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Laboratory Method to Evaluate Wheat Seedling Emergence from Deep Planting Depths
Author(s) -
Schillinger William F.,
Schofstoll Steven E.,
Smith Timothy A.,
Jacobsen John A.
Publication year - 2017
Publication title -
agronomy journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 131
eISSN - 1435-0645
pISSN - 0002-1962
DOI - 10.2134/agronj2016.12.0715
Subject(s) - sowing , agronomy , seedling , soil water , environmental science , water content , precipitation , cultivar , moisture , habit , yield (engineering) , biology , geography , soil science , geology , psychology , materials science , geotechnical engineering , meteorology , metallurgy , psychotherapist
Core Ideas Stand establishment is the biggest factor afffecting winter wheat yield in the low‐precipitation region. Winter wheat seed is planted as deep as 20 cm below the soil surface to reach adequate soil moisture. Determination of a cultivar's emergence ability in the field is limited to a short time window once a year. We developed a laboratory method to to accurately measure emergence in pots from deep planting depths. Laboratory and field results were strongly correlated under a wide range of soil water potentials.Planting depth effect on seedling emergence is an important concern for many crops grown around the world. Farmers in the low‐precipitation (<300 mm annual) winter wheat ( Triticum aestivum L.) (WW) production region of the Inland Pacific Northwest of the United States (PNW) plant seed as deep as 20 cm below the surface of summer‐fallowed soils with deep‐furrow drills to reach adequate seed‐zone moisture. Seedlings need to emerge through 12 to 15 cm of soil cover, most often under marginal seed‐zone water potentials. Successful stand establishment is the most critical factor affecting WW grain yield potential in the region. We developed a laboratory method to accurately assess WW emergence from deep planting depths in pots. To test the methodology, we first conducted a 4‐yr field experiment to measure emergence of four WW cultivars having either standard‐height or semi‐dwarf growth habit. Depth of soil cover over the seed was 14 cm and seed‐zone water potential over the 4 yr ranged from very dry (–0.69 MPa) to wet (–0.40 MPa). Next, a factorial laboratory pot experiment was conducted using the same WW cultivars and soil seed‐zone water potentials similar to those during the 4 yr in the field. Statistical comparison between field and laboratory emergence data showed a strong correlation ( r = 0.71, p < 0.01) for median time to emerge. We describe the step‐by‐step procedure for conducting a laboratory pot experiment to measure WW emergence from deep planting depths under a wide range of water potentials.