Can you pass muster when it comes to understanding how corn grows, and how to manage it most effectively? Here's your chance to find out. Try the second half of our quiz, based largely on information in Purdue University's unique Corn and Soybean Field Guide. (For the first part of the quiz, see page 14 in the January 2006 issue.)
Determine if it is true or false:
1. The more nitrogen you apply up to 300 pounds per acre, the more corn will yield, no matter the hybrid. T F
2. The long-term recommendation of 1.2 pounds of nitrogen applied per bushel of corn produced may be higher than necessary. T F
3. Once the growing point is above the ground, a hard freeze will not injure corn plants. T F
4. Atrazine was recently reregistered as a corn herbicide by the U.S. EPA with certain restrictions. T F
5. The most important element in starter fertilizer in no-till corn is potassium. T F
6. Anhydrous ammonia contains 82% actual nitrogen by weight. T F.
7. Regular, 8-inch-depth soil tests for nitrogen in Indiana are unreliable. T F
8. Soil test values for phosphorus and potassium are no longer valid after one season. T F
9. Lightning corn hybrids are tolerant to Roundup. T F
10. Clearfield corn is a non-GMO trait. T F
11. YieldGard Bt corn-borer resistance was introduced before YieldGard rootworm traits. T F
12. Rootworm larvae seldom move more than 30 inches form where they hatch. T F
13. Readings of 10 degrees above zero F at least once during the winter would wipe out overwintering corn borers. T F
14. Poncho 250 corn is treated with a low-level insecticide that controls wireworms and other secondary pests. T F
15. Landec Intellicoat corn is treated with a polymer and designed for very early planting. T F
16. High-mag lime is high in calcium contest. T F
17. Pel lime is simply finely ground ag lime. T F
18. Dolomitic lime contains large amounts of magnesium compared to normal ag line. T F
19. Soil tests of 5.5 to 5.7 pH are adequate for growing alfalfa. T F
20. New Roundup Ready alfalfa can be sprayed with glyphosate herbicide. T F
21. Cation exchange capacity is a measure of a soil's nutrient-holding capacity. T F
22. Muck soils contain 30% to 80% organic matter. T F
23. Sandy soils are not subject to soil compaction. T F
24. A disk is more likely to compact soil than a field cultivator. T F
25. It takes more lime to raise pH from 5.5 to 6.5 in a clay soil compared to a sandy loam. T F
Answers: (1) False (2) True (3) False (4) True (5) False, nitrogen (6) True (7) True (8) False (9) False, Lightning herbicide (10) True (11) True (12) True (13) False (14) True (15) True (16) False, high in magnesium (17) True (18) True (19) False, 6.5 or higher (20) True (glyphosate is active ingredient in Roundup) (21) True (22) True (23) False (24) True (25) True
Where do you rank?
25 correct: Corn wizard!
15 to 24 correct: Good enough to grow high yields.
10 to 15 correct: You'd better bone up on corn.
5 to 9 correct: Where did you get those corny answers?
None correct: You know more about corn-pone than corn!