No abstract

A major impediment to breeding for resistance to Asian soybean rust (Phakopsora pachyrhizi) is the lack of stable sources of resistance, due to high variability in the pathogen. The objectives of this study were to assess comparative virulence of five diverse field isolates from major soybean producing areas in Uganda, and identify lines with resistance to isolates of soybean rust in seedling and adult plants under screen house and field conditions respectively. When inoculated with the five field isolates, all twelve lines evaluated showed diverse and mixed reactions, suggesting each location differed in soybean rust races and/or virulence. Experimental sites growing many diverse soybean lines yearly had the greatest diversity of soybean rust. The effectiveness of specific resistance genes was restricted to certain locations and gene Rpp2 previously resistant was ineffective producing a susceptible tan reaction at the seedling stage. A positive correlation between mean lesion density at the seedling stage and adult plant severity indicated that using field isolates to screen for seedling resistance can be a useful breeding approach to extrapolate resistance in adult plants. Overall, these results emphasise the relevance of using field isolates from the target areas to evaluate lines for soybean rust resistance.

No abstract

No abstract

No abstract

No abstract

Less or no fertilizer use compromises growth and yield of cherry tomato (Solanum lycopersicum var. Cerasiforme) in Uganda. A study was conducted to determine the effect of nitrogen (N) and potassium (K) fertilizer rates on cherry tomato growth and yield. The experiment was conducted in a field during 2016B and 2017A seasons at Namulonge. The treatments included; (100, 60, 100) and (200, 60, 200) kg ha-1 of N, P, K and the control with no fertilizer application, these were laid out in a split plot design with three replications. Results revealed that tomato plants significantly (P < 0.05) responded to nitrogen and potassium fertilizer application by increasing their height and yield. The highest tomato height and yield were obtained from plots applied with 100, 60, 100 kg ha-1 of N, P and K. This rate was considered as the optimal application rate because plants applied with fertilizer above this rate were observed to have low height and yield. On the other hand, plants applied with nitrogen and potassium fertilizers below 100, 60, 100 kg ha-1, flowered and matured earlier than those in the control plots. The study showed that N and K fertilizer influenced plant height, flowering, maturity period and yield of cherry tomato. Based on these findings, use of 100, 60, 100 kg ha-1 of N, P and K is recommended for improving cherry tomato production in central Uganda, where the study was conducted, and any fertilizer rate above 100, 60, 100 kg ha-1 in the same area may be un-economical to use in cherry tomato growing.

Sorghum [Sorghum bicolor (L.) Moench] is one of the most important cereals worldwide with great genetic diversity. Like most small grains it has good adaptation to drought prone and marginal areas were other cereals are not productive. Globally, sorghum has been underutilized compared to other cereal staple crops however, there is growing interest in sorghum and its related products due to its unique nutritional traits, crop physiology and phenology. Given the genetic variability of sorghum there is great scope to use the crop to produce an array of commodities in the food, feed, industrial and bioenergy sector. This review paper presents sorghum genetic diversity and with special reference to bio-based and value added products such as gluten free, high protein, aromatic, syrup, popping, weaning, pet food, baked products and alcohol free malt beverages that can be explored in Africa to popularize it and improve livelihoods.