The apple growers on the bus were baffled by it. After negotiating a tough backup turn on a driveway over a deep ditch, we drove past large deteriorating buildings that once housed chickens and livestock, then came to a stop in an abandoned bunker silo.
From there, it was a half-mile walk to what we came to see. (Of course, we’re in Europe, so we did our walking in meters, not miles.)
We were on a farm in the Po River Valley south of Verona in Italy. As we found later, this was ground that Paulweber Benno had rented for the year to grow apple tree stock for GRIBA Baumschule, the nursery of South Tyrol.
The nursery wants to avoid disease, especially fire blight but also replant diseases, so each year its crop is grown on virgin ground by its contract growers. A fire blight outbreak would lead to destruction of all the current year’s production on the site. Fumigation is not used in Italy, another reason for annual movement.
It cost Benno $1,800 an acre to rent the land.
All that was explained to us by Gunther Mahlknecht, who oversees tree production for GRIBA, the cooperative that produces two million trees a year. The Verona area is wet, flat, cash crop and livestock land, with much of it in all-year vegetable production under hoop houses.
About half of the 2.2 million trees produced each year—especially the best ones—will go a hundred miles north to the Alpine apple growing area of South Tyrol. GRIBA is owned by 14 producer-owned cooperatives there. The rest go across Europe and into export.
Cornell University pomologist Dr. Terence Robinson, who acted as guide on the International Fruit Tree Association tour in November, used the occasion on the bus ride after the visit to comment on the quality grading system Mahlknecht had described.
“I kind of beat up on nursery people,” Robinson said. “I think they need to produce better trees. But growers need to demand higher quality trees, and be willing to pay for them. You saw the GRIBA system. We need to do that in the United States.”
Given the demand for trees, and the short supply, growers may want to go easy on that for now, but Robinson has been hammering the point for some time: You can’t afford to use your expensive orchard system to grow trees an extra year before they produce.
The GRIBA grading system sorts trees into four classes: 3+, 5+, 7+, and 7+ Extra, with knip boom trees in the top class.
The lowest quality trees sell for about $3 to $3.50 each and have only three or four branches, less than 8 inches long. Better trees have more and longer feathers and cost progressively more, about $5.75 each for trees with 10 or 11 branches higher than 24 inches above the ground.
Knip boom trees, which are headed instead of being dug at the end of the first year and are grown a second year in the nursery, cost more than $8 each. When royalties are added, a grower could pay 10 or 11 euros ($12.50 to $13.75) for a tree.
To get trees of this quality, the nursery uses intensive management.
Trees grow a foot apart in three-foot rows and are trickle irrigated. Nitrogen fertilizer (about 80 pounds per acre) is applied every other day through the water lines, along with iron to combat the high pH soil. The trees are sprayed weekly with insecticides, and foliar applications of manganese, magnesium, and zinc are made.
The key to feathered trees is multiple treatments with the growth regulator 6-BA (6-benzyladenine, or MaxCel) starting when the trees are two feet high.
Herbicides are used every two or three weeks. No mechanical weed control is used, so they use pendimethalin (Prowl) and glyphosate. Paraquat is no longer used in Europe.
Trees were still fully foliated in mid-November, so before they are dug they are defoliated with chelated copper and sulfur sprays.
More and more European growers are wanting bi-axis trees, but GRIBA does not grow them.
“They are a disaster in the nursery,” Mahlknecht said.
Growers want the two stems to be of equal vigor. This leads to a lot of unsalable trees, which have to be corrected by removing one of the leaders to get back to a single leader tree.
Growers, since they are short on land, are planting trees more and more into an established orchard infrastructure. Posts, wires, and hail nets stay in place and new trees are planted in the same row. While European soils seem to have fewer replant problems, the nurseries are looking to replant disease resistant rootstocks. Almost every tree grown in Italy is on M.9 337 rootstock.
Hail storms are frequent occurrences across the Italian growing areas. “We buy hail insurance to try to help ourselves,” Mahlknecht said.
As a co-op owned by growers, GRIBA has a stake in making the growers who buy their trees successful.
Besides producing apple, cherry, and pear trees of excellent quality, GRIBA works as a consultant in the planning, installation, and management of orchards, not only in Italy but internationally.
GRIBA engineers work with growers in India and Russia installing orchards using their nursery stock. •