Thanks, John ! Actually, leaf spot....either the fugal (most common, here) or bacterial....really doesn't seem to hurt the plants...other than, of course, robbing them of leaf surface . That , of course "robs" the plant, and probably does impede growth....and LOOKS bad, but, what you DON'T want is what I DO have ! There are several plant diseases that, when you read up on "cures", or prevention", usually start out by saying, "dispose of infected plants". I always 'read" that as saying, 'you're screwed'
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There are several forms of "botrytis" , each using a different plant as it's favorite "host" (most do target 'root crops").., as well as several forms of the erwinia bacteria, again, each seems to like different 'plant part". Sad to say, most of the information I have read, and most of the people I've talked to (extension agents, farmers, greenhouse operators, etc.) agree that both pathogens are present , in the soil, almost everywhere, but usually in small enough concentrations that they don't pose a serious threat.....UNTIL "something" happens to put stress on the plant, which lowers it's ability to protect itself against them, so, really all I can do is keep my nose to the wheel,and keep trying different forms of action......solarization is the next thing I'm going to try......until I hit on smething that brings my loss % down to something that's bearable
. Thanks again for your concern !