I have an established zoysia lawn that has been beautiful for over 30 years. This spring large dead spots appeared on south facing hills and this problem has spread to surrounding areas. Lawn care pros looked at it and treated if for fungus with no samples taken. More than a month later it's getting worse. Online searches say corn meal at 20 lbs per 1000 sq ft will kill many types of fungus. I'm aware that thatch can also be a problem. I need an expert opinion from someone who knows what they're talking about or I'm going to lose the entire yard. I can include pics if I can find a link...or can send by email if anyone can help. Please reply even if not able to help so I can continue to look for answers.