by Stewart Brandt, Northeast Agriculture Research Foundation
In June 2013, 0.22 lb/ac of foliar EDTA chelated copper was applied at the flag leaf to established timothy (3 locations) and hybrid bromegrass (1 location) on replicated miniplots in the Choiceland, Nipawin, and White Fox, SK regions. This was repeated in June of 2014, and we added 2 other liquid Cu foliar treatments; dropped one unresponsive site and added another potentially responsive hybrid bromegrass site. At harvest we evaluated treatment effects on seed yield in both years and on straw yield in 2014.
At Site 1 in 2013 (a field with a history of copper fertilizer application) seed yield of timothy did not increase when copper was applied, and showed a weak tendency to decline slightly. At two other sites in 2013, copper fertilization increased seed yield of timothy by 20 and 29%. At Site 4, copper fertilizer increased seed yield of hybrid bromegrass by 30%. The three sites where copper did increase yield all had no known history of copper application. The combined analysis of the three sites that had no known history of copper fertilization indicated that the copper response was statistically significant at the 5% probability level.
During 2014, foliar copper had minimal impact on straw yield at 3 of 4 locations, and tended to increase straw yield at one location. Seed yield averaged across the 3 copper treatments and 4 locations were 126% of the untreated check. This ranged from a low of 97% at the least responsive site to 155% of the check at the most responsive site. There was no clear indication that any foliar copper product was superior to another.
These results suggest that low seed yield with forages may reflect copper deficiencies. Forage seed growers in these regions who suspect copper deficiencies should consider applying copper to test strips in their fields to verify both the presence and magnitude of responses. Results also confirm that application of foliar copper at relatively low rates can be effective at correcting deficiencies. Results also confirm that applying foliar copper to mini-plots and comparing yield to adjacent untreated areas is an effective way of identifying where copper applications may be economic.
For additional information about copper fertilization and effectiveness of different forms of copper, see the Research Results page ‘Some Useful Information about Copper (Cu) and Copper Fertilizers’ on the Northeast Agriculture Research Foundation website at www.neag.ca
The Northeast Agriculture Research Foundation would like to express their gratitude to SFSDC, Nexus Ag Business Inc., and YARA Canada Inc. for financial support and for providing copper product. The technical support of Darwin Leach, Karen Strukoff, Kerry O’Brien and Clayton Myhre (DLF-Pickseed) is acknowledged.
Posted June 4, 2015