Lonicera maackii is an invasive shrub in North America for which allelopathic effects toward other plants or herbivores have been suspected. We characterized the major phenolic metabolites present in methanol extracts of L. maackii leaves. In addition, we examined the effects of methanol-water extracts of L. maackii leaves on seed germination of a target plant species and on feeding preference and growth rate of a generalist insect herbivore. A total of 13 individual major and minor compounds were detected in crude leaf extracts by high-performance liquid chromatography coupled to electronspray ionization-tandem mass spectrometry (ESI-MS/MS). Extracts were dominated by two major flavones, apigenin and luteolin, and their glucoside derivatives, apigenin-7-glucoside and luteolin-7-glucoside. Quantities of these compounds, along with chlorogenic acid, varied between two sampling points. Leaf extracts that contained these compounds were inhibitory to seed germination of Arabidopsis thaliana. In addition, treatment of artificial diet with leaf extracts deterred feeding of the generalist herbivore, Spodoptera exigua, in choice experiments but had no effect on growth rate in short-term no-choice bioassays. Purified apigenin tended to deter feeding by S. exigua and inhibited seed germination of A. thaliana. We conclude that leaves of L. maackii contain phenolic compounds, including apigenin and chlorogenic acid, capable of having biological effects on other plants and insects.

In addition to resource competition, allelopathy is believed to contribute to the invasiveness and impact of several plant invaders of North America. In this study, we examined whether aqueous leaf extracts of Alliaria petiolata and Lonicera maackii, two invaders of deciduous forests in North America, affected growth and reproduction of a target nonmycorrhizal plant and whether effects varied across a soil fertility gradient. While nutrient addition substantially improved the performance of Arabidopsis thaliana grown in field soils in pots in a growth room, addition of A. petiolata extracts to these soils had no significant independent or interactive effects on growth or reproduction. In contrast, addition of L. maackii extracts both directly reduced growth and reproduction of A. thaliana and greatly constrained increases in growth and reproduction of A. thaliana in response to increasing nutrient availability. Use of a nonmycorrhizal target plant revealed that effects of L. maackii were independent of allelopathic effects on mycorrhizae, an effect attributed to A. petiolata in other studies.

A weak electrical field has a stimulatory effect on germination of seeds and the early growth of young plants. Waldo bean seeds were placed in a chamber with moistened filter paper. Oppositely charged aluminum plates were used to stimulate growth. The top plate was,suspended above the filter paper to eliminate the possibility of a direct current flow through the paper. Each set of samples was examined after 5 days. The average root length of the test groups was significantly greater than that of the control groups. Additional experiments suggested that the rate of growth of the plants in soil was enhanced by applying a weak electric field to the soil. Using electricity to stimulate better germination has many practical applications. A current agricultural practice is to germinate seeds in dissolving tubes for planting as individual plants. Results of these experiments suggest that applying an electric current to the germinating seeds would stimulate them to grow more vigorously for more successful growth in the field, The use of electricity may have important applications as art adjunct to organic farming practices. Experiments are under way to apply the use of electricity to hydroponic systems. Foster, K.R. and H.P. Schwann. 1986. In: C. Polk and E. Postrow (eds.). CRC handbook of biological effects of electromagnetic fields. CRC Press, Inc., Boca Raton, Fla. Weaver, J.C. and R.D. Astumian. 1990. The response of living cells to very weak electric fields: The thermal noise limit. Science 247:459-462.

The millennium and fears of its ‘bug’ confirmed how far the modern world remained in thrall to exacting temporalities. Some early C21st-century novels – e.g. by W.G. Sebald– extended the resistive strategies of modernism, alongside recent ones described in Chapter Six. Others – by Don DeLillo and Thomas Pynchon – suggested different strategies for evading temporal constraints, and also some of the latter’s origins in the eighteenth century ‘Age of Reason’ and Industrial Revolution. Examining this age clarifies how far the rise of the novel (in its modern mode) may be attributed to newly-exacting influences of the clock on contemporary life, and how extensively these were resisted by early practitioners of the form, particularly Laurence Sterne. Resistance to the clock’s orderings can of course be further retraced, though Shakespeare’s plays – even back to Roman times – with much C20th writing suggesting it shares in wider, perennial antinomies between human reason, or agency, and nature. Though perhaps perennial, such antinomies should be seen as historically specific in scale and nature, and particularly inflected within C20th imagination. Tracing this inflection, as this study has shown, offers a powerful means of understanding the century’s history and the ways this has shaped its imagination and narrative forms.