Green gram (Vigna radiata (L.) is the hardiest of all pulses and is well adapted to Arid and Semi-Arid Areas (ASALs). However, the high light intensities, temperatures and erratic rainfall experienced in these areas lead to high evapo-transpiration rates leaving very little water available for plant use, thus negatively affecting growth and yield parameters. This study was conducted to evaluate the effect of reduced light intensity on agronomic performance of four high yielding green gram accessions (GBK-022494A, GBK-022501A, GBK-022502A and Nylon-1). The study was carried out at Kiboko in Makueni County, Kenya during the 2012 short and 2013 long rain seasons. A Shade net used in this study reduces light intensity by 35 percent. The experiment was laid out in

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Sweet potato (Ipomea batatas [L.] Lam.) is an economically important crop in East Africa chiefly grown by small holder farmers. Sharing of vines for planting is a very common occurrence among these farmers and eventually varieties are given local names, making it hard to trace the original pedigree. It is therefore important to characterise the sweet potato germplasm for purposes of breeding and germplasm conservation. In this study, 68 sweet potato accessions were evaluated for diversity using 12 microsatellite markers. The genetic relationship of the germplasm was evaluated using the Jaccard's coefficient for dissimilarity analysis, unweighted pair group method with arithmetic means (UPGMA) tree and principal component analysis (PCoA) on DARwin software, while summary statistics was done using PowerMarker and Popgene softwares. The polymorphic information content of the markers ranged from 0.1046 for markers J67b and J67 to 0.3671 for marker J1809a, with a mean value of 0.2723. The total number of alleles amplified was 21. The major allele frequency ranged from 0.5882 for marker JB1809a to 0.9412 for markers J67b and J67c. Cluster analysis divided the accessions into four major clusters. Principle component analysis divided the accession into four groups which were different from those by cluster analysis. This study was able to identify several distinct accessions as well as a few possible duplicate accessions that overlapped on the cluster analysis.

Sweet potato (Ipomoea batatas L.) is one of the most widely grown root crops worldwide. In Africa, it is grown in small plots by poorer farmers. Production of the crop is extremely low in Kenya as compared to other African countries due to the existence of common insect pests. Sweet potato weevil (Cylas spp.) is known as the biggest pit fall for production and productivity of the crop in the country. This study sought to determine the opinion of sweet potato farmers concerning sweet potato resistance to Cylas spp. and determine control strategies employed by sweet potato farmers in managing the pest. The study also sought to determine the sweet potato production constraints faced by the farmers in Homa Bay County, Kenya. The study was conducted using a Participatory Rural Appraisal approach in which 269 farmers in the County were interviewed on the sweet potato varieties with field resistance to Cylas spp., the crops' production constraints (with emphasis on damage by Cylas spp.) and farmers' control strategies in regard to the weevil. Data were also collected from the farmers whose sample size was determined using the table on sample size selection and standardization equation. Data were analysed using descriptive statistical techniques that were frequencies, percentages and standard errors. The study established that majority of the farmers from Rachuonyo (89.7%) and Ndhiwa (91.9%) were not aware of any variety that had field resistance to Cylas spp. However, 10.5% of the farmers in Rachuonyo and 8.1% of the farmers in Ndhiwa identified nine varieties which have shown relative field resistance to root damage by Cylas spp. The varieties that were identified to be resistant to Cylas spp. by farmers in Rachuonyo were Kalamb Nyerere, Tombra, Sinia, Odinga, Kemb 10, Wera and Zapallo. However, the varieties that were identified to be resistant to Cylas spp. by farmers in Ndhiwa were Amina, Mugande and Ndege Oyiejo. Further, the findings revealed that Cylas spp. was the most problematic pest by 90.3% and 96.8% of households in Rachuonyo and Ndhiwa, respectively. Majority (64.5%) of the farmers in Ndhiwa did not use any methods to manage Cylas spp. However, farmers in Rachuonyo (26.2%) and Ndhiwa (15.3%) preferred re-ridging during weeding as a management strategy in regard to Cylas spp. These findings reiterate the importance of the sweet potato weevil in rural sweet potato farming systems and thus innovative management strategies are necessary.

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