Prospects for Intensifying Soil Fertility Management on the Growth and Yield of Assava in Ghana

Crop-specific fertilizer recommendations are necessary to improve yield and enhance food security in Ghana. This approach would help in improving crop productivity while maintaining a good soil health status. A new NPK fertilizer has been recently developed by the private sector with Nitrogen (N), Phosphorus (P), and Potassium (K) proportions of 11:22:21 respectively for improved cassava root yield. This study evaluated the right and economic rate of this fertilizer to apply for improved cassava productivity and farmer livelihoods. Rates of 0, 300, 400, 600, and 800 kg/ha of newly developed fertilizer were applied at Fumesua and Akumadan located in the forest agro-ecological zone, and at Ejura and Techiman located in the transitional agro-ecological zone of Ghana. The experiments were conducted in two growing seasons (May 2019 to April 2020 and May 2020 to April 2021). Increases in cassava growth were observed with the increasing levels of fertilizer at all locations and in the two growing seasons. Cassava yield was in the linear phase of the fertilizer response curve. It ranged from 28 to 52 tons/ha with the increasing fertilizer levels. Cassava in the forest agro-ecology had better growth and 25% more yield than other locations. Fertilizer rates between 0 and 400 were found to have the best yield returns and sufficient profit opportunities to sensitize adoption by financially constrained farmers. The results indicate that the newly developed fertilizer (11:22:21 N:P2O5:K2O) can improve cassava productivity in the inherently poor soils of Ghana. Keywords: fertilizer recommendation; plant nutrients; rainfall; agronomic practices; cassava productivity; root yield DOI: 10.7176/JBAH/12-18-03 Publication date:September 30th 202

Assessing Flood Tolerance Potential of Papaya Germplasm at the Juvenile Stage

Aims: To assess flood tolerance potential of papaya germplasm and determine physiological basis of observed tolerance. Study Design: Both Experiment 1 and 2 were in RCBD with 2 and 3 treatments respectively. Place and Duration of Study: Experiments were conducted in a screen-house at the Kwadaso Station of Crops Research Institute, Ghana between February and September 2014. Methodology: Six weeks old seedlings of 30 papaya accessions were subjected to 90% partial flooding (F90) by standing planting bags with seedlings in 15 L bucket filled with water up to 90% of height of soil level in bags. Control (non-stressed: NS) plants were watered regularly for 1 week. Post flooding recovery of seedlings was monitored for 1 week. In Experiment 2, seedlings of 6 papaya accessions were subjected to 100% flooding (F100) or 50% partial flooding (F50) for 5 weeks, and a post flood recovery period of 6 weeks. Plant height, girth and biomass were measured together with leaf SPAD chlorophyll content, chlorophyll fluorescence, RWC and senescence. Results: None of the 30 papaya accessions had high flood tolerance potential, with 60% of accessions studied having low flood tolerance. F90 plants had reduced height and girth relative to control (p<.001). Leaf senescence was high in F90 plants (p<.001). All six accessions used in Experiment 2 could not withstand 100% flooding longer than 3 days. F50 treatment increased lateral root biomass (p<.001), although controls had higher tap root (p<.001), total root (p=.02) and total plant biomass (p=.002) than F50 plants. Leaf RWC (p=.89), SPAD chlorophyll content (p=.05) and chlorophyll fluorescence (p=.24) were not negatively affected by F50 treatment. Conclusion: None of the papaya accessions studied was able to withstand complete flooding. However, most could tolerate partial flooding of roots for 5 weeks and resume normal growth after release from flood stress