Effect of emergence time, inter- and intra-specific competition on growth and fecundity of Echinochloa crus-galli in dry-seeded rice

Awan, Tahir Hussain and Chauhan, Bhagirath Singh (2016) Effect of emergence time, inter- and intra-specific competition on growth and fecundity of Echinochloa crus-galli in dry-seeded rice. Crop Protection, 87 98-107. doi:10.1016/j.cropro.2016.05.004


Author Awan, Tahir Hussain
Chauhan, Bhagirath Singh
Title Effect of emergence time, inter- and intra-specific competition on growth and fecundity of Echinochloa crus-galli in dry-seeded rice
Formatted title
Effect of emergence time, inter- and intra-specific competition on growth and fecundity of Echinochloa crus-galli in dry-seeded rice
Journal name Crop Protection   Check publisher's open access policy
ISSN 0261-2194
1873-6904
Publication date 2016-09-01
Year available 2016
Sub-type Article (original research)
DOI 10.1016/j.cropro.2016.05.004
Open Access Status Not Open Access
Volume 87
Start page 98
End page 107
Total pages 10
Place of publication Amsterdam, Netherlands
Publisher Elsevier BV
Collection year 2017
Language eng
Formatted abstract
Since 2005, the evolution and spread of herbicide-resistant Echinochloa crus-galli biotypes have posed a serious threat to crop production in the Philippines. A comprehensive knowledge of E. crus-galli ecology and fecundity is fundamental in managing different biotypes of this weed. It was hypothesized that (a) high weed plant density produces more biomass and fertile seeds per unit area, (b) rice interference reduces the biomass and fecundity of the weed, and (c) a delay in weed emergence reduces the soil seed bank. In 2013, experiments were conducted in the wet season (WS) and dry season (DS), to understand the effect of E. crus-galli densities (40 and 80 plants m-2) on its growth, survival, and fecundity, with varying emergence times of 2, 15, 30, and 45 d after rice emergence (DARE). Relative to the weed plants grown without rice interference, E. crus-galli growth and seed production was lower in the presence of rice. Percent survival and plant height of E. crus-galli declined in a linear manner in the DS, and declined in a quadratic manner in the WS. Tiller number, inflorescence number, inflorescence biomass, and shoot biomass per plant declined in an exponential manner, with a delay in emergence of each cohort relative to rice. Across rice seeding rate, weed density, and emergence time, there was a linear relationship (y = 110x - 272 in the DS and y = 100x - 220 in the WS) between E. crus-galli shoot biomass and the number of seeds plant-1. Relative to the late-emerging weed cohorts, E. crus-galli seed production (1320-1579 seeds plant-1), 1000-seed weight (2.2-2.9 g), and seed yield (2808-2334 kg ha-1) were higher when seedlings emerged with the crop (2 DARE). None of the seedlings that emerged 45 DARE produced viable seeds. Seed germination of the first two cohorts (2 and 15 DARE) ranged from 84 to 91%. The delay in emergence of E. crus-galli beyond 30 DARE reduced the percentage of germinable and viable seeds, and increased the percentage of non-viable seeds produced plant-1. The results suggest that cultural weed management approaches that delay the emergence of E. crus-galli can reduce weed biomass and seed production, and is thus valuable for preventing seed rain to the seed bank by noxious weed biotypes in the field.
Keyword Biomass
Emergence time
Seed production
Soil seed bank
Weed seed yield
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: HERDC Pre-Audit
Queensland Alliance for Agriculture and Food Innovation
 
Versions
Version Filter Type
Citation counts: TR Web of Science Citation Count  Cited 0 times in Thomson Reuters Web of Science Article
Scopus Citation Count Cited 0 times in Scopus Article
Google Scholar Search Google Scholar
Created: Sun, 24 Jul 2016, 00:32:02 EST by System User on behalf of Learning and Research Services (UQ Library)