Not too much rain. This plant has had yellowing of the leaves since it was a seedling. I have gotten a few messages from people that the Golden Midget just has yellowish leaves. I can propose that maybe the fruit turning yellow/falling off is because of lack of pollination? I have a blacktail mountain watermelon growing right next to it that has no problems.

I agree with moroseaz even though my location is in the east - the minute it got a lot cooler I started noticing a distinctive yellowing - I think it's when the veins are green but the leaf yellows. Sure enough, research on the Internet indicated that in heavy clay soils like mine roots can have a problem with iron uptake, and suggested adding iron chelate (of course it being the end of the season you can't find any in the stores). I used to add iron chelate each spring, guess I will have to go back to it. It doesn't seem to be lethal but for me tells me I need to do some amending of the soil - wasn't a problem when the temps were warmer, and it was only some of my plants - Abe Lincoln for one. I'm generally leery of diagnosing plants beyond the basics, but in this case my leaves were very distinctive.

cjsm, thank you so much for the follow-up. I am hearing rather conflicting messages from different people though - my local nursery people told me to keep on watering, since this is a new tree and the root system is not well-developed yet. On the other hand, I hear what you are saying and the overwatering theory in clay soil (which I also have) definitely makes sense! I think I am going to stop watering it for a few days and see what happens. You know, it's hard when you see the leaves drooping in the strong afternoon sun and still not water it! At least it is getting cooler around here these days... BTW, cjsm, my tree was planted in a big planting hole on a slope, and I had plenty of cow manure and things amending the local clay soil, so I think I don't need to take it out to raise it more. I hope this does the trick! Thank you again for your info.

A magnesium (Mg) deficiency would present across the entire foliage mass because Mg is a nutrient that is considered mobile in the plant. As such, it can be borrowed from other organs to supply what is needed for new growth. A zinc (Zn) deficiency, because it is considered immobile in the plant, must be present in the nutrient stream at adequate levels at all times. If it isn't, deficiencies show only in new leaves that grew after the Zn became deficient. Generally speaking, when a deficiency of the mobile nutrients (N, P, K, Mg) occurs, it is seen in all foliage, even though roots are first affected. The rest of the nutrients which are absorbed via the root pathway are considered to be immobile or mostly immobile (can't be 'borrowed' to provide the building blocks for new growth). A simple analogy would be, leaves and fruit are having a tug of war to see which one gets the lion's share of food and nutrients. Since we know the pull of unripened fruit is always stronger than foliage (fruit is a more powerful energy sink than leaves), fruit will win every time. When fruit ripens, it's loses it's pulling power, which frees up food and nutrients that allow the leaves to recover to their normal color. I'm not sure what you meant by, "That happens when the trees aren't getting enough potassium and open". FWIW, most hobby growers end up shooting themselves in the foot when they think they have identified 'a nutritional deficiency' and move to treat it by adding an element or compound aimed specifically at correcting a deficiency of individual nutrients. The reasons for the shot in the foot are several. 1) Deficiencies are very often misidentified; or, 2) there might not actually be a physical deficiency of the nutrient the grower thinks (s)he identified as there could be another antagonistic nutrient, available in excess, in play, example: too much Ca limits Mg uptake - too much P limits uptake of K, Ca, Fe, Cu, Z, ....... ; or, 3) a nutrient could be acting as a synergist, example: an excess of K can cause an increase in the uptake of Mn and Fe, causing a toxicity of all three nutrients which would be read as a deficiency of who knows what; or 4) the deficiency could be culturally caused, example: in saturated soils, low oxygen levels cause Fe (iron) and Mn (manganese) to become electron acceptors. This leads to the precipitation of both, even though these elements might be present in soils at normally adequate levels, and the plant’s inability to assimilate them. Soggy soils also make uptake of Ca difficult or impossible. Al