Vegetative regeneration of Calluna vulgaris at different ages and fertilizer levels

Vegetative regeneration of Calluna vulgaris after cutting was studied in relation to the ages of plants and levels of fertilization. Vegetative regeneration from the stem base decreased steadily in stands that were more than 6 years old. From this age on the number of newly formed sprouts also decreased significantly. The growth rate of the young sprouts increased with plant age and was highest in plants of 13 years and older. Contrary to earlier reports, no sudden decline of vegetative regeneration appeared in plants older than 15 years, but the total regenerative yield per surface area of stands of that age was very low. Fertilization depressed the vegetative regeneration capacity of Calluna, and regenerative capacity from the stem base was positively related to the amount of carbohydrate reserves in the stem. Reserves in stems of young plants were significantly larger than in old ones and reserves in stems of fertilized plants were significantly smaller than in unfertilized ones.