TGL NEWS

Thursday
Feb232012

Fungus Attacks Impatiens 

Downy Mildew is a fairly new fungal disease attacking Florida's top landscape flower, Impatiens (Walleriana). Younger plants or new growth will show the first symptoms of leaves looking yellowish or spotted, as if they've experienced extreme cold or a nutritional deficiency. As the disease progresses there will be a whitish growth (spores) on the undersides of the leaves. Then leaves and flowers will drop, leaving mostly stems. 

The scarest part is that this entire process can happen within a few days time!  The below pictured plants went  from looking thirsty, to dropping all blooms within days. 

Before Downy Mildew         

There is really no known cure. Once the white spores are seen with the above symptoms, it is best to just remove the plants.  Experts warn that chemical treatments are expensive and do not really cure. So your best strategy is to quickly remove and dispose of plants that are affected to save any other susceptible plants near by.

Sadly, most local nuseries have decided they will not be carying the Impatiens next year, although the hybrids, New Guinea and sunPatiens do not seem to be susceptible to the disease.  The main seed producers and growers are researching ways to prevent it in the future.

Thursday
Feb232012

Rugose Spiraling Whitefly 

This is a NEW type of whitefly sucking the life from trees, palms and shrubs throughout South Florida.  A tiny, winged leaf-sucking insect with"needle-like" mouths, (not the same as the ficus whitefly) draining all the nutrients from host plants; of Central American origin and found in Miami-Dade County 3yrs ago.

 Injecting Treatment 
Our first encounter was in Miramar at a shopping center we maintain. We first noticed them on Gumbo-Limbo then Callophyllum trees and in a week began infesting the entire property of over 450 trees!  We inquired about systemic treatments with our affiliate New Leaf Pest Control, but realized this whitefly was still very unknown, so we saught expert help from Dr. Catharine Mannion, a University of Florida Associate Professor and Extension Specialist based in Homestead. 

 Preparing for Injections

Dr. Mannion agreed to meet onsite along with the property owners, also inviting the City of Miramar (for adjoining infested trees). She shared her knowledge and assisted with a treatment plan.  She cautioned on the importance of not destroying the whitefly's natural predators from misuse or overuse of insecticides.  

 

The most noticeable symptoms of an infestation of this whitefly is the abundance of the white, waxy material covering the leaves. Like similar insects, these whiteflies will produce "honeydew", a sugary substance, which causes the growth of sooty mold.  Below you can see a picture of Callophyllum tree leaves covered in honeydew.

 

Rugose Whitefly

   

Click here to download more information from University of Florida.