Grower records and logistic regression to solve production problems in highbush blueberry

Abstract

Blueberry plants displaying abnormal fruit development in the form of splitting and equatorial russeting were reported from 15 farms in Atlantic and Burlington Counties, NJ, in the spring of 2017. The cause was unknown; however, phytotoxicity due to a chemical application was suspected. Grower application records were used to unravel the cause. A total of 237 records were received, of which 110 were from fields displaying injury. A logistic regression analysis identified pendimethalin as the primary cause, although soil type did show a probability greater than 1. Other incriminated herbicides were frequent tank mix partners with pendimethalin and not responsible for injury. The methodology described is helpful for identifying explanatory factors among a complex set of possible or likely causative elements. In this case pendimethalin was identified as the cause of blueberry phytotoxicity.