Complementary study of boron absorption by coffee leaves using the neutron-capture-radiography method.

Young coffee plants were treated by putting a droplet of a solution containing 10B-enriched boron on some of their leaves. The rate of boron absorption by leaves (measured using neutron capture radiography) was found to be in the range of 1.9 to 5.3 nmol boron per h. This means that it requires several days for a coffee leaf to absorb most of the boron supplied by foliar spray in the usual agronomic treatments. Technically, the use of the method of neutron capture radiography has revealed to be quite sensitive and applicable to liquid micro-samples (a few microL in volume) even with the low-intensity neutron fluxes available in Costa Rica.