A 2-year field experiment was conducted in 2012 and 2013 at the research fields of CSIR-Crops Research Institute to determine the best agronomic practices for the field establishment and cultivation of Chia (Salvia hispanica) and determine insect pests and diseases associated with the plant. The study also determined the nutritional composition of the plant under Ghanaian environment. A split-plot field trial with 2 planting methods (direct planting with seed; planting from seedling) as main plot and 3 planting density (10,000 plants/ha; 20,000 plantst/ha; 40,000 plantst/ha) as subplot were used for the agronomic evaluation of the plant. A sweep net was used to sweep diagonally across the field under two separate regimes to collect insects on the crop for the entomological investigations. Major insects collected were coreid bugs, lagria sp., Zonocerus variegatus and Diopsis thoracica. The method used for the pathological investigations were the moist blotter test and culture of pathogens on Potato Dextrose Agar. The results of the study in both years show high biomass and seed yield of chia when the crop was planted directly in the field. Narrow-row spacing of 0.5m x 0.5m consistently produced the highest biomass and seed yield in both years of the study. The results indicated that interaction between planting method and planting density positively influenced most of the growth and yield parameters of Chia plants. Nutritional profile analysis from the Chia seeds shows medium to high proximate and mineral composition. Disease evaluation revealed evidence of Fusarium wilt infection on Salvia hispanica in the field. The study recommends the adoption of direct planting method and narrow-row spacing (0.5m x 0.5m) (SP3) as the best option for the production of Chia plants in Ghana.

A participatory breeding programme involving farmers in two Ghanaian communities and scientists from CRI (Ghana) and NRI (UK) to develop superior cassava cultivars is described. Initial situation analyses of the communities indicated that cassava is increasing in importance both as a food and a cash crop. Most farmers utilised landraces of cassava; modern varieties were scarcely mentioned. Seeds of 16 half-sib families obtained from a crossing block in Nigeria at the International Institute of Tropical Agriculture were planted in a field in each community. During seedling and subsequent clonal generations, accessions selected either by farmers or scientists were retained to the next generation. This selection process has identified 29 superior accessions from amongst 1350 original seedlings. Farmers were relatively consistent in their selection from year to year and their selections corresponded with their stated criteria. Official variety release requires additional multilocational and inspection trials and postharvest assays but otherwise seems harmonious with a participatory breeding approach; our early involvement of farmers may facilitate early release, an important factor in cost-effectiveness. A stakeholder workshop confirmed the need for improved markets for cassava; surveys of current and potential markets have led to field trials with cassava processors. Adoption of a participatory approach, with farmers and scientists taking on new roles and decentralisation of activities, implies a concomitant transfer of influence and resources.

The study evaluated staking options to address the problem of deforestation for sustainable yam production in the Forest and Forest-Savannah Transition zones of Ghana. A split-plot design with three yam varieties (Dente, Water Yam and TDR95/19177 line) and three staking options (No staking, Vertical staking and Trellis with 50% and 30% number of vertical stakes for 2012 and 2013 respectively) as main plots and subplots respectively were used. Results revealed a significant (P < 0.05) interaction between yam variety and staking options on yam tuber yields in both locations and years. While water yam had similar tuber yields under all staking options, Dente and TDR95/19177 under no staking had significant yield reductions ranging from 37 to 65% compared to the other staking options. The observed yield reduction under no staking of Dente and TDR95/19177 could be attributed to higher incidence of yam mosaic virus leading to significantly lower fresh leaf biomass production. Reducing the number of stakes in trellis to as low as 30% of the vertical/optimum staking option did not result in a significant reduction in tuber yields for TDR95/19177 and Water yam. The economic analysis revealed that it is more profitable to produce water yam and TDR95/19177 under no staking and trellis (50% and 30% number of optimum staking) respectively in both locations. The results suggest trellis/minimum staking can be used to minimize the use of stakes, yam mosaic virus disease infection and for sustainable yam production in the face of climate change.

Barley yellow dwarf luteovirus (BYDV) was detected in field grown Miscanthus sacchariflorus propagated from root cuttings. Inoculation of BYDV to M. sinensis plants grown from seed had an adverse effect on shoot growth and leaf development.Plant biomass is an energy resource and there is renewed interest in investigating the potential of growing plants and trees as fuel crops to utilize set-aside arable land.One plant genus under investigation at Rothamsted is the oriental grass, Miscanthus. There are about 20 species of Miscanthus, and cultivars of M. sinensis and M. sacchariflorus are of most interest because they have potential to give high yields of dry matter. Dry matter yields from sites in Europe ranged between 12 t and 44 t per ha per year [Harvey and Sylvester Bradley, 1992] but there are no data on yield in the UK.There have been few reports of the susceptibility of Miscanthus spp to disease. In Taiwan, native species of Miscanthus have been found to be highly resistant to Culicolus smut Ustilago scetaminea and downy mildew Peronosclerospora sacchari and breeding programmes are being used to transfer this resistance to Saccharum -Miscanthus hybrids [Chen and Lo, 1988]. A geminivirus has been identified from M. sacchariflorus in Japan [Yamashita et al., 1985] but the insect vector is unknown.We report here the identification of barley yellow dwarf luteovirus (BYDV) in M. sacchariflorus and M. sinensis grown in the UK from micropropagated plants imported from Germany and the effects of infection on seedlings of M. sinensis.Barley yellow dwarf is a disease with a worldwide distribution and many members of the Gramineae are susceptible including all cereals and many grasses. Infection of small grain cereals can decrease yield by 50% or more and affect the quality of the grain; infection of pasture grasses can decrease dry matter yield by 20% [Bruehl, 1961;Plumb, 1992]. During a field study at Rothamsted of M. sinensis 'Giganteus' and M. sacchariflorus in 1992,

The grass species Miscanthus sinensis, Echinochloa crus‐galli and Phalaris arundinacea may be useful biomass crops. In glasshouse inoculations with two isolates of Barley yellow dwarf virus (BYDV)‐MAV and BYDV‐PAV and one of Cereal yellow dwarf virus (CYVD)‐RPV, E. crus galli was infected by all three virus isolates, P. arundinacea by BYDV‐MAV and CYDV‐RPV, but M. sinensis only by BYDV‐MAV. All three hosts became very difficult to infect after several weeks’ growth. Symptoms were inconspicuous; dry matter yield losses ranged from c. 20–40%. Aphids acquired all three virus isolates from E. crus‐galli, but more efficiently from 5 than 26‐week‐old plants. Only BYDV‐MAV was acquired from P. arundinacea and M. sinensis. Plants of each species and of Avena sativa were grown outdoors between May and July in 1994 and 1995. Young plants of each species were exposed for successive 2‐week intervals during the same periods. Vector populations were higher on A. sativa and P. arundinacea than on E. crus‐galli and M. sinensis, and more plants of these species became infected. In 1994 only BYDV‐MAV was detected. In 1995 BYDV‐MAV, BYDV‐PAV and CYDV‐RPV were all detected; BYDV‐MAV was again the virus isolate most frequently found.