Plant production in indoor farming systems offers significant advantages compared to open field orgreenhouse production systems. Especially in terms of quality and the ability for automation the system is superior to the conventional production systems. Concerning resource consumption indoor farming has considerable advantages in regard to water consumption and the use of pesticides.The main disadvantage is the high consumption of electrical energy. Taking advantage of the specific benefits or eliminating the disadvantages, for example by using renewable energies, different potentials and fields of application for indoorfarming arise.The paper outlines the potentials and future fields of application of indoor farming considering the specific differences to conventional production systems related to resource consumption, quality and automation.

The development of primordial roots of Euphorbia pulcherrima cuttings coincides with a significant increase in photosynthesis. Therefore, Svenson and Davies (1990) suggested that supplementary lighting has no effect on root development of Euphorbia pulcherrima cuttings before primordial roots develop. In this study this hypothesis was experimentally challenged. Cuttings were cultivated with supplementary lighting from the day of sticking and compared to cuttings that were exposed to the same lighting after primordial root development. Our data show that both sets of cuttings developed equally well and both did better than cuttings that were cultivated without supplementary light. Moreover, the data show that light quality had a major impact on root number, length and weight. Therefore, this study confirms the hypothesis of Svenson and Davies (1990) and shows that the positive effect of supplementary lighting is partially mediated by photoreceptors.

The intensity, and consequently the energy consumption, of light emitting diodes (LEDs) can be regulated. Therefore, LEDs can be implemented in new, dynamic energy saving strategies. Recently it has been shown that a program, which adjusts the intensity of a LED to the current solar PAR, reduced its energy consumption by 20%. The effect of a dynamic LED lighting on ornamental crops has not been tested. In this study we compared the growth of the model plant Helianthus annuus under a dynamic versus a static, control LED lighting. The data of this study show that the dynamic LED consumed 21% less energy than a control LED. However, there was no difference in crop quality or time to anthesis.

Rosmarinic acid (RA) and caffeic acid (CA) are potent antixodiants and show antimicrobial activity against many fungal plant pathogens. Their biosynthesis employs enzymes of the phenylpropanoid pathway, a pathway that in mustard is regulated by phytochrome. If RA biosynthesis is regulated by phytochromes one would expect that the RA level correlated with the ratio of red to far-red light. In this paper we tested this hypothesis by growing basil and borage under different ratios of red to far-red light. CA and RA contents were measured with state of the art LC-MS/MS. Regression analysis showed that there is a significant inverse correlation of the ratio of red to far-red light and the content of RA, but not of CA. Hence, we conclude that RA biosynthesis is regulated by phytochrome.

Light quality affects plant morphology. Hence, light quality is an important factor in the cultivation of ornamental plants. The recent advances in LED technology allow producers to adjust light quality to manipulate plant growth. For growers of ornamental plants the primary aim regarding plant morphology is to keep plants short and compact with attractive flowers. However, data on the effect of light quality on plant morphology are still sparse. This study provides data on the effect of different LED light regimes on height and fresh weight of shoot and flower, leaf area and compactness of the model plant Helianthus annuus. Regression analysis of these data shows that red light promotes compact growth.