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.

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Agriculture in rainfed dry areas is often challenged by inadequate water and nutrient supplies. Responses to these challenges include adequate fertilization, but it is unknown whether different nitrogen (N) rates from that commonly used in the Loess Plateau can alleviate this issue. Field experiments were conducted over three cropping seasons to investigate the effect of different N fertilization levels on soil water dynamics, photosynthetic activity, and grain yield of maize (Zea mays L.) grown in the Western Loess Plateau of China. Fertilizer was applied at planting at rates between 0 and 300 kg N ha−1 at regular increments of 100 kg N ha−1 (referred to as N0 and N300, respectively), and treatments were arranged in a complete randomized block design. Results showed that water use efficiency in the N200 and N300 treatments was ∼60% higher than N0 and N100 (P < 0.05), which translated into increased crop biomass and therefore grain yield (≈70–80%). These observations were consistent with all measurements of photosynthetic traits and suggested that, under the conditions of this study, the ecophysiological response of the crop may be optimized at N application rates in the range of 200 to 300 kg ha−1, depending on soil water availability. Agronomic efficiency calculations at this level of N fertilization reported consistently higher values and consequently suggested that environmental losses of applied fertilizer N were small. The current experimental results for the N application rates in the range of 200 to 300 kg ha−1 could be useful for improving N fertilizer and soil water management practices of maize production while maintaining a relatively stable yield level in rainfed dry areas. Future work should focus on optimizing timing and improving the placement of fertilizer N applied to maize.