The results for four Licking Co. soybean fields are in Table 1. Germination and early growth conditions were extremely dry in 1994; therefore, no slug injury was detected in the comparisons on Table 1. Treatment rate on treated plots was approximately 10 pounds of 4% metaldehyde bait per acre, but varied greatly due to the difficulty of getting the material through a grain drill. Due to the dry conditions, no differences were found between the treated and untreated plots.
Table 2 shows results where plots were treated at planting time with rates of 0, 5, 7.5, and 10 pounds of 4% metaldehyde bait, as well as one plot with 10 pounds of 4% metaldehyde granule. Again, due to the dry conditions, no differences were found in plant population between treated and untreated plots. Dead slugs were observed on the treated plots, but before the crop emerged.
Table 3 shows results where two out of 6 corn rows were "swept" with "row sweepers, residue managers", etc. and sections in the field were treated with a 0, 5, or 10 pound rate of 4% metaldehyde bait at planting time. Considering primarily the June 11 data, it appears that removing residue from the rows gave a stand advantage, but that the at planting bait treatment had no effect. In plots on the same farm the previous year (when slug damage was much more prevalent due to the cool wet weather during germination), slug damage was lower, plant height taller, and stand greater on swept rows. This year, the plant stand was higher in swept rows, but plant height was no different. Yield was not compared this year, as it seemed apparent that the stand difference was not enough to influence yield.
Table 1 - Results from four Licking County Soybean Fields.
| Date of Observations | |||
|---|---|---|---|
| Observation | 2 June | 9 June | 16 June |
| Williams Farm | |||
| Crop Development | emerging | 3" or less | 4" or less |
| Prevailing Temp. & Moisture | 78 degrees dry | mod dry | 80 degrees dry |
| Stand per 50 row ft. Treated | n.a. | 88 | 90 |
| Stand per 50 row ft. Untreated | n.a. | 133 | 134 |
| Slug Injury | none | none | none |
| Lamp Farm | |||
| Crop Development | emerging | 3" or less | 4" or less |
| Prevailing Temp. & Moisture | 78 degrees dry | mod dry | 80 degrees dry |
| Stand per 50 row ft. Treated | n.a. | 141 | 141 |
| Stand per 50 row ft. Untreated | n.a. | 133 | 137 |
| Slug Injury | none | none | none |
| Branstool Farm | |||
| Crop Development | emerging | 2.5" or less | 3" or less |
| Prevailing Temp. & Moisture | 78 degrees dry | mod dry | 85 degrees adequate |
| Stand per 50 row ft. Treated | n.a. | 131 | 132 |
| Stand per 50 row ft. Untreated | n.a. | 108 | 107 |
| Slug Injury | none | none | none |
| Newell Farm | |||
| Crop Development | emerging | 3" or less | 4" or less |
| Prevailing Temp. & Moisture | 80 degrees dry | mod dry | 85 degrees very wet |
| Stand per 50 row ft. Treated | n.a. | 161 | 1551 |
| Stand per 50 row ft. Untreated | n.a. | 144 | 144 |
| Slug Injury | none | none | none |
| 1 - Storm and standing water may have resulted in inaccurate count. | |||
Table 2. - Fairfield soybean plot results at Brandt Farm.
| Dates of Observation | |||||
|---|---|---|---|---|---|
| 11 June | 28 June | ||||
| Treatment | Population | New Leaf Damage | Population | New Leaf Damage | |
| % | % | ||||
| No Bait | 50,500 | 93 | 94,500 | 79 | |
| 10 lbs. granule | 55,000 | 91 | 103,000 | 88 | |
| 10 lbs. molasses bait | 72,500 | 97 | 121,000 | 87 | |
| No bait | 74,500 | 95 | 116,000 | 87 | |
| 7.5 lbs. molasses bait | 78,500 | 100 | 128,000 | 87 | |
| 5 lbs. molasses bait | 45,000 | 100 | 77,000 | 91 | |
| No bait | 32,500 | 100 | 70,500 | 94 | |
Table 3. - Fairfield corn plot results at Brandt Farm.
| Dates of Observations | ||||||
|---|---|---|---|---|---|---|
| Treatment | 24 May | 11 June | 28 June | |||
| lbs. of bait | With Sweep | No Sweep | With Sweep | No Sweep | With Sweep | No Sweep |
| Population | ||||||
| 0 | 23,900 | 17,400 | 27,350 | 23,400 | 26,700 | 23,000 |
| 5 | 22,440 | 19,200 | 25,100 | 20,700 | 25,200 | 20,700 |
| 10 | 23,100 | 18,300 | 26,500 | 21,250 | 26,000 | 21,250 |
| Percent New Leaf Damage | ||||||
| 0 | 59 | 62 | 68 | 65 | 15 | 8 |
| 5 | 57 | 51 | 57 | 64 | 12 | 14 |
| 10 | 55 | 59 | 65 | 59 | 10 | 12 |
| Comments | ||||||
| Corn still emerging | Uniform height | Corn 36" tall | ||||
| regardless of | No slug damage | |||||
| Treatment | on new growth | |||||
Related Literature:
Studies in the northern corn belt have shown an advantage in using "row sweepers" to enhance early growth of corn: Iowa (Kaspar, Erbach and Cruse, 1990), removing residue from the row in continuous corn significantly increased plant height, decreased days to 50% emergence and days to 50% tassel, decreased grain moisture at harvest, reduced barrenness, and increased grain yield by 5 bushels/acre. Minnesota (Moncreif, Wagar and Kuznia, 1989-91 and Moncreif, Wagar and Kuznia, 1986-90) concluded that residue cover in the row of more than 20% was likely to lower yields in years with wet springs. Also in MN, Swan, Schneider, Noncreif, Paulson and Peterson, 1987, concluded that in row residue delayed emergence and corn plant development.
However, further south, results form residue removal or strip tillage have been mixed: Kentucky (Murdock, Herbck and Gray, 1992) obtained better plant stands and yields with strip preparation in one out of four years. Indiana (West, Griffith and Hill, 1992) concluded that strip preparation was generally not beneficial where standard no-till planting was previously successful. Ohio (Skeeles, Willson and Brandt, 1993) found that in a cool wet spring where no-till corn was planted into heavy residue with heavy slug populations, that rows with residue removed had better plant stand, were taller, and had less slug damage. However, no yield advantage was demonstrated.
Extension Program Implementation:
Results will be integrated into a summary of similar plots conducted around Ohio to evaluate the effectiveness of the metaldehyde bait. Also, two twilight tours were held on the plots. Results were presented at local summer field days and will be presented at winter meetings. Results were also published in the popular press.
References:
Kaspar, T.C., D.C. Erbach and R.M. Cruse. 1990. Corn response to seed-row residue removal. Soil
Science Society of America Journal 54: 1112-1117.
Moncreif, J.F., S.D. Grosland and J.J. Kuznia. Annual Reports. 1989-91. Tillage effects on corn growth, stand establishment and yield, Isanti County, MN: In: A Report on Field Research in Soils. Minnesota Agricultural Experiment Station, University of Minnesota, St. Paul, MN.
Noncreif, J.F., T.L. Wagner and J.J. Kuznia. Annual Reports. 1986-90. Tillage system and cultivation effects on corn growth and yield on a well-drained silt loam soil. In: A Report on Field Research In Soils. Minnesota Agricultural Experiment Station, University of Minnesota, St. Paul, MN.
Murdock, L.W., J.H. Herbck and T. Gray. 1992. Row cleaners in no-till corn production. In: Proceedings, Annual Purdue University Indiana Plant Food and Agricultural Chemicals Conference. Purdue University, Department of Agronomy, West Lafayette, IN.
Swan, J.B., E.C. Schneider, J.F. Noncreif, W.H. Paulson, and A.E. Peterson. 1987. Estimating corn growth, yield, and grain moisture from air growing degree days and residue cover. Agronomy Journal 79: 53-60.
West, T.D., D.R. Griffith and P.R. Hill. 1992. Strip preparation study. In: Tillage Research Annual Report. Purdue University, Department of Agronomy, West Lafayette, IN.
Return to Ohio IPM Home Page.