Maize weevil (Sitophilus zeamais Motschulsky) is a major maize (Zea mays L.) storage insect pest in the tropics which reduces the quantity and quality of maize hence facilitating establishment of aflatoxin and other mycotoxins. The objective of this study was to evaluate maize weevil resistance on selected inbred lines. Twenty eight inbred lines with 2 checks (MTPO701-reistant and Duma 41-susceptible) were used in this experiment. Thirty unsexed adult insects were introduced into 250 ml glass jars with grains of the lines at room temperature. Evaluation of weevil damage was done at 10, 60 and 120 days after maize weevil infestation. Each category of storage period was replicated 4 times and experiment was set at the same time. Data was collected on percent weevil damage, grain weight loss and number of live and dead weevils on each inbred line. ANOVA analysis showed significant differences (P ≤ 0.05) on weight loss. The selection of the resistant genotypes was based on percent weight loss after 60 days. Resistant lines selected included KEN2/TZL2.25# and LEPOOL-1/TZL2-2-1. These lines showed resistance to maize weevil damage and hence can be stored up to 4 months. At 120 days there was maximum damage and most lines could not be differentiated on the basis of resistance. KEN2/TZL2-2-5# showed consistency in resistance to maize weevils at all storage periods. High heritability at 60 days showed that selection for weevil resistance in these inbred lines is effective and feasible. Results in this study also revealed high, positive and significant correlation relationship between percent damage, weight loss and live weevils. The maize weevil resistant lines can be used to improve resistance of high yielding varieties in breeding programmes.

Azolla tissue contains 5% N, which is slowly released into the soil upon decomposition. Timing of incorporation is therefore important for maximum benefit to a crop. The effect of time to incorporate Azolla biomass on growth and yield of rice was investigated in Mwea-Kenya. Treatments consisted of 7.5 t ha-1 Azolla biomass applied at transplanting, 7.5 t ha-1 Azolla applied at 21 days after transplanting (DAT) and 30 kg N ha-1 inorganic N applied in splits at O, 21 and at 55 DAT. There were control treatments without Azolla and without inorganic N application. The treatments were laid out in a Randomized Complete Block Design (RCBD) with three replications. Phosphorus and potassium were applied at 50 Kg ha-1 each as P 2 O 5 and K 2 O. Plant height and tiller numbers were recorded at 21 (rooting/tillering), 32 (tillering), 42 (maximum tillering), 60 (flowering) and 75 DAT (heading) while yield parameters were determined at physiological maturity (120 DAT). Data were analysed using SAS software and means separated using the least significant difference test (p≤0.05). Azolla incorporation at transplanting significantly enhanced panicle m-2 , grain weight and grain yield while incorporating it at 21 DAT only significantly enhanced panicle m-2. Higher environmental temperatures enhanced Azolla effect. The effect of Inorganic N significantly increased plant height, tiller number, grain weight and spikelets panicle-1. However, percentage grain filling was reduced. The effect of interaction between Azolla application and inorganic N was significant on spikelets panicle-1 and grain weight. Observations therefore indicate that the effect of Azolla on yield and yield components was more when incorporated at transplanting.

Flowering is critical in plant ecology. Through flowering, plants evolve into new plant species that are better adapted to environmental variations. Cenchrus ciliaris is an important forage grass in Kenya, which is drought tolerant but is increasingly becoming depleted in grazing areas requiring reseeding. To identify suitable germplasm for such initiatives, collections from varied ecologies were evaluated at Kiboko to assess any adaptive morphological traits, particularly flowering related, that they may have been acquired in their evolution. Significant variation in days to start flowering (DSF) and days to full flowering (DFF) were observed between sites of ecotype origin and among the ecotypes. Ecotypes collected from Kilifi flowered significantly earlier than those from Kiboko while one Magadi ecotype, MGD3, was late flowering despite being collected from an arid zone. DSF was negatively correlated (p≤.0.001) to percent fertile tillers and the number of inflorescence per plant. Inflorescence length was positively correlated (p≤0.05) to the number of spikelets per inflorescence but negatively correlated (p≤0.001) to the percent fertile tillers. There was a trade-off between plant size and period to flowering where early flowering ecotypes were smaller in size and vice versa. However, a unique ecotype that defied the trade-off, MGD1 from arid agro-ecological zone VI, with both early flowering and robust traits was identified. Findings from Magadi collections indicate that collections from special niches may not be applied as wide area adaptations, especially with regard to drought tolerance. The early flowering trait of some of the ecotypes matched results from various studies involving a wide range of crops other than grasses. The findings of the study provide opportunities for further selection and breeding work.