Soybean farm-saved seed viability and vigor as influenced by agro-ecological conditions of Meru South Sub-County, Kenya

Objective: The experiment was conducted with the aim of assessing the soybean farm-saved seed viability and vigor as influenced by agro-ecological conditions of Meru South Sub-County, Kenya.Methodology and results: Within one month of harvest, soybean farm-saved-seed was randomly sampled from 30 households in February 2013 from areas representative of agro-ecological zones Upper Midlands II (Ann. Mean temp. (18.2-20.60C); Upper Midlands III (19.2-20.60C; Lower Midlands III (20.9-22.90C) and Lower Midlands IV (21-240C). Standard germination, electrical conductivity and moisture content tests were done according to ISTA rules (2007). Analysis of Variance was done using SAS (9.2) and means separated using LSD. Results revealed that seed moisture was lowest in the warmer LM4 (6.3%) than in the cooler LM3 (8%); UM3 (8.4%) and UM2 (10%). In addition, soybean seed from the cooler agro-ecologies - UM2 (94%), UM3 (86.6%) and LM3 (99.5%) had significantly higher germination than seed from the lower warmer LM4 (57%). Similarly, seed vigor was highest in the cooler UM2 (41.7 C/cm/g), UM3 (45.8C/cm/g) and LM3 (31.6C/cm/g) as shown by reduced seed leachates; indicative of better integrity of seed membranes than seed from the warmer LM4 (79.1C/cm/g). In addition, there was a strong negative correlation between electrical conductivity and germination, showing a faster deterioration due to leakage of electrolytes.Conclusions and applications of findings: The soybean farm-saved seed germination and vigor were significantly influenced by agro-ecological conditions. Considering that seed moisture content in the lower warmer agro-ecologies was significantly lower than those from higher cooler agro-ecologies the observed seed deterioration was attributable to the higher temperatures characteristic of lower altitudes agro-ecologies. Therefore, since the farm saved seed viability and vigor was better retained in the cooler higher agroecological zones (UM2, UM3 and LM3) of Meru South Sub-County, farmers should source better quality soybean seed from these areas. The results validate the need for ecological zoning of suitable areas for the production of high quality soybean seed in Kenya.Keywords: soybean farm-saved seed, agro-ecological zones, seed germination and vigo

Critical analysis of tillage practices with fertility levels in maize and populations in beans as adaptation measures to climate change to enhance food security at Kabete

Trials were carried out in 2012/2013 short and 2013 long seasons at Kabete site representing a warm and wet environment in Kenya to determine, the appropriateness of combining fertilizer levels for maize and population levels with tied ridges for beans, as adaptation measures under changing climate. The maize experiment consisted of three fertilizer levels of 0, 20 and 40 kg/ha N while the bean experiment had three spacings of 12, 15 and 20 cm in a split plot design. The experiments were replicated thrice and consisted of conventional tillage and tied ridges as main plots representing the two soil water management practices while the three soil fertility levels (in maize N0, N20 and N40) or spacing options (12, 15 and 20cm) were sub plots in a Completely Randomized Block Design. The ridges were tied at intervals of 1 m and spaced at recommended crop spacings (i.e. 75cm for maize and 45cm for beans) and the crop planted on the slope of the ridge in 6 by 5 m plots. Basal phosphate (P205) fertilizer in the form of Triple Superphosphate was applied at planting time at the rate of 40kg/ha. Nitrogen in the form of Calcium Ammonium Nitrate was applied at 20 Kg/ha in the 20 and 40 N treatments at planting and further 20kg/ha N top dressed in the 40 treatment level. Harvesting was done at physiological maturity of grain which was air dried. Statistical analysis was done of the treatments and comparisons done of the adaptation advantages of the treatments. Tied ridging increased maize yields at the medium fertilizer level of 20 (+5.22%) but were negative under both zero (-15.56%) and 40 kg/ha application of fertilizers (-5.42%). In the short season, increased bean spacing from 12 to 20 decreased yields under normal (-13.6%) and tied ridges (-37.3%) but remained higher at populations of 12 and 15. In the long season increasing bean population from spacing of 12 cm to 20 had no advantage and under tied ridging compared to normal tillage. Tied ridging as a climate change adaptive measure should not be instituted as a blanket recommendation across rainfall regimes, crops, fertilization levels or plant populations and is more advantageous in drier seasons

An intensive, active surveillance reveals continuous invasion and high diversity of rhinovirus in households

We report on infection patterns in 5 households (78 participants) delineating the natural history of human rhinovirus (HRV). Nasopharyngeal collections were obtained every 3–4 days irrespective of symptoms, over a 6-month period, with molecular screening for HRV and typing by sequencing VP4/VP2 junction. Overall, 311/3468 (8.9%) collections were HRV positive: 256 were classified into 3 species: 104 (40.6%) HRV-A; 14 (5.5%) HRV-B, and 138 (53.9%) HRV-C. Twenty-six known HRV types (13 HRV-A, 3 HRV-B, and 10 HRV-C) were identified (A75, C1, and C35 being most frequent). We observed continuous invasion and temporal clustering of HRV types in households (range 5–13 over 6 months). Intrahousehold transmission was independent of clinical status but influenced by age. Most (89.0%) of HRV infection episodes were limited to <14 days. Individual repeat infections were frequent (range 1–7 over 6 months), decreasing with age, and almost invariably heterotypic, indicative of lasting type-specific immunity and low cross-type protection

Evaluation of personal protection afforded by repellent-treated sandals against mosquito bites in south-eastern Tanzania

Outdoor and early evening mosquito biting needs to be addressed if malaria elimination is to be achieved. While indoor-targeted interventions, such as insecticide-treated nets and indoor residual spraying, remain essential, complementary approaches that tackle persisting outdoor transmission are urgently required to maximize the impact. Major malaria vectors principally bite human hosts around the feet and ankles. Consequently, this study investigated whether sandals treated with efficacious spatial repellents can protect against outdoor biting mosquitoes. Sandals affixed with hessian bands measuring 48 cm treated with 0.06 g, 0.10 g and 0.15 g of transfluthrin were tested in large cage semi-field and full field experiments. Sandals affixed with hessian bands measuring 240 cm and treated with 0.10 g and 0.15 g of transfluthrin were also tested semi field experiments. Human landing catches (HLC) were used to assess reduction in biting exposure by comparing proportions of mosquitoes landing on volunteers wearing treated and untreated sandals. Sandals were tested against insectary reared Anopheles arabiensis mosquitoes in semi-field experiments and against wild mosquito species in rural Tanzania. In semi-field tests, sandals fitted with hessian bands measuring 48 cm and treated with 0.15 g, 0.10 g and 0.06 g transfluthrin reduced mosquito landings by 45.9%, (95% confidence interval (C.I.) 28-59%), 61.1% (48-71%), and 25.9% (9-40%), respectively compared to untreated sandals. Sandals fitted with hessian bands measuring 240 cm and treated with 0.15 g and 0.10 g transfluthrin reduced mosquito landings by 59% (43-71%) and 64% (48-74%), respectively. In field experiments, sandals fitted with hessian bands measuring 48 cm and treated with 0.15 g transfluthrin reduced mosquito landings by 70% (60-76%) against Anopheles gambiae sensu lato, and 66.0% (59-71%) against all mosquito species combined. Transfluthrin-treated sandals conferred significant protection against mosquito bites in semi-field and field settings. Further evaluation is recommended for this tool as a potential complementary intervention against malaria. This intervention could be particularly useful for protecting against outdoor exposure to mosquito bites. Additional studies are necessary to optimize treatment techniques and substrates, establish safety profiles and determine epidemiological impact in different settings

Co-management of Lake Victoria Fisheries

This research article published by Springer Nature Switzerland AG., 2017There have been concerns about the declining fish catches and fisheries ecosystem health for a number of fisheries including Lake Victoria. Consequently, a co-management system has been introduced as a means of, among others, reversing the declining catches. It is hypothesized that non-involvement of fishers in the management of the lake’s fisheries is a major reason for the ever-decreasing catches. This chapter discusses this particular management regime and its application in the lake’s fisheries. The analysis is based on data collected by the Fisheries Division since co-management was introduced in the lake in 1998. The chapter traces the lake’s fishery management since the pre-colonial to the post-colonial period. It presents the aim and rationale for managing the lake’s fishery, the structure of the management and roles of governors. It also analyses trends in illegal fishing practices as well as enforcement performance. The argument here is that co-management has helped in bringing on board fishers and this has enabled laws and regulations to be implemented in a much better way than they were under a central-command system. The chapter subsequently concludes that the involvement of fishing communities in the management of fisheries has created a forum for the exchange of ideas, knowledge and experience on the resources. This strategy has made the communities understand the importance of compliance to the law and regulations and effective management measures

Good immune restitution but unsatisfactory viral suppression in children on ART in a remote Western Kenya area

Mexico AIDS Conference 200

Detection of infectious disease outbreaks in twenty-two fragile states, 2000-2010: a systematic review.

Fragile states are home to a sixth of the world's population, and their populations are particularly vulnerable to infectious disease outbreaks. Timely surveillance and control are essential to minimise the impact of these outbreaks, but little evidence is published about the effectiveness of existing surveillance systems. We did a systematic review of the circumstances (mode) of detection of outbreaks occurring in 22 fragile states in the decade 2000-2010 (i.e. all states consistently meeting fragility criteria during the timeframe of the review), as well as time lags from onset to detection of these outbreaks, and from detection to further events in their timeline. The aim of this review was to enhance the evidence base for implementing infectious disease surveillance in these complex, resource-constrained settings, and to assess the relative importance of different routes whereby outbreak detection occurs.We identified 61 reports concerning 38 outbreaks. Twenty of these were detected by existing surveillance systems, but 10 detections occurred following formal notifications by participating health facilities rather than data analysis. A further 15 outbreaks were detected by informal notifications, including rumours.There were long delays from onset to detection (median 29 days) and from detection to further events (investigation, confirmation, declaration, control). Existing surveillance systems yielded the shortest detection delays when linked to reduced barriers to health care and frequent analysis and reporting of incidence data.Epidemic surveillance and control appear to be insufficiently timely in fragile states, and need to be strengthened. Greater reliance on formal and informal notifications is warranted. Outbreak reports should be more standardised and enable monitoring of surveillance systems' effectiveness

Adapting Agriculture to Climate Change: An Evaluation of Yield Potential of Maize, Sorghum, Common Bean and Pigeon Pea Varieties in a Very Cool-Wet Region of Nyandarua County, Central Kenya

Three experiments were conducted to evaluate the performance of maize, sorghum, common bean and pigeon pea varieties under different water management in a cool and wet region of Central Kenya, as a part of the studies at analogue sites. The first experiment evaluated the growth and performance of three varieties (early maturing: EM, medium maturing: MM and late maturing: LM) of maize (Zea mays L), sorghum (Sorghum bicolor L.), pigeon pea (Cajanus cajan) and common bean (Phaseolus vulgaris L.). The second experiment evaluated maize and sorghum response to water conservation and three fertiliser rates (0, 20 and 40 kg N/ha). The third experiment assessed the effect of water conservation measures on crop yields of common bean and pigeon pea grown under three plant densities (low, medium and high). Tied ridge tillage was used as the water conservation measure and disc plough as the control in the second and third experiments. Maize, sorghum, pigeon pea and common bean took more than 180, 245, 217 and 95 days respectively, to reach physiological maturity. The MM maize variety (DK8031), EM pigeon pea variety (ICPL 84091) and LM common bean variety (GLP 24) yielded the greatest grain of 4,938, 881 and 620 kg/ha respectively, among the respective crop varieties. The sorghum varieties were attacked by fungal and rust diseases leading to yield losses in all seasons. Soil water conservation in general did not have a significant effect on crop yield though there were yield improvements. In the plant density trial, the medium plant densities of pigeon pea (33,333 pl/ha) and common bean (148,148 pl/ha) resulted in the greatest grain yields. The highest grain yield of maize (4,184 kg/ha) and sorghum (47 kg/ha) was obtained in plots with 20 kg/ha of nitrogen fertilizer. Based on the results of this study, pigeon pea and common bean can be introduced in the farming systems to improve crop diversity. The production of the tested sorghum varieties should be discouraged in this region because they are prone to fungal and rust diseases due to the cold and wet weather conditions

Adapting agriculture to climate change - An evaluation of yield potential of maize, sorghum, common bean and pigeon pea varieties in a very cool-wet region of Nayandarua County

Soil and water conservation, use of more adaptive crop genotypes and crop diversification are widely accepted as some of the management practices that can help reduce agriculture vulnerability to impacts of climate change. A study was conducted to evaluate the yield potential of maize, sorghum, common bean and pigeon pea varieties under different water management, plant densities and fertility levels in Nyahururu, Central Kenya. The study involved three experiments. The first experiment evaluated the growth and performance of three varieties (early maturing, medium maturing and late maturing) of maize, sorghum, pigeon pea and common bean. The experimental design was a completely randomized block design (RCBD) replicated three times. The second experiment evaluated maize and sorghum yield response to water conservation and three fertiliser rates (0, 20 and 40 kg N/ha). The third experiment assessed the effect of water conservation measures on crop yields of common bean and pigeon pea grown under three plant densities (low, medium and high). Tied ridge tillage was used as the water conservation measure and disc plough as the control in the second and third experiments. Results showed that water conservation in general did not have a significant effect on crop yield though they were improved. The medium density pigeon pea gave the highest grain (719 kg/ha) followed by low (688 kg/ha) and high plant density (687 kg/ha), though not significant at 0.95 confidence level. Similar trends were observed with common bean grain and dry matter yield. Tied ridges tended to lower maize yield compared to flat tillage while it increased sorghum yields but the difference was insignificant. When average across the tillage systems, the highest maize grain (5553 kg/ha) and dry matter (14298 kg/ha) yield was obtained in plots without N fertilizer. Sorghum dry matter was highest (11333 kg/ha) in plots with 40 kg N/ha and lowest (7903 kg/ha) in plots with 20 kg/ha N. In the variety experiment, the EM pigeon pea variety (ICPL 84091) yielded the greatest grain (881 kg/ha) while the late maturing variety (ICEAP 00040) gave the least (565 kg/ha). The LM maize variety (DK8031) yielded the highest grain (5701 kg/ha) and dry matter (18843 kg/ha). The LM sorghum variety (Macia) had 47% and 49% dry matter yield advantage over MM (Kari Mtama 1) and EM (Gadam) varieties, respectively. The yields for common bean varieties tended to vary with seasons. So what are the conclusions