Early harvesting of rainfed plant cane to prevent heavy infestations of Eldana saccharina (Lepidoptera, Pyralidae) in Ferké Sugarcane plantations, Ivory Coast

Abstract

The African stalk borer Eldana saccharina is an endemic pest of high economic importance in sub-Saharan Africa which often causes heavy infestations in rainfed plant cane subjected to a cycle of 15-17 months. The present study aimed to reduce overall damage due to this borer by early harvesting of sugarcane at three different periods. It involved two experiments carried out in Ferké 1 and Ferké 2 sugar estates over 17 months in rainfed plant cane, following a randomized complete block design (RCBD) with four different treatments. Treatments were composed of three harvesting periods (T1: November 15, T2: December 15, and T3: January 15), and a control (T0, no harvest), all in 4 replicates. The Ferké 1 experiment was planted with the variety N21 on 25/07/2017 and harvested on 23/06/2019. That of Ferké 2 was planted on 15/06/2017 with the variety M2592/93 and harvested on 05/12/2018. The study showed that variety N21 with high fiber content was more tolerant to stem borer than variety M2593/92 credited with a moderate fiber content. Stem borer infestations were significantly reduced across crop cycle following early harvesting on M2593/92, as opposed to N21. Without early harvesting, M2593/92 was much more infested than N21, with respectively 24 and 10% of internodes bored. Data showed that early harvesting in rainfed plant cane could be beneficial in the prevention of heavy infestations due to E saccharina.