1. Sorghum – Sugarcane Aphid Research Exchange Meeting
Impact of insecticide seed treatments, tolerant sorghum varieties, and planting date on population growth of sugarcane aphid and sorghum yield in the Texas Panhandle
Ada Szczepaniec
Texas A&M AgriLife
Sorghum – Sugarcane Aphid Research Exchange Meeting
Dallas, TX, January 3 – 4, 2017

2. Introduction
SCA in High Plains: timing of colonization, effectiveness of thresholds established in the South
The goal of this research was to establish how
planting date,
insecticide seed treatments, and
sorghum varieties
affected colonization and population growth of sugarcane aphid (SCA) and sorghum yield.

3. Materials & Methods
Replicated plots (8 rows by 50’) in Bushland, TX– each treatment was replicated four times for early and common planted sorghum
Plots were scouted for aphids twice each week; once aphids colonized sorghum their density per leaf was established
Insecticide (Sivanto® at 4 oz/A) was applied once densities reached the aphids per leaf threshold
Sorghum were harvested from a portion of each plot to estimate yield

4. SCA Densities in Early Planted Sorghum (Treated)
SCA/leaf

5. SCA Densities in Sorghum (Treated)
Tolerant variety with insecticide seed treatment had the fewest SCA. Effective suppression was achieved when insecticide applied at SCA/leaf.

6. No significant differences in yield between varieties regardless of seed treatment in early-planted sorghum

7. In absence of foliar insecticide treatments tolerant variety yielded better than susceptible

8. Tolerant variety had higher yield than susceptible var.

9. *

10. Key Learnings
Planting date affects SCA densities post-insecticide treatments, yield
Seed treatments had an impact on SCA and on yield when sorghum planted at common planting date
Tolerant variety had significant effect on SCA densities and yield
Using threshold of SCA/leaf allowed for successful suppression of aphids

11. Next Steps Repeat experiments in 2017
Expand number of tolerant variants
Evaluate economic threshold of SCA (post-bloom sorghum)