Seed Borne Fungal and Bacteria Pathogens Associated with Farmer-Stored Sorghum Seeds from Eastern, Coast and Nyanza Regions in Kenya

Sorghum (Sorghum bicolor (L.) Moench) is an important cereal crop in Kenya. Access to good quality seeds is one of the constraints facing the small scale farmers in key areas growing sorghum. Good quality seed is an important factor for maintaining plant population and increasing crop yield to attain food security. One of the important aspects of good seed, besides high germination and purity is the absence of seed borne pathogens. In the present study, an experiment was carried out to identify fungal and bacterial pathogens associated with farmer-stored seeds of sorghum. The seeds were collected from farmers in Nyanza, Coast and Eastern regions, Kenya. The seeds were washed with sterile distilled water and sterilized in 1% Sodium hypochloride for 5 minutes, rinsed with sterile distilled water and dried using a blotting paper. The dried seeds were placed onto prepared Potato Dextrose Agar (PDA) and macerated seeds streaked on nutrient Agar (NA) on sterile Petri dishes and incubated at 23±20C. The growing pathogens were sub-cultured on new media to make pure cultures. A segment of mycelia from the sporulating colonies in each pure culture was examined under a compound microscope and identified based on their morphology, colour and mycelia growth characteristics for fungi while bacterial identification was done using colony color and morphology on nutrient agar and biochemical tests. Ten fungal pathogens and one bacterium were identified growing on the sorghum seed samples. These were Acremonium spp., Alternaria spp., Aspergilus niger, Bipolaris cookie, Collectotrichum graminicola, Fusarium moniliforme, Fusarium solani, Fusarium ventrichosum, Phythium aphanidermatum, Rhizoctonia spp. and a bacterium Xanthomonas spp.  It was observed that majority (32%) of the seed samples from Coast region were infected with bacteria Xanthomonas spp. Phythium. aphanidermatum was the most prevalent fungal pathogen detected on seed samples from Nyanza region with about 20% prevalence. Results showed that majority of the seed samples from all the regions were contaminated with various pathogens. This study highlights the need to create awareness to farmers on the use of proper production practices, storage facilities and conditions to improve the quality of stored sorghum seeds. Keywords: farmer-stored seeds, seed-borne pathogens, sorghum DOI: 10.7176/JBAH/10-18-06 Publication date:September 30th 202

Genetic variability of sorghum landraces from lower Eastern Kenya based on simple sequence repeats (SSRs) markers

The aim of this study was to estimate the genetic variability of sorghum landraces grown in lower eastern Kenya based on simple sequence repeats (SSRs) markers. A total of 44 landraces obtained from the farmers and four improved varieties were analyzed using 20 SSR markers. All markers were polymorphic with polymorphism information content (PIC) value ranging from 0.04 to 0.81 with a mean of 0.49. Heterozygosity ranged from 0.00 to 0.04 suggesting that each detected a single genetic locus and that each of the sorghum accession used was stable. The alleles ranged between 2 and 10 and an average of 5.05 alleles per primer pair. The gene diversity ranged from 0.04 to 0.83 with a mean value of 0.53. All possible allele combinations ranged from 2 to 10, while major allele frequency ranged from 0.32 to 0.98. Genetic distances varied from 0.15 to 0.90 with two genotypes Karuge 1 and Karuge 2 obtained from Kiritiri in Mbeere having the minimum (0.15) and indication of very close relatedness. The diversity of the landraces was structured more on geographical locations and on seed colorations than agroecological conditions. Such intraregional genetic proximity in sorghum landraces would arise through seed exchanges among farmers. Analysis of molecular variation indicated higher variation within populations than among the groups. The genetic diversity can be exploited in hybridization programs to improve sorghum varieties grown by farmers in semi arid areas.Key words: Genetic variability, landraces, simple sequence repeats, sorghum

Knowledge and Information Systems on Sorghum Amongst Sorghum Farmers in Nyanza, Eastern and Coastal Regions, Kenya

As climate change continues to impact negatively on crop productivity, hardy crops such as sorghum could end severe food insecurity due to their potential to withstand adverse conditions. Farmers rely on localized indigenous knowledge passed on by word of mouth, informal training systems and growing practices as farmers interact. Though there are many stakeholders in sorghum production and its value chain, access to information and knowledge by farmers is still limited especially in marginalized regions. To understand information and knowledge management systems in sorghum production and how stakeholders interact a study was conducted in Eastern, Nyanza and Coastal regions of Kenya using structured questionnaires. The results showed most farmers were females. Majority had attained primary and secondary education, while 7.5% had no education. Farmer-to-farmer source of information on where to source seed was highest compared to agricultural extension officers and media advertisement. 60% do not consult where to get seed, instead use on farm saved seeds. Majority use traditional knowledge through experience compared to sources such as ministry of Agriculture, trainings and fellow farmers. Farmer-to-farmer information network and market analysis was commonly used on where to sell the grain. On-farm saved seed was selected based on size and color and about 60% conduct germination test on the seed from whichever source before planting. Majority (82.5%) use on-farm saved seeds, manure/compost and cultural methods to control pests.  Of the respondents, 15% (eastern) and 7.5% (coastal) reported they have no measures to respond to climate change. Majority use grain for human consumption and about 73.1% are not members of any farmer group. Therefore, sensitization on benefits of sorghum crop, formation of more active farmer groups, involvement of agricultural related stakeholders, provision of more support and capacity building could enable them attain optimum agricultural productivity. Keywords: drought, food security, information, knowledge, sorghum, stakeholders DOI: 10.7176/JESD/14-4-05 Publication date: February 28th 2023