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[compost_tea] Strike Rust



Elaine,
I contacted Bruce Elliot via email re stike rust but as yet I have not had a reply.
You say in your email that there have been  "..excellent results..." using  CT on Wheat in Nebraska to reduce rust disease.
We are going to be using CT this year to reduce Srike Rust in Wheat in Western Australia. We will be using fungal dominated CT. I am assuming that we will require fungal diminated CT to out compete the Srike Rust (being a pathogenic fungus)??
I am also assuming that we will need to cover say 70% of the leaf surface area (same as in  grapes) in order to out compete the Strike Rust. Looking forward to the microscope to assess this!!
As per info below it would seem that coverage of the wheat seedling  is essential (our autumn/early winter) when warmer temps favour infection. Also spring time when things warm up would be another important time to get the CT on the plant. (we grow winter wheat). We will also be spraying CT on to stubbles prior to turning in to get an inoculation of beneficials into the system. 
Are we on the right track??
The following is some info on rust. 

PP589 (revised), July 2002

Marcia McMullen, Plant Pathologist, NDSU Extension Service
Jack Rasmussen, Plant Pathologist, Agricultural Experiment Station

The Disease The following factors must be present for wheat leaf rust infection to occur: viable spores; susceptible or moderately susceptible wheat plants; moisture on the leaves (six to eight hours of dew); and favorable temperatures (60 to 80 degrees Fahrenheit). Relatively cool nights combined with warm days are excellent conditions for disease development.

Under favorable environmental conditions, rust spores germinate and penetrate into the wheat leaf. The fungus obtains nutrients from the wheat leaf, and within a week to 10 days the fungus produces more spores, which erupt through the leaf surface. These newly produced spores are wind-blown to other wheat leaves or fields.

Resistant and susceptible wheats react differently to infection. If a variety is resistant, a reaction develops within the leaf which kills or retards the fungus, and the infection is stopped. Resistant varieties may develop yellowish-white "flecks" at the site of spore penetration (Figure 1). Moderately resistant varieties develop small reddish-orange pustules surrounded by a yellow-white halo (Figure 1). Susceptible varieties do not have the ability to retard fungal growth; the fungus grows extensively and produces relatively large pustules that may produce about 1,000 spores daily, each one of which is capable of reinfecting wheat (Figure 1). The outcome of a 10-day repeating cycle is the formation of many spores during the growing season, and these spores can move great distances on wind currents (Figure 2). Therefore, this disease can increase rapidly and epidemics may occur whenever susceptible varieties are grown and weather conditions are favorable for rust development.

The extent of yield losses caused by leaf rust depends on the severity and duration of infection. The greatest losses occur if the crop is severely rusted from the seedling stage to maturity. .


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