The split of tomato fruits is an important and complex physiopathology due mainly to water concentration jerks in the soil part which the plant explores. The hybrid grafting Blue Devil produces a very high number of capillary roots that explore the soil searching useful feedings for the plant. The root gear, despite the fact that it is much developed and provided of many principle (fittoni), it is not aggressive in water absorption. How many times have you noticed a luxuriant/blooming vegetation even after having stopped irrigations? The biggest part of grafting it is in fact able to absorb water at the inside of very deep levels of soil over than a humidity portion that is usually not available for a normal root.
This feature can be explained with the term of aggressiveness. The lower aggressiveness of Blue Devil roots allows the grower to manage his cultivation at the same level of a without foot system from an water and feeding point of view. During winter periods in fact, water management with wild grafting is very complicated. (Because) The stand-out aggressiveness of wild grafting do not allow to well manage the cultivation, especially during critical moments like the ones that prevent the harvest of fruit stages when a little jump of humidity of the soil (that can be relied at many environmental factors) has the possibility to bring serious split phenomena with the following loss of the production.
With Blue Devil the grower has the chance to suspend/ decrease water availability to easily proceed on the harvest operation and, after that, restart the irrigation reducing the danger of productivity loss. Tests conducted on split talking sensitive products grafted on Blue Devil made us reveal an (important) decrease of splitted fruits of the 65% in comparison with the wild witness. Last but not least it is important to stress that the possibility to give water to plants in winter corresponds to the possibility to continue to give easily feeding elements that the plant needs during its specific phenologycal (fenologica) phase solving so maturation, quality and vegetative-productive balance issues/problems.
Find here a link to a little publication by University of Florida:
and another to a (agraria) forum (italian) http://www.forumdiagraria.org/orticoltura-f42/spaccatura-pomodoro-t1189.html