So, how many generations?

Another doughty question. Generation time in our black walnuts is somewhere from 8-15 years, depending on the individual. This is not necessarily the same as the age at which a tree produces a its first nut. The generation time requires that we, as service managers, have enough time to identify and quantify key abilities. If a tree first fruits at six years of age, it is likely to be year 8 or 9 before we have enough data to decide whether we want to add its offspring to our biomass plantations. The nuts will not germinate before the subsequent year. Some trees are not producing fruit even at 15 years of age. Thus, while they are providing environmental services, unless we can identify an income stream independent of fruit production, these less prolific trees are unlikely to add to the farm's bottom-line. As we use a planting layout which requires that some trees be removed to leave room for others to grow, it is more likely to be these less-prolific trees which pay the ultimate price. The first identification of mother trees for on-planting was made in 2007. Offspring will germinate next year. From here on while those offspring will not be evaluated for several years, we will continue to on-plant from useful mother trees, according to several criteria.