Effectiveness of aluminum-fosetyl in the control of early nutfall of coconut tree due to Phytophthora katsurae (Pythiaceae)

Publication Type:

Journal Article


Agronomie africaine, Volume 15, Number 3, p.123–133 (2009)




Early nut fall and bud rot due to Phytophthora katsurae are the most important diseases of coconut tree observed in recent years at the Assinie plantations of PALMINDUSTRIE Company, Côte d’Ivoire. Field investigations conducted in 1983 revealed a high rate of nut fall (50-70%) during the rainy season. Cutting of coconut stands with rotten buds, as a way to control the spread of Oryctes sp., allowed to assess the number of dead trees over 139 and 89 ha of land for the hybrids and Grand West cultivars, respectively. In addition to those disease control measures proposed by the Company, comparison trials were systematically carried out using 2 fungicides: aluminum-fosetyl [fosetyl] at 3 doses (3.2, 4.8 and 6.4 g of active ingredient/tree) and Ridomil [metalaxyl] at one dose (3.125 g of active ingredient/tree). These fungicide were injected into the stem of the coconut every 3 months starting from December 1984. After 3 years, the efficacy of the 3 doses of aluminium-fosetyl over Ridomil in significantly reducing nut fall, even at low rates (3.2 g of active ingredient/tree), was apparent. However, the technique still remains out of reach of most farmers because of lack of technical know-how. It appears therefore, that an improvement of the technique, so as to make it accessible to the farmers, is a necessity.