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Submitted to: Plant Management Network
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 7/7/2006 Publication Date: 10/7/2006 Citation: Sorensen, R.B., Lamb, M.C., Butts, C.L. 2006. Row pattern, plant density, and nitrogen rate on corn yield in the southeast. Plant Management Network. doi:10.1094/CM-2006-1211-01-RS. Interpretive Summary: It is recommended that peanut be raised using twin-row patterns for higher yield and reduced Tomato Spotted Wilt Virus (TSWV) incidence. However, most peanut growers also raise corn. This would imply that growers would need both a single and twin row planter for these respective crops. Nitrogen is the limiting nutrient for corn production. Supplying nitrogen through a subsurface drip irrigation system has been quite successful in other regions and on various crops. Therefore, the objectives of this research were to compare corn grain yield when planted in single and twin row patterns at various plant densities and with two nitrogen rates. The research design was a split plot randomized design with three replications per treatment. The main split was for nitrogen where one block received the recommended rate of nitrogen and the other block received twice the recommended rate (R2). The single row pattern has rows that are 36 inches apart. The twin-row pattern has the outsides rows at 36 inches apart, the inside rows are 18 inches apart with the twin rows being 9 inches apart. Corn was planted in a single row (S1) and twin-row (T1) pattern at 3.3 seeds/ft with the high plant density being planted in twin rows (T2) at 6.6 seeds/ft. About 25 lbs N/ac were applied preplant along with the recommended rate of other nutrients as recommended by soil testing. The rest of the nitrogen was supplied through the drip system at 10 to 15 day increments at 25 to 50 lbs N/ac not to exceed 150 and 300 lbs N/ac in the respective blocks. The single (S1) and twin-row (T1) had the same corn grain yield (8 961 lbs/ac), stalk diameter (0.71 in), and seed test weight (54.4 lbs/bu). The twin-row (T2) with the higher plant density had lower grain yield (6 201 lbs/ac) and smaller stalk diameter (0.50 in) compared with single (S1) and twin row (T1) recommended plant density. Increased nitrogen did not affect grain yield or stalk diameter, but did increase grain test weight. Seed cost for the twin-row R2 was double the cost of single or twin-row R1. Percentage of cost per gross revenue for single and twin R1 was 8% compared with 30% for twin-row R2. Overall, this research shows that corn can be planted in a twin-row pattern without loss of yield or gross revenue provided the plant population is held at the recommended rate. Thus, a grower can use the same planter for corn and peanut and would not need to purchase two planters, i.e., one single row and one twin row to plant his crops. Technical Abstract: It is uncertain how corn (Zea mays L.) yield would be affected by planting in a twin-row orientation in the southeast. The objectives were to compare corn grain yield when: 1) planted in single and twin-rows, 2) plant densities at recommended (1R) and twice the recommended (2R) rate, and 3) nitrogen rates of 168 and 336 kg N/ha. Corn was irrigated using a subsurface drip irrigation system. The single and twin-row with 1R seed density had the same corn grain yield (10069 kg/ha), stalk diameter (18.1 mm), and test weight (700 kg/m). Twin-row 2R had lower grain yield (6967 kg/ha) and smaller stalk diameter (12.8 mm) compared with single or twin row 1R. Increased nitrogen did not affect grain yield or stalk diameter, but did increase grain test weight. Seed cost for the twin-row R2 was two times that of single or twin-row R1. Seed cost percentage of gross revenue for single and twin R1 was 8% compared with 30% for twin-row R2. Overall, this research implies corn can be planted in a twin-row pattern without loss of yield or gross revenue provided the plant population does not exceed the recommended rate. |
