Effect of staking and non-staking systems on disease severity, yield and quality attributes of yams (Dioscorea alata)

Aims: The aim of this study was to evaluate the effect of staking and non-staking systems on disease severity, yield and quality attributes of yams. Methodology: High costs and lack of planting materials, labour, staking and inappropriate knowledge on production techniques are major constraints of yam production in Sierra Leone. A total of seven promising hybrid genotypes of yams from International Institute of Tropical Agriculture and one local cultivar, Pulli, were evaluated for yield, reaction to local pest and disease and desirable market traits during 2011 and 2012 in three agro-ecological zones of Sierra Leone. The experiment was laid out in randomized complete block replicated thrice at the experimental sites of the Njala Agricultural Research Centre. Results: Results revealed higher disease pressure in non-staked plots compared to staked plots. Fresh tuber yields were significantly higher in staked plots than the non-staked plots. Five genotypes with yields ranging between 11.8 and 14.7 t.ha-1 significantly out-yielded Pulli (9.1 t.ha-1) in the staked plots, while only genotype TDa 02/00012 (11.9 t.ha-1) significantly out-yielded Pulli (7.1 t.ha-1) in the non-staked plots. Farmers’ preferences for all genotypes were similar to that of the local cultivar. Staking contributed 30.5% mean yield increase compared to non-staking. Makeni had the highest percent mean yield increase due to staking (38.5%) compared to Njala (29.7%) and Kenema (26.4%). Conclusion: Staking is beneficial in yam production contributing an average of 28.2% more fresh tuber yields than non-staking. Genotypes in staking system were more tolerant to in-field local diseases, thereby significantly out-yielding those in non-staking system. Genotypes TDa 98/01174, TDa 98/01176, TDa 02/00012, TDa 98/01168 and TDa 00/00194 had stable resistance to in-field diseases in the staking system and desired food quality traits compared to the check variety, Pulli. Findings have good implications for multiple disease resistance breeding for various production systems as the different genes controlling these traits could be pyramided into an ideotype. Similar technique could be used to breed for yield and other desired food quality traits

Defining the Critical Hurdles in Cancer Immunotherapy

ABSTRACT: Scientific discoveries that provide strong evidence of antitumor effects in preclinical models often encounter significant delays before being tested in patients with cancer. While some of these delays have a scientific basis, others do not. We need to do better. Innovative strategies need to move into early stage clinical trials as quickly as it is safe, and if successful, these therapies should efficiently obtain regulatory approval and widespread clinical application. In late 2009 and 2010 the Society for Immunotherapy of Cancer (SITC), convened an "Immunotherapy Summit" with representatives from immunotherapy organizations representing Europe, Japan, China and North America to discuss collaborations to improve development and delivery of cancer immunotherapy. One of the concepts raised by SITC and defined as critical by all parties was the need to identify hurdles that impede effective translation of cancer immunotherapy. With consensus on these hurdles, international working groups could be developed to make recommendations vetted by the participating organizations. These recommendations could then be considered by regulatory bodies, governmental and private funding agencies, pharmaceutical companies and academic institutions to facilitate changes necessary to accelerate clinical translation of novel immune-based cancer therapies. The critical hurdles identified by representatives of the collaborating organizations, now organized as the World Immunotherapy Council, are presented and discussed in this report. Some of the identified hurdles impede all investigators, others hinder investigators only in certain regions or institutions or are more relevant to specific types of immunotherapy or first-in-humans studies. Each of these hurdles can significantly delay clinical translation of promising advances in immunotherapy yet be overcome to improve outcomes of patients with cancer

Current status of root and tuber crops improvement, production and utilization in Sierra Leone

Cassava (Manihot esculenta Crantz) is the second most important food crop after rice, the staple in Sierra Leone; it is also the most important root and tuber crop. It is followed by sweet potato (Ipomoea batatas L.), yam (Dioscorea spp.), which forms part of the traditional farming system and has only recently been included in the research agenda of NARC/SLARI and potato (Solanum tuberosum L) aka “Irish” potato in Sierra Leone, an introduced crop from neighbouring Republic of Guinea. Genetic improvement of the above crops is mainly through introduction of exotic germplasm from the International Institute of Tropical Agriculture (IITA) at Ibadan, Nigeria; and screening, selection and advancement of promising lines in a participatory manner with farmers and other stakeholders in the crop development process. Breeding objectives of the above crops are aimed at addressing the devastating problem of pests and diseases prevalent in Sierra Leone, cassava mosaic disease (CMD), cassava bacterial blight (CBB), green mite, mealy bug and grasshoppers; sweet potato virus x and scab, and late blight of potato), yield and quality for the various desirable traits of eating, processing and potential industrial uses. Several genotypes of cassava have been released in the recent past (SLICASS 1-6) with yield range of 25-35 mt/ha whilst new and more nutrient-rich genotypes including yellow rooted ones with yield range of 40-50 mt/ha are in the pipeline for release. The yield ranges of sweet potato, yam and potato are 6-10 mt/ha, 10-27 mt/ha and 2-4 mt/ha, respectively. Four potato varieties (SLIPOT 1-4) were recently released to the farming population of Sierra Leone. The current status of cassava, sweet potato (including recent and more nutritious, âcarotene genotypes), yam and potato breeding activities at NARC/SLARI, Sierra Leone is summarized and presented. Yam and potato improvement is new but significant strides have already been made in identifying promising lines of the former with the desirable traits or qualities that are acceptable to both farmers and consumers alike in the country. Production of cassava has increased more than three folds since the end of the civil war in 2002, during which period it served as the most easily cultivated, accessible and affordable food crop, along with sweet potato to the majority of the then internally displaced population (IDP). Recent trends in production of these two crops are also given. Cassava transformation into many useful food products, especially gari, fufu and high quality cassava flour (HQCF) is receiving tremendous boost in many parts of the country by both regional and national projects (CFC/IITA/SLARI) Cassava Value Addition, USAID/IITA-Sierra Leone Unleashing the Power of Cassava in Africa (UpoCA), AfDB/FARA/CORAF/WECARD/ SLARI Promotion of Science and Technology for Agricultural Development (PSTAD) in Africa Project (Dissemination of New Agricultural Technologies in Africa (DONATA) and Regional Agricultural Information Learning Systems (RAILS), Non-Governmental Organizations (NGOs) and the private sector. Strides made in that direction are also summarized and presented. On a lesser scale, processing of sweet potato into more durable and useful by-products such as flour is beginning to receive the necessary attention by scientists at NARC/SLARI, and Njala University (NU), Sierra Leone and the Federal University of Agriculture at Abeokuta (UNAAB) and Association of African Universities (AAU) Regional Food Developers Initiative (FDI) Project, Nigeria. This will hopefully prevent market glut and improve the livelihood of root and tuber crops farmers with a consequent reduction in poverty