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The effect of thermal time and soil water on emergence of Ranunculus repens
Author(s) -
Rachel Harris,
Doohan,
Gordon,
Jensen
Publication year - 1998
Publication title -
weed research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.693
H-Index - 74
eISSN - 1365-3180
pISSN - 0043-1737
DOI - 10.1046/j.1365-3180.1998.00117.x
Subject(s) - repens , biology , seedling , botany , air temperature , environmental factor , arable land , horticulture , zoology , ecology , geography , meteorology , agriculture
The effect of temperature and soil available water (AW) on the emergence of Ranunculus repens ␣L. was examined in artificial media in growth chambers. Two seed populations, `arable type' and `wild type', were investigated. Moisture levels were 20%, 40%, 60% and 80% AW, and temperatures were 10/5 °C, 15/7 °C, 20/10 °C and 25/15 °C. Time to onset of emergence varied from 11 to 28 days for both seed populations, primarily as a result of mean temperature. Mean thermal time (TT) required for the onset of emergence of both populations was 251 ± 45 TT. Total emergence of the `arable type' R. repens varied from 3% at 10/5 °C and 20% AW to 30% at 25/15 °C and 60% AW. Total emergence of the `wild type' was greater, ranging from 4% at 10/5 °C and 20% AW to 57% at 25/15 °C and 80% AW. Temperature and AW significantly affected total emergence. A logistic response was displayed for the cumulative emergence of both populations. Seedling emergence models based on TT were developed for both populations at each of the four levels of AW.