Case Study: Using chippers for control of Eldana in sugar cane industries
Eldana (also known as African sugarcane stalkborer) is a significant problem for many sugar cane farmers on our continent and can result in major yield losses if not managed. On the 24 December 2016 +- 2000 tons sugar cane were destroyed by fire in the Upper Tongaat area in KwaZulu-Natal. All sugar mills in the area were closed and there was great concern for the spreading of Eldana. Desperate for a solution, Beaufort farm decided to hire a Tomcat chipper to destroy the stems of sugar, thus eradicating the host for the Eldana, in order to prevent the spread to healthy crops. More about this problematic pest to the sugarcane industry and our success story below…
What is Eldana?
Indigenous to our continent, Eldana is particularly widely distributed in sub-Saharan Africa. Sugarcane is the main crop host of the African sugarcane stalkborer but it will also attack maize (where it is a relatively minor pest), sorghum and rice. It attacks maize plants late in their development when it can affect grain filling which results in yield loss. In the wild its hosts are wild grasses (Poaceae) such as Guinea grass (Panicum maximum), wetland sedges (Cyperaceae) such as papyrus (Cyperus papyrus), rushes (Juncaceae) and typha (Typhaceae). In Eastern Africa, Eldana saccharina is often only a minor pest on maize but is a major pest on sugarcane. Because the pest attacks plants later in their development, infestations affect grain filling which results in yield losses.
Case Study: Results of our Wood Chipper Process
On the 5 January Tomcat proceeded with chipping the burnt sugarcane at Beaufort farm and after 16 days we had completed the task.
Costs involved:
Tomcat Chipper rental at R2000/day
Diesel at 45 litres/day on a straight 7hr shift
5 Laborers feeding the chipper
Diesel cost of tractor pulling the chipper.
Average cost works out at R48/ton.
If compared to hauling and dumping at a average cost of R25/ton it seems cheaper to dump BUT if you take the nutrients that you are putting back into the soil by chipping as well as the suppression of weeds as well as the water retention, you would cut your fertilizer costs in half, therefore making it a very viable option. To fertilize one is looking at approximately R3000/hectare which equates to R37.50/ton at 80tons/hectare. This is then a saving of R13.50/ton if chipping.
The photos below show the regrowth which occurred afterwards.
After three weeks. Chipping versus slashing.
Growth after three weeks. Tomcat chipper used. Notice that the majority of stalks that could host Eldana have been destroyed. The benefits of the mulch are priceless!
Regrowth after three weeks. Cut with a slasher to try and eradicate Eldana. See the amount of stalks remaining.
Regrowth after three weeks. Cut with a slasher to try and eradicate Eldana. See the amount of stalks remaining.
Slasher damage to stalks can cause disease.
We chipped on average 0.8 hectares in a 7hr shift which equates to roughly 65 tons per day through the chipper. This quantity could even be increased through better planning. We also had a study group which was attended by SASRI (The South African Sugarcane Research Institute) and 7 farmers from the area with the general consensus that this could very well be a viable option for the control of Eldana.
SARSI
SASRI is a world renowned agricultural research institute at the forefront of a thriving sugar industry. Research at SASRI is clustered within four multidisciplinary programmes, namely Variety Improvement, Crop Protection, Crop Performance & Management, and Systems Design & Optimisation. An Extension Service provides the essential link between researchers and sugarcane farmers. SASRI also offers a range of services including fertiliser advice, disease diagnoses and education courses.
Traditional methods of detecting and managing Eldana
African sugarcane stalkborer infestations may be detected by walking through young crops looking for characteristic feeding marks on funnel leaves, the presence of dead hearts and holes in tunnelled stems. Samples of affected stems can then cut open to find caterpillars and pupae. African sugarcane stalkborers may be detected in older crops and in crop residues by taking random samples of stems to dissect to find caterpillars and pupae.
Methods of managing this pest include cultural practises (e.g. Intercropping maize with non-hosts crops like cassava or legumes like cowpea can reduce spotted stemborer damage. Or a repellent plant such as silver leaf desmodium (Desmodium uncinatum) and a trap plant, such as Napier grass) can be uses as a “push-pull” method to control the pest), biological control (such as the use of two parasitic wasps, Cotesia flavipes and Xanthopimpla stemmator) and chemical control (applications of granules or dusts to the leaf whorl early in crop growth to kill early larval instars).
It appears that there is now a new highly effective method for dealing with Eldana, namely the use of wood chippers! We are excited to be involved with this unconventional new application of our wood chippers and look forward to seeing how this method can be fine-tuned to become even more effective for farmers in future.