We devote this Podcaster to updates from all of the N2Africa PhDs. Some of the candidates started their studies during the first phase of N2Africa and are close to completion. Others just started their research last September and are still setting up their initial experiments and finalizing their proposals. The topics range from molecular studies with rhizobium to field agronomy, adoption studies and nutrition. We felt it was time for the next generation of nitrogen fixation researchers to share some of the excitement of their findings with you.

Beans nodulate promiscuously with rhizobia. The lack of specificity may be advantageous in certain circumstances but it generally poses a challenge to attempts to successfully inoculate beans. The inoculant strain, when applied, has to compete with indigenous strains for root infection sites and outcomes are dependent on numerous variables.

Aliyu Anchau, Abdullahi enrolled for his PhD studies in February, 2013 on the above topic. Arachis hypogaea L. root nodules were initially sampled from uninoculated plants in over ninety (90) farmers’ fields from the Northern Guinea and Sudan savannas of Nigeria during the 2013/2014 growing season. Thirty two (32) rhizobia strains were successfully isolated from the root nodules, authenticated and tested for effectiveness in glasshouse experiments under axenic N-free conditions.

Amaral Machaculeha Chibeba started his N2Africa PhD project in August 2012 at Londrina State University in Brazil.

Mazvita Chiduwa is pursuing her studies for a PhD at Murdoch University. She commenced in July 2012 under the supervision of Ravi Tiwari, John Howieson, Julie Ardley, Graham O’Hara and Paul Mapfumo.

This research is on cowpea (Vigna unguiculata, (L.)) which is an annual leguminous crop indigenous to Tropical Africa. Women farmers mostly grow cowpea as a food security crop and it is an important source of protein and income for many of them. The high protein content of cowpea, its adaptability to different types of soils, drought tolerance, ability to improve soil fertility and prevention of soil erosion makes it an important economic crop. In Africa, the women farmers produce, process and sell snacks made from this nutritious legume.

Intensification of common bean (Phaseolus vulgaris L.) cultivation on smallholder farms in the Northern Highlands of Tanzania is the main focus of my PhD study. This study is prompted by the low yields (0.3 – 1 t ha^-1) obtained by smallholder farmers, despite the large prospective productivity of improved varieties of common bean (3 t ha^-1) in Tanzania. The study aims to unravel the contributions of genetic, management and environment related factors to common bean yield and nitrogen fixation.

Esther Ronner is research assistant employed by N2Africa at Wageningen University and is conducting her PhD studies within the project.

Objective:

To screen effective, competitive and host broad spectrum of common bean and chickpea rhizobia for use in African soils.

Main activities:

I am Ojo Comfort Tinuade, one of the N2Africa PhD rstudents with Wageningen University and a Research Fellow with International Institute of Tropical Agriculture, Ibadan. My research interest is to explore the potential benefits of rhizobia inoculation with cowpea. My research activities includes estimating the population density of indigenous rhizobia in soil samples collected from Northern Nigeria, isolation and identification of highly competitive and efficient rhizobia strains from Nigerian soils.