Striga hermonthica is a parasitic weed species that causes considerable yield loss in susceptible maize cultivars in western Kenya. A generation means analysis was conducted to estimate gene effects influencing resistance/tolerance to Striga hermonthica in maize cultivars adapted to western Kenya. A resistant inbred line developed by Maseno University, MSMP1/P2 was crossed to Striga susceptible inbred line 5057. Experimental units comprised of resistant parent P 1 , susceptible parent P 2 , their F 1 and F 2 generations, and BC 1 P 1 and BC 1 P 2 generations. The six generations were evaluated under Striga sick plots at Nyahera during the short rains of 2012 and long rains of 2013. Field evaluation for entries were grown in a randomized complete block design with three replicates. The results showed significant differences among generations for emerged Striga, Striga damage rating and maize growth including Plant and Ear height. Most of the additive, dominance, additive x additive, additive x dominance and dominance x dominance effects were significant indicating the importance of the additive, dominance and epistatic modes of gene actions in controlling emerged Striga, Striga damage rating, plant and ear height. Most components conferring Striga tolerance behaved in a qualitative manner. Dominance effects had higher mean values over additive effects. Significant dominant genetic effects (d) for Striga emergence and Striga damage rating suggested preponderance of non-additive genetic effects in the inheritance of Striga tolerance. The results also reveal the involvement of duplicate epistasis where the dominance estimate and dominance x dominance interaction had opposite signs. The presence of duplicate type of gene interaction confirms the importance of dominance gene effects.

Sesbania sesban was amiable to controlled cross pollination when the emasculation and pollination operations were performed in the morning. A medium of 10% sucrose solution was found to be optimal for in vitro germination of the pollen grains. The pollen is quite tolerant of orthodox storage conditions enabling controlled crosses to be performed among accessions that flower in differing seasons of the year.

Striga hermonthica (Striga) weed is widespread in Kenya, where it causes significant cereal crop losses, particularly when susceptible varieties are grown. The use of maize (Zea mays L.) genotypes that support reduced Striga hermonthica emergence can form an important basis for developing resistant cultivars. The objective of this study was to evaluate the response of diverse maize hybrids to Striga weed infestation and to identify high yielding and stable hybrids. Six experimental maize hybrids and three commercial hybrid checks (DK8031, PhB3253 and H513) were evaluated under Striga and Striga free conditions at Nyahera and Maseno in western Kenya in 2011 and 2012 growing seasons. The data collected included grain yields and other yield components; emerged Striga counts and Striga damage rating (on a scale of 1-5) at 8 and 10 weeks after planting (WAP). Significant differences (P < 0.05) were observed in grain yield and yield components; emerged Striga counts and Striga damage syndrome in both years. Negative correlation (r) was observed between emerged Striga and yield as well as between Striga damage ratings and yield. Maseno experimental hybrids produced much better grain yields and were more stable compared to commercial varieties under Striga infestation and in Striga free fields. Deployment of the tolerant/resistant high yielding well adapted hybrids coupled with other management options such as rotation with legumes and cultural practices could possibly help in depletion of Striga seed bank in the soils in western Kenya. EH12 and EH14 maize hybrids were formally released for commercialization in the Striga endemic areas of western Kenya.

Nutrient enrichment is one of the most serious threats to wetland ecosystems. Information is lacking, particularly concerning the response of wetland plants species in Kenya in regard to nutrient enrichment of wetlands. Understanding the mechanisms and adaptations that allow only certain species to thrive in the potentially stressful wetland environment requires the study of the biology of these plants. This study was carried out to investigate the growth and nutrient uptake among some selected wetland plant species in Lake Victoria basin, Kenya. Seedlings of Cyperas esculentus L., Aframomum angustifolium (Sonn.) and Phragmites australis (Cav.) Trin. Ex Steudel) were grown outdoors in pots. The pots were arranged in a completely randomised design under out-door conditions in the Botanic garden at Maseno University. Plants were provided with four nutrient dosage levels of 0 mg [no fertiliser added], 50 mg, 100 mg, 150 mg fertilizer [N: P: K, 10:26:10] per pot and replicated five times. The plants were irrigated daily with tap water for eight weeks. Data on growth which included shoot height, stem diameter, leaf number per plant, leaf area, leaf width, leaf length, shoot and root weights were determined. Leaf N and P was also determined. The data were analysed by analysis of variance (ANOVA) in SAS statistical package. Nutrient availability treatments significantly (P ≤ 0.05) influenced the growth and biochemical parameters investigated. Cyperas esculentus and A. angustifolium had higher rate of biomass accumulation as evidenced by increase in shoot and root weights compared to P. australis. Root-shoot ratios reduced with increasing nutrient concentration in C. esculentus and A. angustifolium, while that of P. australis increased up to 100mg treatment, then slightly reduced at 150mg treatment. Phragmites australis had significantly higher foliar P and N content than the other two species with increasing nutrient availability. There were significant interactions between nutrient treatments and species in most of the parameters measured. We recommend Phragmites australis as a better agroforestry plant species for reclaiming wetland areas.