| |
| Web URL(s): | https://listings.lib.msu.edu/iowat/1991.pdf#page=56
Last checked: 01/10/2017
Requires: PDF Reader |
|---|
| Publication Type:
| Report |
|---|
| Author(s): | Lewis, D. R.;
Christians, N. E. |
|---|
| Author Affiliation: | Associate Professor, Extension Entomologist, Entomology Department; Professor, Turfgrass Science, Research and Teaching, Department of Horticulture, Iowa State University |
|---|
| Title: | Report of insecticide evaluation |
|---|
| Source: | 1991 Iowa Turfgrass Research Report. July 1991, p. 51-53. |
|---|
| Publishing Information: | Ames, Iowa: Iowa State University |
|---|
| Keywords: | TIC Keywords: Insecticides; White grubs; Insecticide evaluation
|
|---|
| Abstract/Contents: | "Damage to turfgrass by annual white grubs (Cyclocephala spp.) is a common, but spotty and locally severe problem in Iowa. Amount of damage varies greatly from place to place and year to year, depending on several factors such as grass variety, cultural maintenance practices, irrigation, and weather. Root feeding by these masked chafer larvae characteristically causes grass to wilt, turn tan, and finally die, usually in late August or early September. Several granular and sprayable insecticide products are registered for white grub control. Timing of insecticide application is very important in achieving effective control of white grubs before damage becomes severe. The objective of this study was to evaluate and compare the efficacy of several registered and experimental insecticides against annual white grubs infesting turfgrass. The study was conducted on a rough area of the Hyperion Field Club located in Johnston, Iowa (Polk County). The soil at the club is a Waukegan loam (fine silt over sandy, mixed, mesic typic Hapludoll) with 148 lb/a P, 480 lb/a K, and 5% organic matter. The plots were on an east-facing slope. The grass species in the plots were Kentucky bluegrass and a small amount of crabgrass. The rough was receiving low maintenance but regular mowing (at approximately 3 in) and irrigation as necessary. There was between 1/4 and 1/2 in of thatch at the test site. Grubs were present in the plot area at the time of insecticide application. Grass was very healthy and lush as a result of unprecedented rainfall during the first 8 months of 1990. The insecticide treatments were applied on August 16, 1990 except for the low rate of Gamma-Mean 400 (0.7 lb ai/a) which was applied on August 21, 1990. Grub population counts were made September 27, 1990. The experimental design consisted of 12 treatment plots and one untreated check plot, randomly assigned in each of three replications. Each plot consisted of a 5 ft2 area (25 ft2). All insecticides were applied at the rate specified on the manufacturer's label or product guidelines. Liquid and dry flowable insecticides were diluted with water. The Gamma-Mean 400 product was tank-mixed with a penetrant supplied by the manufacturer. Sprays were applied with a compressed gas, backpack sprayer connected to a hand-held, three-nozzle boom. The boom covered a 5 ft wide area, and diluted insecticide spray was applied to the test plots with alternating perpendicular passes over the treatment area. The amount of insecticides were premeasured into round, cardboard containers and applied uniformly over the plot by shaking through a perforated lid. The insecticides were watered into the turfgrass with approximately 1/2 in of irrigation. Annual white grub population counts were made five weeks after treatment by randomly selecting four sample sites within each plot and cutting an 8 in circular plug with a "large cup" cutter. The sod was removed from the cut area and the root mass carefully parted and examined for living grubs. The soil beneath the cut sod was scratched loose to a depth of 2 in and similarly examined. The total number of white grubs found in each sample was recorded. Population counts in the samples were converted to number of white grubs per square foot for analysis and reporting. The insecticides used in this project, formulation, rate of application, and mean number of white grubs per square foot are given in Table 25. Significant differences among treatmens and between treatments and the untreated check were difficult to determine because of very low numbers of white grubs in the untreated checks and variation in population density among replications. However, a nonrestricted least significant difference (LSD) test was done to examine for significant differences in the treatment plots. The average population density in the untreated check plots was only 1.9 white grubs per square foot. This is less than the population density threshold considered sufficient to cause damage in irrigated, healthy turfgrass. Indeed, the grass in the plots looked very good at the time of grub counting and root damage was very slight as evidenced by the strong root system connecting the cut plugs to the soil. In spite of the low white grub numbers, differences in product performance can be detected. The high rate of Triumph 4E, Chipco Mocap 5G, and the Oftanol 2E provided significant control. Population reduction just outside the significant range was achieved with Triumph 1G (both rates) and Pageant DF chlorpyrifos. The chlorpyrifos observation is interesting in light of poor performance of Dursban products in earlier trials at this golf course and frequent complaints about Dursban performance within the turfgrass industry. Products providing little or no control of white grubs included the low rate of Triumph 4E, Chipco Sevimol 4E, Gamma-Mean 400 (both rates), and Dylox SP." |
|---|
| Language: | English |
|---|
| References: | 0 |
|---|
| Note: | Article appears as abstract
Table |
|---|
| ASA/CSSA/SSSA Citation (Crop Science-Like - may be incomplete):
Lewis, D. R., and N. E. Christians. 1991. Report of insecticide evaluation. Iowa Turfgrass Res. Rep. p. 51-53. |
| Fastlink to access this record outside TGIF: https://tic.msu.edu/tgif/flink?recno=29306 |
| If there are problems with this record, send us feedback about record 29306. |
| Choices for finding the above item: |
|---|
| Web URL(s):
https://listings.lib.msu.edu/iowat/1991.pdf#page=56
Last checked: 01/10/2017
Requires: PDF Reader |
| 
MSU catalog number: SB 433 .A1 I55 |
| Request through your local library's inter-library loan service (bring or send a copy of this TGIF record) |
