Issue link: https://read.dmtmag.com/i/418083
www.goodfruit.com GOOD FRUIT GROWER DECEMBER 2014 69 absorb the calcium. However, for some cultivars, such as Braeburn and Honeycrisp, which are susceptible to calcium-related disorders, there are advantages to beginning applications in July, about four weeks after bloom, Neilsen said. Boron Sandy soils can become boron deficient, and in the 1930s, lack of boron almost wiped out the entire B.C. apple industry, Neilsen said. Trees developed blossom blast, a phenomenon where some of the blos- soms are brown and fail to develop into fruit. Neilsen said it resembles frost damage except that it is erratic. It can also cause surface cracking of the fruit, known as droughtspot, which in the past was mistakenly attributed to water stress. As boron is very mobile and soluble, fertigation is an effective way to boost levels in the tree, though when it's overdone it can lead to boron toxicity, which manifests itself as shoot dieback. Trees don't need much boron. Neilsen recommends a rate of 0.175 gram per tree annually, though different cultivars might have different requirements. Leaf analysis can provide a good measure of the tree's boron status. Zinc Zinc typically is found in low levels in Pacific Northwest soils. Deficiencies can result in tiny leaves on some branches, rosetting (where the tree has a mixture of big and small leaves), and blind buds. In Neilsen's experience, fertigation is not effective in boosting zinc levels, but soil applications of zinc sulfate can be toxic. Zinc precipitates in the soil if the pH level is high, he said. "So we're at the stage of using various dormant sprays and chelated zinc sprays," he said. • /HDYHVRQWUHHVGH¼FLHQWLQPDQJDQHVH KDYHLQVXI¼FLHQWFKORURSK\OODQGWXUQDSDOH JUHHQFRORUEHWZHHQWKHYHLQV PHOTOS COURTESY OF GERRY NEILSEN 6\PSWRPVRIDSRWDVVLXPGH¼FLHQF\LQFOXGHVFRUFKLQJDQGFXUOLQJRIWKHOHDIWLSV =LQFGH¼FLHQWWUHHVPD\KDYHVPDOO SRLQWHGOHDYHVDQGEOLQGZRRGOLNHWKLV 5HG'HOLFLRXVWUHH Food Safety Analysis Water Quality Analysis s &OOD 0ATHOGEN !NALYSIS s /N3ITE 6ERIFICATION 3AMPLING 0ROGRAM s $RINKING 7ATER s 7ASTEWATER $ISCHARGE s 2EGULATORY 2EPORTING !SSISTANCE Serving Agriculture and Industry Since 1978 '3 #ENTER 2OAD 7ENATCHEE 7! 509662 7 !HTANUM 2OAD 5NION 'AP 7! 5094527707 WWW#ASCADEANALYTICALCOM s 1