Cherry R.,Everglades Research and Education Center
Florida Entomologist | Year: 2011
The parasitic wasp Eumicrosoma benefica has year round activity and was found at all southern chinch bug infestations that were sampled in southern Florida. This parasite is an important, if not the most important, biological control agent in reducing southern chinch bug populations in southern Florida.
Odero D.C.,Everglades Research and Education Center |
Mesbah A.O.,Powell Research and Extension Center |
Miller S.D.,University of Wyoming |
Kniss A.R.,University of Wyoming
Weed Science | Year: 2011
Redstem filaree is a troublesome weed for sugarbeet growers in northern Wyoming and southern Montana. Field studies were conducted in Powell, WY, in 2006 and 2008 to determine the influence of season-long interference of various redstem filaree densities and the duration of interference on sugarbeet. Root and sucrose yield decreased with increasing redstem filaree density. The rectangular hyperbola model with the asymptote (A) bounded at 100% maximum yield reduction characterized the relationship between redstem filaree density and sugarbeet yield reduction. The estimated parameter I (percent yield reduction per unit weed density as density approaches zero) was 5% for root and sucrose yield reduction. Sugarbeet root yield decreased as the duration of redstem filaree interference increased. The critical timing of redstem filaree removal to avoid 5 and 10% root yield reduction was estimated to be 25 and 32 d after sugarbeet emergence, respectively. Redstem filaree interference did not affect the sucrose content percentage. These results demonstrate that redstem filaree is competitive with sugarbeet and should be managed appropriately to reduce negative effects on yield.
Wang Y.,Texas AgriLife Research Center |
Wang Y.,Everglades Research and Education Center |
Pinson S.R.M.,U.S. Department of Agriculture |
Fjellstrom R.G.,U.S. Department of Agriculture |
Tabien R.E.,Texas AgriLife Research Center
Molecular Breeding | Year: 2012
F2:3 families from crosses between three rice indica introgression lines and their common japonica recurrent parent were used to evaluate two quantitative trait loci (QTL) for sheath blight (SB) resistance. Three selected TeQing-into-Lemont backcross introgression lines (TILs) were more resistant than their susceptible parent (Lemont) in inoculated field plots, and were molecularly verified to contain TeQing alleles at qSB9-2 and/or qSB12-1. F2 individuals homozygous for qSB9-2 and qSB12-1 provided F2:3 families that fit four genotypic classes: containing the resistant TeQing allele for qSB9-2 TQ alone, qSB12-1 TQ alone, both qSB9-2 TQ and qSB12-1 TQ, and neither SB QTL introgression. By comparing the SB resistance of these four genotypic classes in micro-chamber evaluations and inoculated field plots, the phenotypic values of the QTL were measured. Under both study conditions, disease resistance ranked qSB9-2 + qSB12-1 > qSB9-2 > qSB12-1 > no QTL, with both qSB9-2 and qSB12-1 acting as dominant resistance genes. In micro-chamber studies, qSB9-2 TQ reduced disease an average of 1. 0 disease index units and qSB12-1 TQ by 0. 7 using a scale of 0-9. Field effects of qSB9-2 TQ and qB12-1 TQ were less pronounced, with average phenotypic gains of 0. 5 and 0. 2 units, respectively. TIL:642 proved to contain qSB9-2 TQ in an introgression so small it was tagged by just RM205 on the tip of chromosome 9. These studies verify that the indica introgression of qSB9-2 TQ or qSB12-1 TQ can measurably improve resistance to sheath blight disease in a highly susceptible tropical japonica cultivar, and fine-mapped the qSB9-2 locus. Markers presently verified as linked to these QTL can support marker-assisted breeding to improve disease resistance. © 2011 Springer Science+Business Media B.V. (outside the USA).
Cherry R.,Everglades Research and Education Center |
Nuessly G.,Everglades Research and Education Center
Florida Entomologist | Year: 2010
The neem tree Azadirachta indica A. Juss produces numerous allelochemical compounds. The most effective active ingredient in A. indica based insecticides is azadirachtin. We found that azadirachtin did not cause mortality, antifeeding responses, or change growth rate of Melanotus communis (Gyllenhal) wireworms. However, azadirachtin treated soil was repellent to the wireworms. This is the first report of azadirachtin being repellent to any of the large and economically important family of Elateridae.
Cherry R.,Everglades Research and Education Center |
Grose P.,King Ranch |
Barbieri E.,King Ranch
Journal of Pest Science | Year: 2013
Wireworms in Florida are primarily a pest in newly planted sugarcane, and growers usually apply a soil insecticide at planting to protect germinating seedpieces from wireworm damage. However, studies have suggested that this application in many cases may not be necessary. The objective of this research was to test a sequential sampling method to determine the need for soil insecticide at sugarcane planting. Testing was conducted on fields located on King Ranch near South Bay, Florida. Wireworm samples were taken in a transect across the length of each field. We used an economic injury level of nine or more wireworms per 25 samples. Sugarcane yield parameters for each whole field were obtained through standard commercial harvesting procedures. Using our sampling method, 38 fields were judged as not needing insecticide application. There was no significant difference in yield in these fields with versus those without insecticide application. © 2011 Springer-Verlag.