I am afraid it might be the start of the dreaded new, virulent southern strain of Downy Mildew, which hit hard in the midwest the past few years. I heard that it was brought up by hurricane remnants in 2005 as spores, but I suspect this is mostly urban legend. However it got here, it's bad news, as it seems to be fatal to most cucumbers and melons, and it also attacks squash and pumpkins, but they seem to tolerate it. The key to control is repeated and frequent fungicide applications, and rotation of products to avoid resistance. But, this is hard to do for a homeowner. Michigan State University Cooperative Extension has a lot of information about Downy Mildew -- look under the Vegetables tab.

Agreed. Looks like micronutrients are in order, Trojan. This is a pretty common sight here in our neck of the woods (Orange County, San Diego County, Calif.) due to our long, chilly and wet winter and spring. Many of my citrus looked this way. I spoke with Vince Lazaneo, the Home Horticultural Advisor for the San Diego Master Gardeners about a couple of my citrus, and he also suspected micronutrient deficiency. I use Grow More Citrus Growers Blend, which is an excellent product that provides micronutrients in the correct percentages and concentrations for citrus. I have applied it twice, now to my affected citrus. First time as a foliar spray, and then about 4 weeks later, to the soil, diluted in 2 gallons of water, and then followed up with an additional 2 gallons of acidified water (I use plain old white vinegar, and acidify to 4.5-5.0, use a pH meter, they can be found at any better garden center, and they're cheap insurane). The acidified water will help the tree take up and absorb the micronutrients. And, for your new trees, you will want to fertilize twice a month during the growing season (for us that's about April through November) with a good citrus fertilizer that has micronutrients. Vigoro Citrus & Avocado fertilizer with micronutrients is decent. You really want to find one with a high sulfur micronutrient content, as this will help to acidify our somewhat alkaline soils. You can also use soil sulfur once or twice a year as a top dressing to help out our pH issue. If we we a lot of cold weather, and a lot of rain, that, along with our somewhat alkaline soils will cause a locking out of micronutrients, and your citrus will look like what you're seeing right now. And, as far as amending your soil - I don't recommend that. You're going to create this yummy "hole" that your citrus roots are not going to want to leave. You're better off just digging a hole twice as large as your root ball and backfilling with your native soil. Loosen up the soil, and make sure you don't create slick sides in the hole from your shovel. Fill that hole up with water. Wait 24 hours. If the hole has not drained by then, you have a drainage issue, and in that case, you WILL want to amend with some gypsum. Otherwise, you're good to plant. Backfill with native soil, taking care to water in well to remove any air pockets. Keep the rootball at soil level (unless you're in clay, and then elevate the top of the rootball a few inches). Create a nice large well that extends to at least the drip line (tree canopy). You'll want to extend this well as your canopy grows. Set your drips to drip in the drip line of your well. Then, fill with about 1 to 2" of worm castings, another layer of compost, then top with bark mulch. Be sure to keep all clear of the trunk by a few inches all the way around. Water in well. Then, sprinkle your fertilizer around the well ring at the drip line, and water than in. Paint your trunk and exposed branches with indoor water soluble flat latex house paint diluted in half with water to protect the trunk and branches from sunscald. That's how to plant a fruit tree here in S. California :-) Deep water during the hot summer months 2 times a week, then cut back to once a week in the winter, or no watering at all if we're getting rains. Top dress with soil sulfur once or twice a year. I usually will top dress at the beginning of the growing season in April, when I start fertilizing, and then again, around June or so, when our weather starts to heat up. Remember, NEVER fertilize or apply sulfur to dry trees. Okay, probably more than you wanted to know, but certainly I hope will help your little kumquat green up :-) Patty S. Here is a link that might be useful: UC Davis: The California Backyard Orchard: Citrus

The image is quite small to be certain of anything. Can you please post a larger version? Also, as to the leaf bending, it would help us the most of you also post a picture of that. Thanks.

Ah, excuse me for being blind. =) I was reading more about Septoria, and several sites said something along these lines about identifying Septoria: uniform, small size of the spots (which if you look closely are spore receptacles) and the lack of concentric rings in the spots. The presence of fruiting bodies (the spores) of the fungus, visible as tiny black specks in the centers of the spots, confirms Septoria leaf spot. I can't see any black marks inside the paler areas, not even tiny ones. Also, the marks are not uniform at all. In regards to early blight: The classic symptoms occur on the leaves where circular lesions up to 1/2" in diameter are produced. Within these lesions dark, concentric circles can be seen. This is also not seen on the leaves. The sites said humidity plays a factor in both early blight and septoria, but especially with early blight (warm air and humidity). However, I live in a desert -Utah- where humidity is about negative 60%. Ok, I exaggerate, but being from Florida, this is what it feels like! This seems to rule out early blight, but supposedly septoria can manifest itself in cooler weather with rain (which has happened here the past week on and off). I would be convinced if only it weren't missing those characteristics mentioned earlier. Another site said that septoria is often confused with bacterial spot. Since I am not familiar with these things, maybe one of you could confirm if it may or may not be bacterial spot. I'm wondering because the treatment of a fungus is supposedly different than the treatment of a bacteria.