Good Fruit Grower

September 2016

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Page 36 of 55 Good Fruit Grower SEPTEMBER 2016 37 leafhopper samples, with more expected throughout the season. Leafhoppers are of interest because of their eating style. They are a pierc- ing-sucking insect that uses a stylet to puncture plants and probe around for nutrients within the phloem and the xylem. They leave a telltale of their passing: toxic saliva associated with something called hopperburn, a browning around the edge of the leaves caused by the insects' siphoning. "It is also caused by the plant's physiological response to hopper feeding," he said. He also has a number of other suspects for which he has no proof, but based on personal observations they represent possibilities. Bees have been implicated in past research, and Boucher captured 500 bees during bloom. The majority were honey- bees along with one native bee species. Flies and aphids are other possibilities. The ooze that comes out of cankers on a fire blight-infected tree is a mixture of plant sap, fire blight bacteria and a sugar produced by the bacteria. Boucher thinks the sugar may be an attractant to flies. In June, when ooze comes out of the fruitlets, Boucher has seen flies land and remain on the ooze for up to a minute. "When flies land on the margins of the canker's ooze, they could be picking up bacteria for possible transmission," he said. He's caught "lots" of flies on the yellow cards, adding credence to his belief they may be involved, but he hasn't identified the specific culprit yet. Aphids excrete honeydew, which may contain fire blight, and ants eat the hon- eydew because it is nutrient-rich. "If the ants carry infected honeydew away, they could inadvertently transport the patho- gen along with it," Boucher said. That said, he thinks this is a less likely scenario, compared to either bee or hop- per transmission. But as long as aphids continue to appear on the sticky cards, he'll be testing aphids to see if they are involved. • Photos by heather Grab/Cornell University find if they are transmitting fire blight bacteria. The fly sitting on the apple on the right (seen between the two apples) may be there for the sugar produced by the fire blight bacteria. Based on his observations of flies on cankered fruit, Boucher wonders if they're a vector for the disease. 10500 Brentwood Blvd., Brentwood, CA 94513 800.634.1671 or 925.634.2191 (Alison Clegg or Richard Chavez) 877.457.6901 (Henry Sanguinetti) M E M B E R O F w w w . p r o t r e e n u r s e r y. c o m Expertly Crafted from Start to Finish. Apples Aztec Fuji ® (DT-2 cv) Banning Red Fuji (USPP 16,624 P2) Buckeye ® Gala (USPP 10,840) Cosmic Crisp™ (USPP 24,210) EverCrisp ® (cv. 'MAIA 1') PPAF Firestorm™ Honeycrisp Honeycrisp™ (USPP 7197) Lady in Red * (USPP 18,787) Royal Red Honeycrisp ® (USPP 22,244) September Wonder™ Fuji (USPP 11,193) Ultima™ Gala (USPP 13,753 P2) Available on B10 ® , B-118, EMLA, Geneva ® , M-9 T337, NIC -29™, or Pajam #2. ** * Trademark license for Pink Lady ® brand available upon request. Cherries Benton™ Bing Black Tart BlackPearl ® Brooks™ BurgundyPearl ® Chelan™ Coral Champagne Cristalina™ EbonyPearl ® Available on Colt, Gisela ® , Krymsk ® , Mahaleb, or Mazzard. * * ** Not all varieties are available on all rootstocks. Call for specific grafting information. Lapins RadiancePearl ® Rainier Selah™ Skeena™ Sweetheart™ Tamora Tulare™ Vans NEW! NEW! NEW! At ProTree Nursery the growth of our high-quality rootstocks begins in our lab under the watchful eye of Norma Aguilar who has perfected her craft over the past 12 years. As our rootstocks grow and are transplanted outside, they are cared for by Guillermo Montoya, who, with 16 years of experience, knows what it takes to produce only the very best rootstocks that will grow into fruitful trees. Call ProTree today to order benchgrafts for 2018 and dormant-budded trees for 2019. Let our expertise in combining the right rootstocks with the heartiest varieties work for you. Guillermo Montoya ProTree Nursery, LLC Norma Aguilar ProTree Nursery, LLC

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