KOMAZA is excited to announce a four-year research partnership with the Kenya Forestry Research Institute (KEFRI). We are participating in KEFRI’s nationwide entomology research project to better understand the eucalyptus pest blue gum chalcid (BGC). The project will test mitigation strategies in order to limit the ravaging effects the chalcid wasp has on eucalyptus plantations.

The economic impacts of BGC

Blue gum chalcid, Leptocybe invasa (Hymenoptera: Eulophidae) is a pest that has invaded eucalyptus, stunting tree growth and in some cases causing broad mortality across woodlots. Given that eucalyptus is a significant part of Kenya’s forest cover, with over 90 species present in Kenya, the tree is a vital contributor to the national supply of wood. Some estimate that it contributes about KSH 1 billion to the economy each year. It is critical to protect farmers from the blue gum chalcid, as widespread mortality would cause significant economic losses.

The spread of BGC

The pest originates in Australia and came to Kenya in 2002 by way of Israel, migrating down through northern Africa. It is now causing mortality in woodlots in Kenya, Uganda, and Tanzania – and is expected to continue marching toward South Africa. Within Kenya, the chalcid wasp has affected trees in Nyanza, Western, Central Rift Valley, Eastern, and Coast Provinces. Introduced to the Coast in 2003, the pest spread across most Coastal districts by 2009. KEFRI has been monitoring the spread of BGC attacks along the Coast since 2005.

Ngumbao Karisa (X-farm employee), Eston Mutitu (Senior Entomologist at KEFRI) and Clare Hunt discuss the research trial.

Responses to BGC

Effectively managing BGC is a challenge. Widespread use of chemical controls (such as systemic insecticide Methomyl or Methomex 90SP) is both environmentally unsound and economically unviable. Species diversification is one effective way to reduce the spread and severity of BGC attacks, a step that KOMAZA is embarking on with the introduction of the indigenous Melia volkensii as part of KOMAZA’s evolving farmer package (research continues into other commercially viable tree species).

One of the most effective pest management strategies is a Classical Biological Control (CBC) strategy, which involves the introduction of a biological control agent that is a natural enemy of blue gum chalcid. KEFRI has identified two parasitoids, Quardivasticus mendeli (QM) and Selitrichody koycevv (SK) as potential biological control agents which together have been effectively used against BGC in Israel and elsewhere in East Africa. It is these two parasitoids that KEFRI is evaluating in this “biological control” study.

Trial design details

KEFRI has applied for – and been approved for – governmental permits to import Quardivasticus mendeli (QM) and Selitrichody koycevv (SK) from Israel, first to conduct safety tests and then to be introduced into BGC-infested woodlots in Kenya. These parasitoids have been screened against a number of indigenous trees and plant species similar to eucalyptus to ensure that they will not have unintended effects on the ecosystem.

The trial design involves three plots of 500 eucalyptus trees each, each plot planted with different types of eucalyptus (E. urophylla, GC167, and GC10). KOMAZA’s plots are part of dozens of test plots in three provinces across the country (with at least three test plots per region in Western, Nyanza, and Coast provinces), which will be both pre- and post-release monitoring sites for several years after woodlot planting.

We will collect data on the incidence and severity of blue gum chalcid on the three trial plots. Then, the two parasitoids will be released onto the woodlots and data collection will continue to see whether the incidence and severity of BGC attacks decrease due to the natural predators. Specifically, the research will determine:

1. The population and damage dynamics of BGC in the Coastal region
2. The most effective method of the biological control agent’s release by assessing its establishment and dispersal rates
3. The impact of the parasitoids on reducing the impact incidence and severity of BGC

The team is collecting data on the incidence of BGC on the trial plot trees. To do so we shake the tree leaves over a white sheet and count how many fall out.

BCG are very small - hard to see with the naked eye. The team examines the sheet for any pests.

KOMAZA role in the trial

KOMAZA’s role is to plant and maintain three research plots of eucalyptus, each plot containing a different variety of the tree. KOMAZA will gather data on blue gum chalcid outbreaks. Over time, KOMAZA will help KEFRI analyze the data from various research plots across Kenya to determine the effectiveness of the parasitoids in stemming the spread of BGC. As well, KEFRI hypothesizes that E. urophylla, unlike other types of eucalyptus, is not a host of BCG, and can thus act as a natural buffer to the spread of BGC; therefore the incidence of BGC on E. urophylla will be comparatively analyzed to see if this hypothesis bears out with the data.

KEFRI’s role in the trial

KEFRI’s role is to lead the research trial, which involves:

• Providing technical expertise and necessary equipment
• Conducting site visits several times a year and as necessary if any problems arise
• Analyzing data as part of larger study
• Publishing the summary article in a scientific journal

The research will be conducted over the next four years, and the results of which are expected to be communicated in an academic journal.

Our experimental farm

The joint research is just one trial that KOMAZA is conducting on its experimental farm – the “X-Farm.” KOMAZA is committed to conducting best practice research about our crops – to ensure that they grow as successfully as possible while establishing a net positive environmental impact. We make operational improvements based on our research findings which help us better serve our farmers.

Meaghan Hawes, former Director of Crop Production, watches as Eston Mutitu, Senior Entomologist at KEFRI, signs an MOU to formalize the project with KOMAZA.

I am working at KOMAZA this summer with support from the Brown Starr Fellowship in social entrepreneurship. I’m joined by another Starr Fellow, Danielle Dahan. At Brown (where KOMAZA’s founder got his start), I study geoscience and biology. I came to KOMAZA to learn about the implications of my study on agriculture and about the organization as a whole.

On our first trip to KOMAZA’s experimental farm in Ganze, Danielle and I took a matatu (minibus). Although the roads were unpaved and scattered with potholes, the view of the landscape was beautiful. The lush green hills and crops may have been a poor representation of the generally dry and desert-like area, but the view allowed us to take some amazing photographs, which hardly did it justice.

As we rode toward Ganze, I also noticed changes in soil composition visible from the road. Further from Ganze town, the soil was clay and iron-rich and likely had relatively high water content. As we got closer, the soil lost its red tint and grew more tan and sandy.

Rows of eucalyptus at the X-farm

When we arrived at Ganze, we jumped on some piki pikis (motorcycles) and rode to the X-farm, where we were greeted by a few of the staff who were planting and building new structures for the nurseries. David, one of our colleagues, gave us a tour around the X-farm. It was interesting to see the variations in the different types of eucalyptus trees, some with thick trunks, some with so many branches they looked almost like shrubs.

We also looked at the test crops, jatropha, cowpeas, green grams, and groundnut crops and the role they play on KOMAZA farms. Walking the distance of the X-farm, we noted the huge variation in soil color, texture and likely composition from one area to another. One explanation we discussed is the variation in rain distribution due to topographical changes, but it was interesting to see the drastic changes from one location to another.

Row of GC785 type of eucalyptus on the X-farm

After our tour, we talked to Etemesi, the X-Farm Manager, who confirmed that all the crops on the farm are healthy and growing well. He gave us an introduction to what he does on the shambas (farms) and talked about the construction that is going on. We told him that we wanted to look at the rainwater harvester, so he sent us with Mbao to take a look at the harvester on his shamba.

Ngumbao, a worker at the X-farm, shows us the rainwater harvester constructed to irrigate his crops.

Actually seeing that harvester that we have been reading about was helpful to get a better understanding of scale and its degree of functionality. Ngumbao told us that it was meant to provide water for four shambas, but because of the cracks in the cement, it can only hold enough for one. He seemed excited to hear that our project will include work on new solutions for harvesting rain to irrigate crops.

Lastly, we looked at the compost holes. There wasn’t too much to see except some rotting food and shrubs, but it was useful to see the scale of the composters in relation to the scale of the farm.

Solomon, David, Ngumbao, and Ali Abbas look at a eucalyptus seedling on the way from Ngumbao's shamba.

Overall, the trip to the X-farm was a great opportunity to get a better understanding of what the work at the KOMAZA office is aimed toward, and specifically for Danielle and me, to see the importance of water on the farms. It was really impressive to see how well maintained the crops on the X-farm were, and although we did not see many other shambas on this visit, we hope to return again during our time at KOMAZA.