Experimental Procedures for Soybean Early Season Insect Control Test – Prosper, TX (planted 28 April 2000)

The soybean early season insect control test was conducted in Prosper, TX. The study was designed to determine whether in-furrow insecticide treatment or early-season foliar insecticide treatments for thrips and three-cornered alfalfa hoppers affect soybean yield in Northeast Texas. On 28 April, Garst D421STS/N was planted on 40-inch rows. Plots were eight rows wide by 40 feet long. Soil type was a Houston Black Clay with pH 8.3. The seeding rate was 150,000 seed per acre. Plots were replicated four times in a randomized complete block design and divided into four treatments:

1. Check
2. A Threshold Spray of 0.2 lb Orthene/acre (0.18 lb a.i.)
3. An Automatic Spray of 0.2 lb Orthene/acre (0.18 lb a.i.)
4. Temik at 7 lbs/acre (1.05 lbs a.i./acre).

The automatic spray was applied twice, regardless of insect populations, while the threshold spray was applied when thrips density reached 2 per plant (once on 25 May). Temik was applied in-furrow at planting. Rain prevented application of Orthene until 25 May, but thrips sampling was performed on 16 May, 22 May, and 30 May. No rain was received in July or August. Plots were end trimmed to 30 feet and rows 5 and 6 were harvested for yield. See results below.
 
Treatment
Yield (bu/acre)
Check
18
Orthene - threshold
17
Orthene - automatic
16
Temik
15
LSD (0.05)
3

 
 
 
 
 
 
 
 
 
 
 
 
 
 

Acknowledgements

We thank Garst Seed Co. for supplying the seed, Cell-Tech 2000 (Lipha-Tech, Inc.) for the inoculant, and the Texas Soybean Board for funding the project.

Fungicide Tests

Both conventional and experimental seed treatments were tested at two locations (Prosper and Telephone, TX) using Garst D485. Planting dates were early April and in all, six treatments and a check were included. Although minor differences in plant stands were found, no yield differences were found at either location.

Uniform IV-South Test

Sixteen entries from southern breeding programs were planted on 25 April 2000 at Cooper, TX. Yields ranged from 25 to 10 bushels per acre. Results are can be obtained from Gary Shelton, USDA-ARS in Stoneville, MS.