Large Headsetts and Improved Cultivar Enhance Growth and Development of Taro (Colocasia esculents [L.] Schott) During Establishment

Small, medium and large headsetts of a traditional ( Nine ) and an improved ( Alafua Sunrise ) cultivar of taro were grown for 33 days in pots in a screenhouse.
Differences between the cultivars were greatest in root growth where density of root primordia, number of primary roots and root surface area at the final harvest were 53, 82, and 60 % greater respectively in the improved over the traditional variety. Relative rate of leaf elongation and leaf appearance rate were about 30 % faster in the improved variety. Correlation between leaf area and root surface area was cultivar dependent.
Large headsetts produced more primary roots and a larger root surface area than small headsetts. They also produced 46 % more leaf area than small headsetts because of larger individual leaves, but not the rate of leaf appearance.
Dry matter and nitrogen content declined in petioles, remained relatively constant in corm and accumulated in new shoot and root during establishment. Losses of N were similar but accumulation was greater in new growth of Alafua Sunrise than Niue.
We conclude that differences in productivity between the improved and traditional cultivars used in this experiment are at least partly attributable to differences in rate of development of new shoot and root during establishment. Previously reported correlations between corm yield and size of planting material are probably due to large headsetts producing a greater area of leaf and root than small headsetts during early growth.     

Designing sustainable agriculture education: Academics’ suggestions for an undergraduate curriculum at a land grant university

Historically, land grant universities and their colleges of agriculture have been discipline driven in both their curricula and research agendas. Critics call for interdisciplinary approaches to undergraduate curriculum. Concomitantly, sustainable agriculture (SA) education is beginning to emerge as a way to address many complex social and environmental problems. University of California at Davis faculty, staff, and students are developing an undergraduate SA major. To inform this process, a web-based Delphi survey of academics working in fields related to SA was conducted. Faculty from colleges and universities across the US were surveyed. Participants suggested that students needed knowledge of natural and social science disciplines relating to the agri-food system. In addition, stakeholders suggested students learn through experiences that link the classroom to field work, engaging a broad range of actors within applied settings. Stakeholders also emphasized the need for interdisciplinary and applied scholarship. Additionally, they proposed a range of teaching and learning approaches, including many practical experiences. Given the diverse suggestions of content knowledge and means of producing knowledge, the survey presented unique challenges and called into question the epistemological and pedagogical norms currently found in land grant colleges of agriculture. This study has implications for land grant universities seeking to develop undergraduate curriculum appropriate to the field of SA. Damian M. Parr is a doctoral student of Agricultural and Environmental Education, in the School of Education at the University of California at Davis. His professional interests include organic farming, sustainable agriculture, experiential and transformational learning, critical pedagogy, and participatory action research. He is currently working on linking on-campus student initiated sustainable farm and food systems projects to curricula at land grant universities Cary J. Trexler is an assistant professor of Agricultural and Environmental Education at the University of California at Davis where he teaches courses in the history of agricultural education, experiential learning, and research methods for practicing teachers. His research focuses on experiential learning, sustainable agriculture education, and needs of teachers and informal educators within the context of the agri-food system Navina R. Khanna is a graduate student pursuing an MS in International Agricultural Development at the University of California at Davis. She is committed to facilitating community dialogue and education about sustainability issues. Her work at the university focuses on the process and goal of sustainability in agricultural education and campus food system sustainability. Her primary professional interests include democratic participatory process in agri-food system sustainability and urban revitalization Bryce T. Battisti is a doctoral student of Agricultural and Environmental Education, in the School of Education at the University of California at Davis. His research interests include the development of alternative models for university education that are founded on student-centered experiential learning. Specifically, he studies models of permaculture education that lead toward accredited degrees and relates these models to sustainable agriculture degree programs     

Integrated multi-enterprise agricultural system for sustaining livelihood,energy use and resource recycling: a case study from semi-arid tropics of central India

Agroforestry Systems - Integrated farming system (IFS) has been the way of life of agrarian people in semi-arid tropics (SAT) of India and other developing countries. However, there has been losing...     

Preparation of poly(acrylonitrile)-grafted silk fibers with antibacterial properties

This study is focused on investigating the feasibility of using silver(I) ions loaded poly(acrylonitrile)-grafted silk fibers as antibacterial dressing material. The optimum grafting conditions for ceric ammonium nitrate induced graft-copolymerization of acrylonitrile onto silk fibers were found to include initiator concentration of 35 mM, catalyst HNO₃ concentration of 0.40 M and initiation time of 10 min. The poly(acrylonitrile)-grafted silk fibers were loaded with silver(I) ions by equilibration method. The resulting fibers were investigated for their biocidal action against E. coli, by using zone inhibition and colonies counting method.     

Studies on the Breeding of Pangasius sutchi Using Different Inducing Agents

A breeding experiment on Pangasius sutchi was conducted from July 2008 to September 2008 in a hatchery in West Bengal, India, using three different inducing agents, each injected at two different dosages: carp pituitary extract (CPE) and two synthetic hormones, Ovaprim and Ovatide. The fertilization rate was 82% to 91%. Hatching took place within 34 to 36 hours from the time of fertilization, with a hatching rate 73% to 79%. The response to spawning with CPE was best with Ovatide and Ovaprim in terms of percentage of fertilization, high hatching rate, and ease of stripping.     

Correlation between morphological,chemical and RAPD markers for assessing genetic diversity in Withania somnifera (L.) Dunal

Genetic diversity among 14 Withania accessions were studied using morphological, chemical, and RAPD (Rapid Amplification of Polymorphic DNA) markers. On the basis of morphological variation and maximum assimilation of chemical constituents, wild accessions were considered elite as compared to cultivated. The molecular study showed that a total of 12 DNA fragments were amplified with five random decamer primers 75% of which were polymorphic. Genetic similarity matrix based on the Dice index detected coefficients ranging from 0.556 to 0.941. These coefficients were used to construct a dendrogram using unweighted pair group method with arithmetic mean (UPGMA). These accessions were clustered into two major groups; the first group included AGB-009, AGB-012, AGB-042, AGB-030, AGB-053, AGB-019, AGB-017, AGB-002, and AGB-003; the second included AGB-025, AGB-001, AGB-036, AGB-015, and AGB-055. The highest similarity among the Ashwagandha accessions was observed between AGB-009 and AGB-030, AGB-009 and AGB-012, AGB-042 and AGB-030, AGB-025 and AGB-001, AGB-036 and AGB-015, AGB-015 and AGB-055 and between AGB-015 and AGB-055. The most distant populations in the dendrogram were AGB-053 and AGB-055. The combination of morphological, chemical, and molecular markers assessment will be useful in studying the genetic diversity of Withania for identification, conservation, breeding, improvement activities, and in order to achieve elite type in terms of bioactive metabolites.     

Use of urea coated with natural products to inhibit urea hydrolysis and nitrification in soil

Laboratory incubation experiments were conducted with uncoated urea or urea coated with dementholized oil (DMO), pitch (the mint oil discard), terpenes (the products of menthol mint oil), or dicyandiamide (DCD) to study the retardation of urea hydrolysis and nitrification in soil. Two levels (0.5 and 1 %) of coating were tested. Urea was applied at a rate of 200 mg kg⁻¹ of dry weight of soil. The urea hydrolysis and nitrification processes were inhibited by all three natural products. All the three natural products viz., DMO, terpenes, and pitch significantly retarded urease activity of soil.