Plant Growth and Soybean Cyst Nematode Response to Purple Deadnettle (Lamium purpureum), Annual Ryegrass, and Soybean Combinations

Abstract

A greenhouse study was conducted to determine the influence of soybean cyst nematode (SCN) –susceptible and –resistant plant combinations on SCN population densities and plant growth. Purple deadnettle, annual ryegrass, SCN-resistant and -susceptible soybean were planted in pots alone or in combination at one plant pot−1. Annual ryegrass and purple deadnettle reduced soybean growth. Pots with SCN-resistant plants had lower numbers of SCN cysts and eggs than pots with SCN-susceptible plants. However, an SCN-susceptible species grown with any of the SCN-resistant plants resulted in higher cyst counts than pots with only SCN-resistant plants. From an SCN management standpoint, this research suggests that there may be no incentive to using annual ryegrass as a cover crop over planting other SCN-resistant crops to reduce SCN population density.

A chemical ecological investigation of the allelopathic potential of <i>Lamium amplexicaule</i> and <i>Lamium purpureum</i>

“…amplexicaule has been shown to reduce the yield of wheat (Triticum aestivum) [4], and has demonstrated allelopathic activity against lettuce (Lactuca sativa) [14]. Similarly, L. purpureum has been shown to reduce the growth of soybeans (Glycine max) [5], and this plant has also demonstrated allelopathic effects on lettuce [16]. Some plant species have demonstrated allelopathic effects toward L. amplexicaule and L. purpureum.…”

“…Both L. amplexicaule and L. purpureum can aggressively spread through fields, pastures, and gardens. L. amplexicaule has been shown to reduce the yield of wheat (Triticum aestivum) [4], and L. purpureum has been shown to reduce the growth of soybeans (Glycine max) [5]. In this work, we test the hypothesis that volatile phytochemical components from these members of the mint family (Lamiaceae) are responsible for the reported allelopathic effects; we have determined the chemical compositions and biological activities of the essential oils from the aerial parts of L. amplexicaule and L. purpureum growing in fields in and near Huntsville, Alabama.…”

Nutritional Requirements of Soybean Cyst Nematodes

“…A summary of the plants invaded by SCN are shown in Table 1. Most hosts of SCN are legumes and are limited to three subfamilies of the Leguminosae; however, approximately 50 genera in 22 families including nonlegumes are also hosts [31][32]. Some plants allow SCN to penetrate plant roots but limit reproduction of SCN [33].…”