New LI6400XT leaf photosynthesis meter AfricaRice

The LI6400XT of LI-COR is an advanced leaf photosynthesis meter. AfricaRice has purchased this equipment for use in the Parasite project. It will enable us to get a better understanding of host‐parasite interactions (of parasitic weeds in rain-fed rice) as affected by present and future environmental conditions. Parasitic weeds extract nutrients, water and plant metabolites from their host and they alter the host plant hormone balance, primarily ABA levels which in turn affects host plant photosynthesis and hence production of metabolites. The effects of parasitic weeds on the host are therefore to a large extent measurable at the leaf level by assessing the plant physiological performance, i.e. the leaf photosynthesis system. The LI6400 XT will enable us to measure such effects of parasitic weeds on the host plant, and moreover, to measure these under variable environmental conditions. We will vary the environmental conditions by changing the water and/or nutrient status of the growth medium and measure photosynthesis and chlorophyll content under these different conditions and compare infected and uninfected rice. Moreover, the photosynthesis equipment enables us to measure the effects of different (and fully controlled) levels of CO2, temperature and light intensity on the parasite-host interactions, which obviously enables us to enhance our understanding on host‐parasite interactions for parasitic weed species and rain‐fed rice as affected by present and future environmental conditions.

The Centre for Crop Systems Analysis (CSA), of Wageningen University has the same system (LI6400 XT) which enables us to do comparative measurements in Wageningen and Dar es Salaam.