Differences in the effects of temperature and photoperiod on progress to flowering among diverse Mucuna spp.

The use of Mucuna spp. in cover crop and green manure technologies is provi ng to be successful in the tropics and subtropics following intensive effor ts in technology transfer to farmers by NGOs (Non-Governmental Organization s). This includes the transfer of seeds of Mucuna spp, for which the range of adaptation and the effect of environment on crop phenology are poorly un derstood. A selection of Mucuna spp. germplasm was evaluated over a range o f contrasting photothermal conditions in controlled-environment glasshouses . Dates of emergence and first flowering were recorded. Where possible, tri ple-plane rate of development models were fitted to the first flowering dat a to quantify the relative sensitivity of each species to photoperiod and t emperature. All accessions showed short-day responses but there were substa ntial differences in the sensitivity of rate of progress to first flowering to environment, particularly to photoperiod. This results in differences i n maturity period between accessions which, with appropriate understanding, could be functionally exploited by NGOs and NARS. However, if ignored, it could result in the promotion and use of accessions ill adapted to the envi ronment in which they are tested. In consequence there might be unnecessary resistance from farmers to the adoption of green manure and cover crops te chnologies which are vital to the design and maintenance of sustainable far ming systems in low-income countries in the tropics.