Seed dormancy, germination, emergence and seed longevity in Galinsoga parviflora and G. quadriradiata. (31st October 2013)

• Record Type: Journal Article
• Authors: De, B; Devos, R; Claerhout, S; Bulcke, R; Reheul, D; Andersson, Lars
• Is Part Of: Weed research. Volume 54:Number 1(2014:Feb.)
• Page Start: 38
• Page End: 47
• Publication Date: 2013-10-31
• Subjects: Weeds -- Control -- Periodicals; Herbicides -- Periodicals; 632.5
• DOI: 10.1111/wre.12055
• Languages: English
• ISSNs: 0043-1737

Abstract

<abstract abstract-type="main" id="wre12055-abs-0001"> <title>Summary</title> <p> <italic>Galinsoga quadriradiata</italic> (hairy galinsoga) and <italic>Galinsoga parviflora</italic> (smallflower galinsoga, gallant soldier) are very troublesome weeds in many vegetable row crops in Europe. To optimise management strategies for <italic>Galinsoga</italic> spp. control, an in‐depth study of germination biology was performed. Germination experiments were conducted to evaluate the impact of light and alternating temperatures on germination of a large set of <italic>Galinsoga</italic> populations. Seedling emergence was investigated by burying seeds at different depths in a sandy and sandy loam soil. Dormancy of fresh seeds harvested in autumn was evaluated by studying germination response in light at 25/20°C with and without nitrate addition. Seed longevity was investigated in an accelerated ageing experiment by exposing seeds to 45°C and 100% relative humidity. <italic>Galinsoga</italic> spp. seeds required light for germination; light dependency varied among populations. Seedling emergence decreased drastically with increasing burial depth. Maximum depth of emergence varied between 4 and 10 mm depending on soil type and population. In a sandy soil, emergence percentages were higher and seedlings were able to emerge from greater depths than in a sandy loam soil. Freshly produced <italic>G. parviflora</italic> seeds, harvested in autumn, showed a varying but high degree of primary dormancy and were less persistent than <italic>G. quadriradiata</italic> seeds that lack primary dormancy. Lack of primary dormancy of freshly harvested <italic>G. quadriradiata</italic> seeds and light dependency for germination may be used to optimise and develop <italic>Galinsoga</italic> management strategies.</p> </abstract>