Performance of sugarbeet hybrids with sugarbeet root maggot rrsistant pollinators

Authors: Campbell, Larry; MILLER, J - BETASEED INC; REJISJE, M - BETASEED INC; SMITH, L - UNIV OF MN CROOKSTON

Submitted to: Plant Breeding
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/13/2007
Publication Date: 1/7/2008
Citation: Campbell, L.G., Miller, J., Rekoske, M., Smith, L.J. 2008. Performance of sugarbeet hybrids with sugarbeet root maggot resistant pollinators. Plant Breeding. 127:43-48.

Interpretive Summary: Sugarbeet root maggot is a major insect pest of sugarbeet throughout much of North America. Germplasm lines with root maggot resistance are available, but information on the root maggot resistance of hybrid cultivars created by crossing these lines with a susceptible parental line is lacking. This study compared the performance of four hybrids with resistant pollinators to two susceptible hybrids, with and without insecticide, in four environments. In all environments, the hybrids with the resistant pollinators and no insecticide had root yields equal to or greater than the susceptible commercial hybrid with insecticide. In two environments, the root yields of the susceptible hybrids were low and the difference between the root yields with and without insecticide were relatively small, indicating the insecticide was ineffective. In contrast, the root yields of the resistant hybrids, with or without insecticide, in these trials were substantially higher than the susceptible hybrids and similar to corresponding root yields at the other sites. Based upon these trials, it appears that hybrids produced with the currently available resistance sources would have sufficient resistance to prevent catastrophic yield reductions due to root maggot feeding, could reduce uncertainty caused by fluctuations in insecticide effectiveness, would provide protection against the development of insecticide resistant root maggot strains, and also provide a useful level of root maggot protection, if the current insecticides were no longer available.

Technical Abstract: Sugarbeet root maggot (Tetanops myopaeformis) is a major insect pest of sugarbeet (Beta vulgaris L) throughout much of North America. Two insecticides with similar mode of action are used almost exclusively for root maggot control. Alternative control strategies would be required if insecticide resistant root maggot developed or the insecticides were no longer available due to regulatory actions. Germplasm lines with root maggot resistance are available, but information on the root maggot resistance of hybrid cultivars created by crossing these lines with a susceptible cms parental line is lacking. This study compared the performance of four hybrids with resistant pollinators to two susceptible hybrids, with and without insecticide, in four environments. In all environments, the hybrids with the resistant pollinators and no insecticide had root yields equal to or greater than the susceptible commercial hybrid with insecticide. In two environments, the root yields of the susceptible hybrids were low and the difference between the root yields with and without insecticide were relatively small, indicating the insecticide was ineffective. In contrast, the root yields of the resistant hybrids, with or without insecticide, in these trials were substantially higher than the susceptible hybrids and similar to corresponding root yields at the other sites. Based upon these trials, it appears that hybrids produced with the currently available resistance sources would have sufficient resistance to prevent catastrophic yield reductions due to root maggot feeding, could reduce uncertainty caused by fluctuations in insecticide effectiveness, would provide protection against the development of insecticide resistant root maggot strains, and also provide a useful level of root maggot protection, if the current insecticides were no longer available.