Translocation and distribution of 32P labelled potassium phosphonate in black pepper (Piper nigrum L)

The aim of this project was to study the translocation of potassium phosphonate within black pepper (Piper nigrum L.) and to elucidate the amount of chemical distributed through out the plant based on a tracer technique. Potassium phosphonate is a potential fungicide used against the pathogen Phytophthora capsici, which causes Phytophthora foot rot (Quick wilt) in the plant. Reports indicate that translocation of phosphonate is ambimobile, but there is no visual evidence for this. Potassium phosphonate labelled with radioactive phosphorus, 32P, was applied to the black pepper vine and bush pepper and its translocation to different parts of the pepper plant was studied using an autoradiography technique. The chemical which migrated to different parts of the plant was quantitatively estimated by measuring 32P on a liquid scintillation spectrometer following Cerenkov counting. Only traces of the chemical were lost to the soil through root systems. These results indicate that foliar sprays of potassium phosphonate to pepper could be a viable method of application for soil and foliar pathogens.