Oil palm

Abstract

Oil palm is the highest oil-yielding perennial crop, which produces palm oil and palm kernel oil, being used for cooking and industrial purposes. The palm oil is extracted from the mesocarp of sessile drupe fruit, which contains around 50 % oil. Palm oil is derived from the fleshy mesocarp of the fruit, which contains about 45–55 % of oil. The yield of oil palm varies with genotype, management and environmental factors. Water and fertilizer management holds the key factors in successful management of the crop. The important environmental factors that influence yield are temperature, vapour pressure deficit, relative humidity and rainfall. Breeding for drought and salinity tolerance along with dwarfness and higher oil yield are the key traits for oil palm improvement. As water is the critical factor for successful growth of oil palm, any deficit will act as a signal for repression of female sex expression leading to the production of a large number of male flowers coupled with slow growth leading to poor productivity. Hence a thorough understanding of the morphological, physiological and biochemical basis for drought tolerance is vital for the successful growth of the crop. Drought tolerance phenomenon is complex, since it involves varied mechanisms, which are often antagonistic to each other. These different factors lead to a balance that enables the plant to withstand water stress to varying degrees. Under the Indian context, agronomic techniques for achieving better water reserves at plantation level (through irrigation and erosion control), ensuring more effective distribution of available water to oil palm (by reducing competition with weeds, bare soil cropping, antitranspirants, cropping with other palms) and lessening water consumption of palms during dry seasons through ablation of bunches are effective, but become limited due to technical or economic reasons. The new research options should primarily concentrate on the knowledge of responses of adult oil palm and seedlings under water stress. The research on drought tolerance should integrate factors like photosynthetic capacity, assimilate partitioning (source–sink relationship), stomatal regulation and resistance or rigidity of cell membrane integrity in the seedlings and field stages for the same planting materials in order to develop performance tests. The research on the above aspects should lead to new strategies for developing planting materials more closely adapted to the respective agroclimatic conditions.