Issue link: https://read.dmtmag.com/i/178281
rather than one. Trees grow vigorously in the Po Valley in Italy, where Musacchi was based, and one of the objectives was to reduce tree vigor by dividing growth between the two leaders. Compared with a spindle, the biaxis tree has twice as many branches, which are half as long. Typically, the biaxis tree has more fruit buds. However, the technique used to develop biaxis trees—using a double graft with two chip buds at the same height on the rootstock—has been patented by Mazzoni Group Nurseries and trademarked as Bibaum. This has prevented other nurseries from supplying those types of trees. An alternative is to plant a standard nursery tree in the orchard, and cut it back to leave only two branches that will grow into the leaders. It takes one more year to develop the tree this way. The biaxis system was conceived for pears as a way to reduce tree vigor in the absence of a dwarfing rootstock, but in Italy, it has been more successful for apples. In both apple and pear trees, branches are renewed periodically by cutting them back, leaving two lateral buds that will grow into new shoots. If a tree has 25 to 30 branches, about three or four can be renewed each year. Musacchi said the major pear variety grown in Italy, Abbé Fétel, is not the best match for the biaxis system. The variety is acrotonic; that is, it tends to put on vegetative growth at the top of the tree, rather than the lower part. Bottom branches get old and develop poor flower buds, therefore the fruit tends to be small. However, he thinks the biaxis system could be a great match for Washington's major pear variety, d'Anjou, which produces ample flower buds on old wood. "Each variety is a different story, and I am strongly convinced that for d'Anjou the biaxis can be a nice solution combined with the rootstocks that are available now, such as [Old Home x Farmingdale] 87 or 97," he said. think the perception of the consumer is that pears seem like an old species," he said. "In Italy, we made a study, and we realized that consumption of pears is very low in young guys under 30, and it's the first choice for people over 55. I am frustrated about this situation. If you don't learn to eat pears when you're young, I am not sure you will eat pears when you're old." New pear varieties would not compete with the old ones, he said, but would be niche varieties that could expand consumption of pears. Italian releases In Italy, Musacchi bred new pear varieties and is planning to bring four of his releases into the United States through National Clean Plant Network's q uarantine program at Prosser, Washington—a process that will take at least three years. The varieties are being tested in Italy for fireblight resistance, which would be desirable because antibiotics cannot be used to control the disease in Europe. In his program he also had selections that were resistant to psylla, a major insect pest in pears. • Rootstocks Growers in Italy use semivigorous quince rootstocks, which are reputedly not hardy enough to endure Pacific Northwest winters. Musacchi said there can also be problems with scion incompatibility, though the Polish quince selections, S1 and S3, would be worth testing. "If they can survive a winter in Poland, I assume they can survive a winter here," he said. In the long term, however, he thinks dwarfing pear rootstocks will be the key to updating the industry. At the University of Bologna, Musacchi ran a pear rootstock breeding program and selected 34 dwarfing genotypes that have the potential to induce early bearing and high productivity without sacrificing fruit size. Thirteen of them are already in in vitro propagation, and he is trying to introduce those genotypes into Washington State. Musacchi also sees a need to update varieties. "For sure, the pear industry needs worldwide innovation because I www.goodfruit.com The Kershaw family, owners of Domex Superfresh Growers ®, are farmers who for five generations have built a business based on shared values, trustworthiness and fiscal responsibility. Our marketing experience and consumer connections fuel the success of the "Superfresh" growers we serve. Call us today to learn more about growing with Superfresh Growers®. We know what's trending NOW. Our difference makes all the difference™ 151 Low Rd., Yakima, WA. 98908 | superfreshgrowers.com Good Fruit Grower OCTOBER 2013 15