High temps. Temps above 90 F for periods of 2 days or longer will do this. The plant is just trying to survive. Fruiting take a lot of energy and water so the plant will drop flowers so the plant can live to fruit later when the temps are consistently below 90 F.

Carolyn can it not be tobacco or nicotine related without being TMV? Are you a specialist in the field? ***** Taz, that's a double negative but if you're asking if tobacco products can be the cause of disease with tomatoes without TMV possibly appearing,then the answer is no, I know of no documented disease caused just by smoking products. TMV was originally insected transmitted until TMV tolerant tobacco was grown commercially in the US when now it's different and mechanical transmission is what happens in most cases and especially in commercial greenhouses. I hope one of those two answers is appropriate to your question. Am I a specialist? You can read some of my background at my page. Do I have a Ph.D in plant infectious diseases, no I don't. But I was raised on a farm where we had acres of tomatoes, will be 71 in June, have grown about 2500 hundred varieties myself, have a good understanind of infectious diseases in humans, which I taught, as well as vegetables and fruits, worked with the Cornell Coop Ext in two different counties, have done lots of teaching of Master Gardeners as well as field days re diseases, have been posting online about tomato infectious diseases since 1989 and have done clinics on IDing tomato diseases here and there. And have wrote a book about Heirloom Tomatoes, after being asked to do so. I've been retired since 1999 , from teaching, b'c of mobility problems, severed four quads in 2004, have two new hips and still have to use a walker, and still continue to grow stuff in much less numbers, all my gardening done by someone else. And being retired I have the time to read/post at four online message sites that I chose and as a Moderator at two of them. So it's up to you to decide if I have a good undertanding of tomato diseases and diagnosis of many of them. No one person, even a tomato pathologist, knows it all, but I usually have enough information to help folks looking for answers online to the best of my ability and I don't know ALL the answers either. Carolyn, being also honest but not rude as you posted above.And who also finds this site is sometimes contentious , as do many others, which is why in 2006 many of us moved to a different site but I usually drop in here from time to time anyway as do a few others who also moved elsewhere.

Tatiana site lists it as OP as dehybridization result? %%%%% Lee Goodwin has a fine site and is always breeding new ones in addition to the ones sent to him which you saw with Kazachka, which I sent to him for instance. All of his ones named Ambrosia,different colored ones, were bred with Sungold F1 as one parent, I can't remember which one it was but I offered it in a recent seed offer elsewhere, initial seeds from Lee, If you look at what I cut and pasted to here you'll see that it came from the same line as the Ambroia ones, so I would assume that Sugar Drop still has some Sungold genes in it. Lee posted this elsewhere: (The Ambrosias and the Copper Currant have wild genes which may help a bit with whatever is going around. Good photos, Robin. Do either of your Ambrosia plants have that spicy, skunky aroma? The smaller one is closer to the Sugar Drop which came out of that line. I would hang onto it. Perhaps we can trade some seed. ) The skunky aroma is a direct reference to Sungold F1 foliage although in his link below he says just spicy. Sugar Drop is new for 2013 and I don't remember seeing anyone say they were growing it this past summer, but who knows for sure since I only participate at a few message sites. Carolyn Here is a link that might be useful: Sugar Drop

What is going wrong? "Blossom-Drop" is a condition suffered by tomatoes, peppers, snap beans, and some other fruiting vegetables where the plant blooms but fails to set fruit, the blooms die and fall off. It may be caused by the use of excess nitrogen fertilizers or dry windy conditions, but the most common cause is temperature extremes. Tomatoes, peppers and beans are especially picky about the air temps when it comes time to set fruit. If the night temps fall below 55 or rise above 75 or if the day temps are above 90, the pollen becomes tacky and non-viable. Pollination cannot occur. If the bloom isn't pollinated, the bloom dies and falls off. What can I do? Water the plants deeply once a week, mulch heavily to maintain constant soil moisture levels, establish windbreaks as needed, avoid using excessive amounts of nitrogen fertilizers, and wait for temperatures to moderate and stabilize. Earlier timed planting can help attain fruit set prior to the on-set of high temps, and the use of protection can compensate for cool nights. Some recommend attempting hand-pollination with an artist brush or a gentle shaking of the plant/cage/support prior to the hottest part of the day will also help. Fruit set will resume when temperatures moderate. Hormone sprays, such as "Blossom Set", may prevent some blossom drop due to LOW temperatures. However, the resulting fruit are often misshapen. But studies prove that hormone sprays do not prevent blossom drop due to HIGH temperatures.