|
|
||||||||
Crop Genetics and Production Research Unit, Box 345, Stoneville, MS 38776
* Corresponding author (abruns{at}ars.usda.gov).
Received for publication May 13, 2005. Corn (Zea mays L.) planting dates are regional and vary across the contiguous USA. Improved technologies allow corn to be planted earlier. The objective of this research was to evaluate the effects of planting date on the agronomics of Bt and non-Bt hybrids grown in the Mid-South. Twelve hybrids, two Bt [Bacillus thuringiensis (Berliner)], and two non-Bt for three maturity groups [short-season (11801270 GDU 10's), mid-season (14451470 GDU 10's), and full-season (15401625 GDU 10's)] were evaluated for GDU 10's at silking and physiological maturity, yield, yield components, and mycotoxins in 2002, 2003, and 2004 at Stoneville, MS. Plots were planted in a split-plot of a randomized complete block replicated four times and furrow irrigated. Whole plots were plantings in early April, late April, or mid-May, while subplots were hybrids randomly assigned. Experimental units were four 102-cm rows, 9.1 m long. Lodging and dropped ears were inconsequential. Yields were greater for both April plantings (8.6 and 9.2 Mg ha1 for early April and late April, respectively) than mid-May plantings (7.8 Mg ha1). Short-season hybrids generally yielded less than mid-season or full-season hybrids. The Bt hybrids yielded more than non-Bt hybrids (9.1 Mg ha1 vs. 7.9 Mg ha1, respectively). Yields correlated with GDU 10's at silking [yield = 0.037x 20.416 (r = 0.77)] but not physiological maturity. Aflatoxin was high in 2002 (224.0 mg Mg1), and much less (28.8 and 7.4 mg Mg1) in 2003 and 2004, respectively. The Bt hybrids had less fumonisin contamination than non-Bt hybrids (5.2 mg kg1 vs. 8.5 mg kg1) but less aflatoxin only in 2003 (12.4 mg Mg1 vs. 45.3 mg Mg1).
Abbreviations: GDU 10, growing degree unit based on 10°C
This article has been cited by other articles:
![]() |
H. A. Bruns A Survey of Factors Involved in Crop Maturity Agron. J., January 8, 2009; 101(1): 60 - 66. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. J. Kucharik Contribution of Planting Date Trends to Increased Maize Yields in the Central United States Agron. J., February 26, 2008; 100(2): 328 - 336. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. R. Capristo, R. H. Rizzalli, and F. H. Andrade Ecophysiological Yield Components of Maize Hybrids with Contrasting Maturity Agron. J., June 26, 2007; 99(4): 1111 - 1118. [Abstract] [Full Text] [PDF] |
||||
![]() |
X. Y. Sha and S. D. Linscombe Planting Date Affects Grain and Milling Yields of Water-Seeded Clearfield Rice Agron. J., June 26, 2007; 99(4): 1143 - 1150. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. J. Kucharik A Multidecadal Trend of Earlier Corn Planting in the Central USA Agron. J., October 3, 2006; 98(6): 1544 - 1550. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. F. Stanger and J. G. Lauer Optimum Plant Population of Bt and Non-Bt Corn in Wisconsin Agron. J., June 5, 2006; 98(4): 914 - 921. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| The SCI Journals | Crop Science | Vadose Zone Journal | |||
| Journal of Natural Resources and Life Sciences Education |
Soil Science Society of America Journal | ||||
| Journal of Plant Registrations | Journal of Environmental Quality |
The Plant Genome | |||