Does enhanced nutrient availability increase volatile emissions in cranberry?

Nutrient availability impacts plant indirect defenses, such as emissions of herbivore-induced plant volatiles (HIPVs) that attract natural enemies of herbivores. However, the effects are variable depending on the cropping system, and emissions may increase, decrease, or be not affected by nutrient availability. Here, we evaluated the effects of different fertilizer regimes, which varied nitrogen (N), phosphorus (P), and potassium (K) availability, on HIPV emissions in cranberry, Vaccinium macrocarpon Ait. Plants included six cranberry varieties that were subjected to four different fertilizer regimes and either noninduced or induced with methyl jasmonate (MeJA), an elicitor of HIPVs, in a 6 × 4 × 2 factorial design. Results show that enhanced NPK fertilizer applications increased total HIPV emissions in MeJA-treated cranberries, regardless of variety. This effect was due to an increase in plant fresh weight. Although the ecological effects of increased HIPV emissions need to be investigated, these findings may have implications for natural enemy manipulation in agro-ecosystems.