Threelobe Morningglory (Ipomoea triloba) Germination and Response to Herbicides

Abstract

Experiments were conducted in the laboratory and screenhouse to determine the effects of scarification; alternating day/night temperatures; light, salt, and water stress; seed burial depth; and rice residue on seed germination and seedling emergence of threelobe morningglory, and to evaluate the response of this weed to commonly available POST herbicides in the Philippines. Germination was stimulated by seed scarification, suggesting that inhibition of germination in this species is mainly due to the hard seed coat. Germination of the scarified seeds was not influenced by the tested temperatures (alternating day/night temperatures of 25/15, 30/20, and 35/25 C) and light. The concentrations of sodium chloride, ranging from 0 to 250 mM, did not influence germination of the scarified seeds of threelobe morningglory. The osmotic potential required for 50% inhibition of maximum germination was −0.35 MPa, although some seeds germinated at −0.6 MPa. Seedling emergence was greatest for the seeds placed on the soil surface (96%), and emergence declined with increased burial depth in soil. The burial depth required for 50% inhibition of maximum emergence was 2.8 cm. No seedlings emerged from a burial depth of 6 cm or greater. Residues of up to 6 Mg ha−1on the soil surface did not influence seedling emergence of threelobe morningglory. The herbicide 2,4-D at 400 g ai ha−1provided excellent control of threelobe morningglory when applied at the four-leaf (100%) and six-leaf (97%) stages. However, at the eight-leaf stage, percent control was reduced to 67% and herbicide rate had to be increased twofold to achieve 95% control. The information gained from this study could contribute to developing components of integrated weed management strategies for threelobe morningglory. Soil inversion by tillage to bury weed seeds below their maximum depth of emergence and early application of an effective POST herbicide could serve as important tools for managing threelobe morningglory.

Seed germination ecology of creeping mannagrass (Glyceria acutiflora) and response to POST herbicides

“…The results of this study imply that light is not a prerequisite for the germination of creeping mannagrass. Similar results have been reported for other weed species, such as three lobe morningglory (Ipomoea triloba L.), prickly sida (Sida spinosa L.), and catchweed bedstraw (Galium aparine L.) (Smith et al 1992;Chauhan & Abugho 2012;Wang et al 2016). Furthermore, seed germination of creeping mannagrass under the dark conditions seems slightly stimulated compared with these in light/dark, this nonphotoblastic characteristic implies that seeds of this weed could germinate under crop canopy coverage conditions and even buried at shallow depth in the soil.…”

“…Similar results have been reported for other weed species, such as three lobe morningglory ( Ipomoea triloba L.), prickly sida ( Sida spinosa L.), and catchweed bedstraw ( Galium aparine L.) (Smith et al . ; Chauhan & Abugho ; Wang et al . ).…”

The role of community composition in grassland response to two methods of exotic forb removal

“…Because 2,4‐D targets dicotyledons, this control method could be used any time that invasive forbs are actively growing, instead of being restricted to periods when invasive forbs are growing and the dominant grasses are dormant (Sheley & Denny, ; Ruffner & Barnes, ). Although 2,4‐D degrades rapidly in soil (Boivin et al ., ), applying selective herbicide to larger areas would require managers to carefully consider the effects on native biodiversity (Sheley & Denny, ), including reductions in seedling survival (Chauhan & Abugho, ). To offset any damage caused by the herbicide, native seeds could be added to prevent reinvasion (Biggerstaff & Beck, ).…”

Tolerance to Glyphosate in Broadleaf Buttonweed and White-Eye Biotypes

“…Secondly, the development conditions of the plants before and after the application of the herbicide, such as solar radiation, temperature, water availability, and relative humidity. Thirdly, the physiological stage of weeds at the time of application, as younger plants present lower defense to the action of the herbicides (Chauhan and Abugho, 2012). Dias et al (2013) verified that day flower plants become four times more tolerant to glyphosate every ten phenological development units on the Biologische Bundesanstalt, Bundessortenamt and Chemical industry (BBCH) scale, adapted from Hess et al, 1997.…”