Inhibiting effect of shallow seed burial on grass weed emergence

Abstract

Loddo D., Vasileiadis V.P., Masin R., Zuin M.C., Zanin G. (2016): Inhibiting effect of shallow seed burial on grass weed emergence. Plant Protect. Sci., 52: 64-69.The efficacy of superficial tillage as a sustainable tool to reduce the emergence of Digitaria sanguinalis, setaria viridis, and sorghum halepense was evaluated with field experiments. Seeds were buried at 1, 2, 5, and 10 cm of depth to simulate seed vertical distribution caused by autumn superficial tillage. Seedling emergence was monitored weekly for two years after sowing. The highest emergence was obtained in the first year after sowing and from 1 and 2 cm. sorghum halepense was only slightly affected by seed burial, with 15% of emergence from 10 cm of depth, while D. sanguinalis was strongly affected, with 4% of emergence from 5 cm. The efficacy of superficial tillage as control tool could vary according to local weed flora.

Eco-biology, impact, and management of Sorghum halepense (L.) Pers.

“…At heavily infested sites, tilling the field six times at 2-week intervals reduced S. halepense rhizome production by 90% (McWhorter 1973). During summer, superficial tillage affected the emergence of S. halepense, with 15% seedling emergence from a 10-cm burial depth (Loddo et al 2016). Furthermore, collection of rhizome fragments after mechanical tillage helped reduce S. halepense reinfestation in an organic red pepper (Capsicum annuum L.) cultivation system of Turkey (Arpaci et al 2016).…”

Germination of Chloris barbata, Cynodon dactylon, and Cyperus rotundus from Angola at Constant and Alternate Temperatures

“…Previous studies have described relevant inhibition of seedling emergence from seeds below 5 cm of depth, even for weed species with larger seed size, such as Alopecurus myosuroides Huds., Digitaria sanguinalis (L.) Scop., Echinochloa crus-galli (L.) Beauv., or Setaria viridis (L.) Beauv. [23,49]. Moreover, daily thermal fluctuations are limited at 5 cm of depth in comparison to the soil surface, and these conditions could inhibit species like C. rotundus, which require alternate temperatures to germinate [30].…”

“…Weed-crop competition and, consequently, the potential yield loss caused by weeds are strongly affected by the timing and magnitude of weed germination and emergence [20], and several management tactics were studied and adopted to promote or hinder weed germination. Surface soil disturbance can promote weed germination and emergence [21,22], while seed burial due to tillage can notably reduce germination [23]. Cover crop or cash crop residues can inhibit weed germination due to allelopathic effects, if incorporated in the soil, or by reducing soil temperature fluctuation and light penetration, if left on the soil surface as dead mulch [24,25].…”