Hi Chris, leaf curling and browning is a normal aspect of plant aging and can be easily noticed in the oldest leaves of plants that are grown on the ground or not pruned regularly. This aspect of plant senescence can be easily taken for disease symptoms . Occasional pruning of these leaves, especially if the plants are grown on poles, is only beneficial as dead tissue ( the brown curled leaves) generally attracts all sorts of hungry beasts. Withered leaves , brown leaves and flowers, small discolored fruits with very little jelly and small seeds are a sign the plant has been stressed and slowed down very much its reproductive growth. Could you please post some pics of fruits cut in half ? If the plants are grown on the soil, very close together, and its hot outside, my guess is they will experience even a higher stress as there is heat coming from the soil as well and no ventilation in between the plants/leaves.
To try and save your plants I would also suggest shading, removal of dead tissue and adequate watering. Usually heat stress is most deleterious when the plant is young and flowering - so you should look back at the temperature charts 3 weeks ago; the fact that you have fruits already means the plants are mature and may not produce new flower buds- although MM is of the indeterminate growth type. However, without shading I dont think the fruits already present will keep growing, and even if they do they will not be properly developed , no juice, and little taste compared to their full potential.
If you live in a hot climate area I suggest a small trial next year with 5-6 different tomato cultivars previously known to be heat tolerant ( and also have tastier sweeter more flavorful fruits) in the field and also of determinate growth -especially if you grow them for your own use. Money Maker is a commercial cultivar mostly used for greenhouse culture but of course one can also grow them in field( backyard conditions that is) providing enough shading. Here some useful varieties, especially if it doesnt rain a lot in your area : http://www.tomatodirt.com/tomatoes-fo...
I would suggest hairloom tomatoes that also retain a certain tolerance to diseases instead of super producing hybrids that would need spraying etc. In my opinion the best site to order seeds from is this passionate grower in Germany, he has thousands of cultivars not only of tomato but also several other vegetables. Only trouble is one needs to know a bit of german..or dutch: http://tomaten.bplaced.net/tomatenhah...
hi Chris ! how is the project going ? Still waiting for the fruit pics :). about 7 years ago.