|St Martin, S|
Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/21/2000
Publication Date: N/A
Citation: Interpretive Summary: When soybean yields ranged from 15 bushels/acre to 40 bushels/acre, a single soybean variety could be developed that would produce the highest yield across this range of yield levels. However as soybean yields have increased to 50, 60 and 70 bushels/acre or more, it has become increasingly more difficult to produce a single variety that is highest in yield over this entire yield range. Such broadly adapted varieties tend to be too tall (produce too much vegetative growth) in high yield environments and tend to fall over (lodge). This lodging interferes with photosynthesis, reducing the yield potential and can cause harvesting problems and seed loss. In the lower yielding environments, broadly adapted varieties which have been selected for shorter plant height to prevent lodging, tend to be too short for best yields. Thus to over come this problem, determinate semidwarf varieties have been developed with specific adaptation to high yield environments. These varieties are much shorter than the traditional indeterminate varieties that have been selected for broad adaptation and are recommended for planting only on soils with a history of high yields (50 bushels/acre or higher). In these environments the semidwarf varieties can significantly out yield the taller indeterminate varieties which frequently become severely lodged. Troll is a new determinate semidwarf soybean variety adapted to the southern portion of the corn belt states, released in 1998, which has shown excellent yield potential in high yield environments.
Technical Abstract: Troll is a maturity group IV determinate semidwarf variety released in 1998. It is a F4-derived lline, originally designated as HC90-196, from the cross Sprite 87 x HC80-1756. HC80-1756 is a determinate semidwarf line from the cross, Miller 67 x Williams. Miller 67 is a determinate, maturity group III variety introduced from Korea in 1967 by a farmer, Richard Miller, from Arcanum, OH. Troll has averaged 10% to 15% higher yield than the maturity group IV determinate variety, Ripley, currently being grown. Like all semidwarf varieties, Troll is recommended only on soils with a history of high yields (>3300 kg/ha) and it should be solid-seeded in 17- to 20cm row spacing at a seeding rate of 750,000 seeds/ha of 90+% germination (675,000 viable seed/ha).