Parasitic interference of sandal (Santalum album Linn.) on common agricultural crops from the homesteads

Abstract

Experiments were conducted at College of Forestry. Kerala Agricultural University. Vellanikkara. Thrissur during 1995-96 to elucidate the various aspects of parasitisation behaviour of sandal (Santalum album Linn.). Parasitisation behaviour of sandal on selected agricultural crops occurring in the homesteads of Kerala. response of selected sandal-host combinations to manures and fertilizers and uptake and translocation of nutrients and photosynthates by sandal-host associations were the principal aspects investigated. Pot culture experiments involving a number of hosts like coconut, cashew, banana, black pepper, jack, mango, rubber, casuarina, erythrina and redgram were conducted as part of the study. The results indicated that, growth parameters of the sandal seedling like total dry weight and number of haustoria varied significantly depending on the host associated with sandal. Maximum growth of sandal was observed in association with the host - Casuarina equisetifolia. No significant decrease was observed in the growth of any of the hosts consequent to the parasitisation by sandal. Host is the principal factor governing the growth of sandal and fertilizer levels tried in this experiment had not caused any significant influence on the growth of sandal seedlings. In, view of the favourable influences by the host complex of a good and bad host together ie., casuarina + erythrina, on sandal's growth, the possible competitive/complementary effects of multiple host combinations on sandal's growth, need be investigated in greater detail.

Sandal plants can take up elements like calcium, sulphur and phosphorus directly from soil and a small fraction of these are also obtained from host. Carbon compounds also are translocated between sandal and hosts. The same host differed in its ability to supply different elements to sandal ie., in the supply of phosphorus to sandal casuarina was better while carbon compounds were optimally supplied by erythrina. So instead of providing a single host to sandal, a variety of good hosts should be provided in the field for ensuring a more optimal growth of sandal. Anatomical studies showed that, sandal roots can establish direct vascular connections with host roots through haustoria.