So - help me understand the differences in ethylene physiology in different apples - I am familiar with textbook graphs and the climateric respiration pattern that is a generalized explanation for maturity/senescence in apples, but there are apples that don't seem to fit that pattern, specifically GoldRush and HoneyCrisp, where ethylene production/concentrations do not seem to spike, but seem to 'peak' at a low level of 1-5ppm rather than spiking to 10's to 100's of parts per million -
GoldRush and HoneyCrisp are also associated with maintaining firm, crisp flesh quality over a long storage life (at least the fraction of HC that don't bitter pit or soft rot or decline from any of the several other maladies to which it is subject) - is the low ethylene synthesis the explanation for this? If HoneyCrisp is exposed to high concentrations of ethylene does it then soften and age like a 'normal' apple? Or is there something else going on? MCP binds to ethylene receptor sites and so prevents ethylene from having its normal effect on respiration and maturation - does the treated fruit still exhibit the climateric peak in ethylene generation? But the ethylene is unable then to have its effect because of the blocked sites? From what I have gathered, MCP is applied at some point after significant ethylene production has initiated, but likely before production has peaked. Thanks for any input, feel free to correct any misconceptions on my part, I won't take anything personally - David Doud grower, Indiana -15F last week _______________________________________________ apple-crop mailing list apple-crop@virtualorchard.net http://virtualorchard.net/mailman/listinfo/apple-crop
