|Karlen, Douglas - Doug|
Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/28/2005
Publication Date: 3/27/2006
Citation: Schwarte, A.J., Gibson, L.R., Karlen, D.L., Liebman, M., Jannink, J. 2006. Planting date effects on winter triticale grain yield and yield commponents. Crop Science. 46:1218-1224. Interpretive Summary: Incorporating a third crop into traditional corn and soybean farming systems in the northern Corn and Soybean Belt could help producers distribute their labor and equipment demands through more of each calendar year, provide an alternate higher amino acid feed source for swine, and improve environmental quality by increasing the portion of each calander year that fields are partially covered by living crops. This study was conducted to help determine the optimum planting date for winter triticale throughout Iowa. Delaying the planting date from mid-September to mid-October reduced grain yield more in northeast Iowa than either central or southwest Iowa. Although the number of seeds per head increased as planting was delayed, the number of spikes (plants producing heads) decreased. There was no measurable effect of planting date on the weight of individual seeds. This research provides important guidelines for producers interested in growing triticale in Iowa and demonstrates the potential for an alternate crop that would also provide positive environmental benefits by taking up residual soil nitrogen and reducing soil erosion following a soybean crop.
Technical Abstract: Winter triticale (XTriticosecale Wittmack) has the potential to introduce valuable economic and environmental benefits to U.S. grain production systems. In order to maximize triticale value, research was conducted to identify planting dates that allow maximum productivity after soybean [Glycine max (L.) Merr.]. Winter triticale was planted at 10-day intervals from 15 September to 15 October at three Iowa locations: central, northeast, and southwest over three growing seasons: 2001-02, 2002-03, and 2003-04. Grain yields tended to be greatest at southwest locations. Delaying planting from late-September to mid-October reduced grain yields by 11.3, 14.2, and 25.2% at central, northeast, and southwest locations, respectively. Spikes per square meter decreased from 469 to 393 and seeds/spikes increased from 35.9 to 39.4 as planting was delayed from mid-September to mid-October. Increased seeds per spike could not fully compensate for decreased spikes per square meter with delayed planting, making spikes per square meter the most influential component of grain yield as planting was delayed. Planting date did not affect seed weight. Yield was greatest when at least 300 growing degree days (GDD) (base 4 degrees C) accumulated between planting and 31 December. Winter triticale would most likely be placed after soybean in Iowa, suggesting that a two- to three-week period would be available for planting winter triticale without diminished yield caused by late planting.