Controlling Peach Rust

 Micobutanil dilution (Gravex) is 6-12 oz/100 gallons. That works out to 0.5 to 0.88 ml per gallon.

Flowering in Florida

 We know that Anna, Dorsett Golden, Tropic Sweet and Ein Shemer will flower in Florida's spring, and we are currently unraveling the mechanisms of dormancy release/ floral control. 

But after that wave of flowers in Jan/Feb, we have other trees that do flower and produce fruit, starting in April. 

In early April, 2025, we had flowering on Reverend Morgan and Sundowner after about 530 chill hours. This was followed in mid-April with flowers on Cauley, Orange Cauley, and Chestnut Crabapple. These have always shown flowering tendencies here in Archer, FL. Some "Shell" specimens continue to flower. Black Strawberry made one set of flowers on a 90 degree bent branch. 

The last week brought flowers on White Winter Pearmain, Wickson Crab, and Winecrisp. 

Today on April 21 there are new flowers on Granny Smith, Mutsu and Arkansas Black. 

Crosses were made with Anna pollen against everything flowering, but the numbers are limited by a few bursts of flowers.  What we do know-

Wickson Crab- not self fertile

Rev morgan - self fertile

Granny Smith - not self fertile / self fertile, depending on the website you check

Cauley - self fertile

Orange Cauley- assuming self fertile

Shell - self fertile

Winecrisp - Not self fertile

Cripps Red (Sundowner) - Not self fertile

All crosses were performed close to 'popcorn' stage and flowers were emasculated, even in non-self-fertile varieties.  'Anna' was used as the pollen parent. 

Dormant Sprays

 Dormant sprays are vital in controlling pests and pathogens on fruit trees.  However, every year I go to to them, I have to dig through the internet to find precise amounts of copper and dormant oil to apply. The sheets attached to most crop protection products fall off or get crusty, so it is good to indpendently verify the mixtures. Plus, most applications are listed in terms of "tablespoons" or percents of stock solutions without listing the concentrations. 

To fix the problem, I'll list it here. 

for those that prefer the archaic, imprecise and problematic methods of measurement

Dormant Oil (mineral oil)  2% v/v  Stock 100%.  2.56 oz per gallon. 

Copper (diammonia diacetate complex) stock 27% (w/v) 4-5 tsp/gallon. 

For those that prefer the elegance of the metric system

Dormant Oil (mineral oil)  2% v/v  Stock 100%.  20 ml / liter

Copper (diammonia diacetate complex) stock 27% (w/v) 18.75 ml/liter 

Florida Apple Project

 This resource is long overdue, but for a good reason. I have worked with fruit tree growers for over two decades and have grown a variety of fruit trees on my space for the last 7. Over the last few years I have gained a lot of insight into what works and what doen't and have resisted the urge to prematurely post anything that could lead to bad decisions and lost investments, based on my lousy information.

I'm Kevin Folta, I'm a Professor at the University of Florida that has examined the genetics and genomics of agriculturally important traits in fruit crops, mostly strawberry. 2012 I took on a leadership position that led to the university hiring someone else to work closely with the strawberry breeding program.  When my leadership term ended, I had the opportunity to look at the world around me and find a new place to invest my curiousity and heavy research toolbox. 

At the same time COVID hit and I found the time to expand irrigation on our small farm. My wife farms fruits, vegetables and livestock on 18 acres outside of Gainesville, FL. We sell at two farmers markets every week. 

Currently I grow a suite of fruit trees that provide seasonal fruit for farmers markets.  I grow multible varieties of mulberry, citrus, peaches, plums pears, feijoa, jujube, avocado, banana, persimmons and then also, apple. 

Apple was the last thing I expected to grow.  Everything I read and heard is that these disease magnets are difficult to work with, require too much management and protection, then die from nematodes. Efforts by Prof Ralph Sharpe adn Dr. Wayne Sherman at the University of Florida throughout the 1950s-1990s also suggested that efforts in apple were not commercially viable. As a guy with enough work to do, that's a reason to not grow them. 

But in 2018 I was speaking with a retired USDA inspector who told me about apple trees in the area, including some that produced 400 lbs / year. From a farmers market perspective, my interest was piqued. 

So I began planting the usual standbys on the typical rootstocks suggested for sandy, awful soil, M111. I assembled a nice collection of genotypes thought to be 'low chill' based on online accounts. I had noticed that the chill hour designation was not always applicable with pears, as anything I planted seemed to grow, flower and fruit just fine. 

In 2021 I had a significant number of trees in the ground on M111. I then crossed paths with Javier Rivera, who was growing apples near Orlando.  We took up frequent conversations, and he introduced me to a rootstock he had been using with some success, Geneva890. He also grew on others, including the BUD series. I started planting on G890 as well.  

Within a year I learned of others growing Honeycrisp outside of Tampa. Another had orchards far south near Lake Okechobee and also in southern Georgia. I found weird materials from folks across the American South and added them to my collection. 

While I didn't plan to do research on low chill apples, the patterns observed and the potential for small farms was intriguing.  After working with flowering in strawberry and teaching principles of chilling, this was an attractive areas of study. 

That's the stepping off point.  My plan is periodic updates here that describe facets of the project.  I'm not going to post frequently and will refrain from preliminary observations without clear indications that they are not recommendations. 

Here we go. This just might work.