Page 94 - Ecuador's Banana Sector under Climate Change

ecuador’s banana sector under climate change: an economic and biophysical assessment to promote a sustainable and climate-compatible strategy
This second approach to projecting the response of BS to average climate change (Figure 21) indicates that there probably will be little change in the dynamic of BS seasonally. Since the rainfall distribution is not projected to change and this second calculation is based on wetness parametres, the disease will continue to be highly problematic during the rainy season and much less aggressive from around week 24 in the year.
Bringing together three sources of information on BS epidemiology and management, the following implications tentatively can be proposed. The period
of year when BS is the most difficult to manage will remain the same - primarily during the rainy season. The disease may become more aggressive as the velocity of growth of the germination tube of the spores is projected to increase due to a temperature response. This will only occur, however, in the presence of leaf wetness. A final factor can also be proposed in terms of management. The frequency of fungicide spraying is linked to the protection of each new emerging leaf. The leaf, when it first emerges, is an excellent trap for BS spores which later lead to infection under appropriate conditions. If leaf emission increases as has been projected, then more frequent fungicide applications may result to protect the new leaves.
2.3.2 Banana weevil
Phenology models for insects, based on temperature, are important analytical tools for predicting, evaluating and understanding the dynamics of populations
in ecosystems under a variety of environmental conditions. These tools recently have been used for phytosanitary risk assessment additionally. They complement conventional research because they are a less costly option and require lower demand of time and space.
There is scant research on climate change impact on the insect pests of banana and plantain. C. sordidus is a key insect-pest that constrains banana and plantain production. It is very sensitive to temperature change and it could
Figure 21
3000 2500 2000 1500 1000
500 0
State of BS evolution, based on precipitation and evapo-transpiration for Pichilingue
EE4H 2070
EE4H 2050
EE4 H2030
EE4H CURRENT
EE4H m. fijiensis
Week
2 4 6 8 10121416182022242628303234363840424446485052
Source: Authors’ own elaboration, using downscaled weather data from MarkSim weather generator
78