Abstract:

In this study, we established changes in minimum and maximum temperature over the past 20 years,
and how these changes a r e likely to affect the status of key banana pests and black Sigatoka
disease in main banana cropping systems. A survey was conducted at elevations of 1200, 1400,
1600 and 1800 m above sea level in 13 sites previously used in 1 9 9 2 / 1993. Mean monthly
minimum and maximum temperatures at different elevations were computed between 1991 and 2013
and used to determine the temperature change. Data was collected on weevil damage, nematode
populations and black Sigatoka severity. Changes in weevil damage, nematode population densities and
black Sigatoka severity were determined. Pearson’s correlation analysis was used to establish
relationship between minimum and maximum temperature change, changes in weevil damage, black
Sigatoka severity and nematode population densities at different elevations. Results show that
minimum temperatures in sites above 1400 masl increased by 1°C over the 20 years. Key banana
pests and black Sigatoka disease were observed at elevations where they had not occurred before.
Change in black Sigatoka disease, Rhadopholus similis, Helicotylenchus multicinctus and
Meloidogyne spp. positively correlated with change in both temperature but change in banana weevil’s
damages positively correlated with maximum temperature.