Understanding Psammophory in <i>Raphanus sativus</i> and <i>Lagenaria siceraria</i>: An Approach to Reduce Herbivory

Abstract

Sand entrapment on plant surfaces, termed psammophory is a widely known
trait of the plants having significance in reducing herbivory and regarded as
one of the potential plants defense phenomena. Trichomes protruding from
the surface of leaves and stems defend plants from many herbivores. These
trichomes of plants often entrap sand on their surfaces or release some
exudates on which sand can get adhered, this phenomenon of carrying sand
on their surfaces is called psammophory. Sand and soil are naturally nonnutritive and most of the herbivores find them difficult to process. The
presence of these substances (soil, sand) increases the plant defense and
reduce herbivory. There is lack of studies for investigating the impact of
psammophory on economic plants including vegetables. The current study
attempts to understand the benefit of the psammophoric properties of soil
and sand in reducing the attacks of herbivores on radish (Raphanus sativus)
and bottle gourd (Lagenaria siceraria). Both of these species suffer a heavy
loss in their yield due to cabbage borer (Hellula undalis Fabr.) and western
striped cucumber beetle (Acalymma vittata), respectively. The current study
examined whether presence of sand on these plant surfaces physically
protected them from herbivores.