Contributed by Jeffrey Wall                           

Figure 3: Chestnut Castanea sativa fruits

Figure 3: Chestnut Castanea sativa fruits

In the fourth century BCE, the Greek traveler Xenophon reported that chestnut was a prominent food for people of the Caucasus (Xenophon [1895]).  The tree and its use as food and timber first spread from this region around the Black Sea and eventually to Central and Western Europe (see Figures 3 and 4). The Caucasus and Eastern Turkey remain the center of highest genetic diversity for the European chestnut, Castanea sativa (Villani et al. 1994).  The onset of chestnut blight, Cryphonectria parasitica, which has been reported in Azerbaijan since 2003, is a threat to this genetic diversity and to the livelihoods of chestnut-cultivating communities in the Caucasus Mountains of Azerbaijan.

In northern Azerbaijan, which is a culturally diverse region, chestnut trees populate a forested region of over 200km2, and support numerous rural communities involved in chestnut cultivation, collection and sale. Today, traditional management of chestnut in Azerbaijan is practiced in dozens of villages in combination with that of hazelnut and walnut over a large highland landscape covering more than 4000 km2 of highly heterogeneous land. A diverse range of management and collection practices can be observed, from multi-cropping, nursery cultivation and grafting, to wild harvesting and the deployment of free-range cattle to distant chestnut forests.

Figure 4: Multiple uses of chestnut-picnic table and food

Figure 4: Multiple uses of chestnut-picnic table and food

Over a period of one year, we organized a series of community meetings in five villages in order to identify strategies to respond to the chestnut blight.  These meetings produced a remarkable consensus.  Villagers agreed that: first, chestnut cultivation should remain the primary land use strategy in their territory, and second, the unique and locally preferred chestnut varieties must remain viable. Further, as a guideline, all participating organizations and research should focus attention on (diqqət) and develop a cure for (dərmon) the chestnut blight.

To draw attention to the chestnut blight, we conducted 22 household questionnaires and extended interviews in two village sites in order to investigate the economic importance of the chestnut to local livelihoods. Results clearly show the importance of chestnut production to household incomes (see Figure 5). Average chestnut sales per household were 2997 AZN (1 AZN ≈ USD 1.2) in 2010, more than the average annual salary of a teacher.

Figure 5: Average sources of total annual household income in communities in northern Azerbaijan (n=22)

Figure 5: Average sources of total annual household income in communities in northern Azerbaijan (n=22)

To find medicine for the chestnut tree, we conducted widespread sampling and characterization of the chestnut blight fungus in Azerbaijan.  This has opened up the possibility of pursuing a biological control technique known as applied hypovirulence.  For European chestnut, applied hypovirulence has been demonstrated to effectively inhibit the spread of chestnut blight within treated and non-treated neighboring trees (Heiniger and Rigling 2009; Hoegger et al. 2003).  Still in pursuit of an effective cure, our next step is to undertake a social impact analysis and then apply hypovirulence in the first-ever trials to biologically control chestnut blight in Azerbaijan.

References