Heavy nitrogen applications to bedding plants will primarily cause which of the following?

Heavy nitrogen applications to bedding plants primarily promote vegetative growth due to nitrogen's critical role in plant development. Nitrogen is an essential macronutrient, fundamental for synthesizing amino acids, proteins, and nucleic acids. It encourages foliage development and increases plant vigor, leading to lush green leaves and upward growth.

In bedding plants, an excess of nitrogen can result in rapid vegetative growth at the expense of other growth aspects. This often means that the plant may focus its energy on growing leaves and stems rather than producing flowers or fruits, which can delay flowering or negatively impact the plant's reproductive phase. As a result, plants treated with high levels of nitrogen often exhibit robust foliage but may not initiate floral development as effectively.

The other options relate to different physiological processes or outcomes not primarily driven by heavy nitrogen application. For instance, floral initiation typically relies more on factors such as light, temperature, and other nutrients, while lower soluble salts in the soil would indicate a different nutrient management strategy, and longer stem internodes can sometimes result from other growth factors, such as light intensity or plant spacing rather than solely nitrogen levels.