The Western Chestnut

Dennis Fulbright, professor of Plant Pathology, Michigan State University, recently completed a five month chestnut research sabbatical to Italy. He shares his experiences in this chestnut-oriented culture in this "travel log" article, including information about the integration of the nut into local foods and festivals and cultivation and production challenges. Don’t miss part 3 of the story in the Oct. Western Chestnut issue!

About a week after we arrived, we were taken to the Alpine research center in Pieve Tesino in the foothills of the Alps about an hour outside of Trento where Andrea was teaching a field mycology course (mostly mushrooms). Everyday for a week we went mushroom collecting in the hills filling baskets and for me, re-learning how to identify and classify them. We ate most of the mushrooms collected and every night, for a week, Andrea’s students took turns fixing dinner for the staff, Jane and me. At the end of the week, on Saturday we went hiking to the 9,000- foot peak called Cimi d’Asta. Andrea and I frequently stopped and held up the walk photographing and discussing diseases of the trees along the path; spruce and fir rusts, armillaria root rot, known and unknown canker diseases and many more.

The back of our flat in Viterbo with laundry out drying.

Officially, I had come to Italy to learn more about chestnut, including chestnut culture, chestnut processing and marketing and chestnut blight. Anything I learned about chestnut nut diseases, insects and other pests of chestnut would be icing on the cake. I was also interested in other tree diseases especially Phytophthora root rot and the identification of Phytophthora isolates. Andrea had done a lot of work on the native oak forests in Italy and the causes of their slow and steady decline. There was a lot to do and see in a short 5 months. Not too long after coming back to Viterbo from the Alps, we returned to them, passing through them on our way to a conference in Freising, Germany near Munich. I also had the opportunity to visit the field sites where Andrea is screening observing the progress of Phytophthora root rot as it kills 200- year-old chestnut trees on the sides of hills and mountains. He is using very sophisticated technology on the mountainsides and in the air in fly-bys over these ancient forests. One comment he told me before I came home was that he had data suggesting a perfect correlation between the number of roads on the mountains and the amount of Phytophthora root rot; the more roads on a hillside the more Phythopthora infections could be found there. It was sad seeing trees that had fought off chestnut blight succumb to the strangulation of Phytophthora cambiovora. When the trees die from root rot, no sprouts appear so the hillside looks rather bare until new vegetation begins to grow.

Typical orchard where old stumps are allowed to sprout. The sprout is grafted to maronni variety.

Viterbo is about 60 miles north of Rome. It is near the Cimini Mountains, the rim of an extinct volcano. The small range of hills has an elevation as high as 3,000 feet and has its own climate. It can be foggy up on the hill and it can even snow. Our flat was in the medieval quarter of the town of about 100,00 people, which appears as it did in the 1200’s. As far as we could see were ancient buildings, the defensive wall or landscapes sloping to the Mediterranean Sea in the distance.

The local Cimini Mountains are home to beech, oak, chestnut and hazelnut forests and many of the chestnut and hazelnut forests function as orchards. A hillside covered with chestnut can be utilized in two ways and almost always is. One way is to let the wild Castanea sativa (European chestnut) trees grow for about 17 years and then cut them down and use them as rot resistant poles, much like we, in the states, use pressure treated lumber. The poles are used as fence posts, utility poles and terracing. Small wood mills cut the trees, which may attain 10 to 12 inch diameters during this 17-year growth period. After the previous clear cut, the stumps are allowed to send up new sprouts. These are managed until, at some point, all but three sprouts are eliminated and the three stems per stump are left to grow. With a well-established, large root system pushing them, the remaining three stems grow fast and straight. More to come in the fall issue!