At a 2021 IRCL board meeting, the issue of greasy green spot was brought up by Tim Sallin of IMG Citrus. Other growers at that meeting also shared their experience with the problem. Sallin described greasy green as “a relatively new and poorly understood defect that has been increasing substantially over the past five years.” He said greasy green is now “the number one defect resulting in the elimination of fruit.”
At the IRCL board’s request, University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) professor Mark Ritenour approached CRDF about funding for greasy green research.
According to the proposal approved by CRDF, the greasy green defect causes a green cast disfiguring the fruit peel; it is developing more often and earlier in the season in recent years. More than one cause is possible, but one likely culprit is greasy spot rind blotch. Another potential cause is phytotoxicity from pesticide applications. The proposal also states that while the green cast on fruit is a particular fresh fruit problem, a significant increase of greasy spot symptoms on orange leaves has been observed and can lead to defoliation and yield loss.
This study aims to look at why traditional fungicide programs are less effective than before with an emphasis on rind quality. What is learned from this study can guide fungicide programs on all citrus types to better manage greasy spot on orange leaves as well as rind blotch on fresh fruit.
The three-year project began on April 1. Megan Dewdney at the UF/IFAS Citrus Research and Education Center will be the principal investigator. Ritenour and Liliana Cano, both with the UF/IFAS Indian River Research and Education Center, will be collaborators.
“This important three-year study will address the need for combating this disorder so that packouts will increase, thus providing a better grower return and future for our industry,” said IRCL Executive Vice President Doug Bournique.
Source: Indian River Citrus League
Share this Post