOR]