Rice yields under Rhamphicarpa fistulosa-infested field conditions, and variety selection criteria for resistance and tolerance

Rodenburg J., Cissoko M., Dieng I., Kayeke J., Bastiaans L.

The present paper, published in Field Crops Research, reports on the existence of resistance and tolerance against Rhamphicarpa fistulosa as well as on yield levels and relative yield losses incurred under R. fistulosa infested field conditions among a range of adapted lowland rice varieties.

The facultative parasitic weed Rhamphicarpa fistulosa, is a widespread problem in rain-fed rice production systems in Africa. Little is known about rice varietal differences in infection level and yields in fields infested by this root hemi-parasite. During three cropping seasons (2012–2014), an experiment was conducted to address these knowledge gaps and to identify suitable variety selection criteria for R. fistulosa resistance and tolerance. Sixty-four adapted lowland rice varieties, including all interspecific lowland varieties of NERICAs, their most common parents – IR64 and TOG5681 – and two locally popular varieties – Mwangulu and Supa India – were grown in an R. fistulosa-infested field in southern Tanzania. 

The study facilitated identification of thirteen varieties with high resistance, sixteen varieties with low parasite-inflicted yield losses and two varieties with high tolerance. These varieties would be invaluable for future rice breeding programs. For farmers in R. fistulosa-endemic areas the most promising varieties are probably NERICA-L-40 and -31, as they combine good yields under infested conditions with low levels of parasite infection.