Influence of environmental factors, cultural practices, and herbicide application on seed germination and emergence ecology of Ischaemum rugosum salisb

Lim, Charlemagne Alexander A., Awan, Tahir Hussain, Cruz, Pompe C. Sta. and Chauhan, Bhagirath Singh (2015) Influence of environmental factors, cultural practices, and herbicide application on seed germination and emergence ecology of Ischaemum rugosum salisb. PLoS One, 10 9: 1-28. doi:10.1371/journal.pone.0137256


Author Lim, Charlemagne Alexander A.
Awan, Tahir Hussain
Cruz, Pompe C. Sta.
Chauhan, Bhagirath Singh
Title Influence of environmental factors, cultural practices, and herbicide application on seed germination and emergence ecology of Ischaemum rugosum salisb
Formatted title
Influence of environmental factors, cultural practices, and herbicide application on seed germination and emergence ecology of Ischaemum rugosum salisb
Journal name PLoS One   Check publisher's open access policy
ISSN 1932-6203
Publication date 2015-09-01
Sub-type Article (original research)
DOI 10.1371/journal.pone.0137256
Open Access Status DOI
Volume 10
Issue 9
Start page 1
End page 28
Total pages 28
Place of publication San Francisco, CA, United States
Publisher Public Library of Science
Language eng
Formatted abstract
Ischaemum rugosum Salisb. (Saramolla grass) is a noxious weed of rice that is difficult to control by chemical or mechanical means once established. A study was conducted to determine the effect of light, temperature, salt, drought, flooding, rice residue mulch, burial depth, and pre-emergence herbicides on seed germination and emergence of I. rugosum. Germination was stimulated by light and inhibited under complete darkness. Optimum temperature for germination was 30/20°C (97.5% germination). Germination reduced from 31 to 3.5% when the osmotic potential of the growing medium decreased from -0.1 to -0.6 MPa and no germination occurred at -0.8 MPa. Germination was 18 and 0.5% at 50 and 100 mM NaCl concentrations, respectively, but was completely inhibited at 150 mM or higher. Residue application at 1–6 t ha-1 reduced weed emergence by 35–88% and shoot biomass by 55–95%. The efficacy of pre-emergence herbicides increased with increasing application rates and decreased with increasing rice residue mulching. The efficacy of herbicides was in the order of oxadiazon> pendimethalin> pretilachlor. At 6 t ha-1, all herbicides, regardless of rates, did not differ from the control treatment. I. rugosum seeds buried at 2 cm or deeper did not emerge; however, they emerged by 4.5 and 0.5% at 0.5 and 1 cm depths, respectively, compared to the 39% germination for soil surface seeding. Flooding at 4 DAS or earlier reduced seedling emergence and shoot biomass while flooding at 8 DAS reduced only seedling emergence. The depth and timing of flooding independently reduced root biomass. Flooding at 4 and 6 cm depths reduced the root biomass. Relative to flooding on the day of sowing, flooding at 8 DAS increased root biomass by 89%. Similarly, flooding on the day of sowing and at 2 DAS reduced the root–shoot biomass ratio. Under the no-flood treatment, increasing rates of pretilachlor from 0.075 to 0.3 kg ai ha-1 reduced weed emergence by 61–79%. At the flooding depth of 2–4 cm, pretilachlor reduced weed emergence and shoot and root biomass, but the differences across rates were non-significant. Information generated in this study will be helpful in developing integrated weed management strategies for managing this weed.
Keyword Southern Australia
Light sensitivity
Weed
Rice
Arabidopsis
Induction
Canopies
Dormancy
System
Growth
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: Queensland Alliance for Agriculture and Food Innovation
Official 2016 Collection
 
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