I'm putting together a plan for a fruit wine business, and need to calculate expected yields for fruit trees each year from the date of planting. I have found various resources that provide 'time to first fruiting' and 'yield at maturity', but rarely can I find information stating the yield at first fruiting or time to maturity. Without these pieces of information, it is impossible to estimate expected yield from year to year.
For my business plan, I need to calculate the yield of various plants from the year of planting until year 5. These will be for specific cultivars, and to give some context, I am interested in Blackberry, Damson, Elderberry (and Elderflower), Nettle and Rhubarb.
I am aware of how hopelessly imprecise any such calculations would be; locality and climate clearly have a huge impact. Nevertheless, this is a bureaucratic exercise I need to go through; I have to provide estimated figures for a business plan. Given the information available from most sources (time to fruiting and yield at maturity), how do I go about calculating an expected yield for years 1 to 5?