Morpho-physiological monitoring of oil palms (Elaeis guineensis Jacq.) affected by spear rots (PC).

Abstract

The morphology, growth and physiology of oil palms (Elaeis guineensis Jacq., Deli x Nigeria variety) was characterized at different stages of development of the condition known as ‘dry spear’ or FS (for ‘flecha seca’ in Spanish), and some morpho-physiological indicators associated with a predisposition for the disorder were identified. In Costa Rica, ‘FS’ has symptomology very similar to spear rot or PC (pudrición del cogollo), as it was described in South America. ‘PC’ is a dynamic disorder of complex etiology that affects the development and physiology of palms. The symptomology (‘yellowing’, drying and rotting/) occurs in young leaves and in tissues near the meristem. The aerial symptoms are associated with a deteriorated fine root system. During the initial stages of the disorder in the season with the least precipitation (3.8-73 mm/month), the palms presented low water potential in the leaves, increases in stomatic conductance, reduction in foliage temperature, higher chlorophyll content and reduction of vegetative development. The loss of the fine root system was possibly the cause of the interruption of hormonal ‘signals’ toward the aerial part; which caused the loss of stomatic control of transpiration that led to a hydric, nutritional and energetic imbalance. The anomalous behavior of stomatic conductance and other variables (root density and petiole cross-section), described in a previous article (this journal), is an indicator that could signal conditions of predisposition to a syndrome like PC.