Table 3.
Half-lives (t1/2), empirical rate constants (k), and equations for changes in neonicotinoid concentrations on soybean treated with imidacloprid (IMI) as the primary treatment and clothianidin as a second treatment (CLO2), and corn with either thiamethoxam (TMX) or clothianidin (CLO1). Seeds were placed on the soil surface in the environment for 30 days during May – June in 2016 and 2017 in Minnesota, USA. Equations for CLO1 in 2016 are not provided because no seeds remained on the soil surface after 30 days.
| Chemical | Seed type | Seed color | t1/2 (days) |
k | Equation, R2 both years | Equation, R2 2016 |
Equation, R2 2017 |
|---|---|---|---|---|---|---|---|
| IMI | soybean | red | 4.7 | 0.149 | 729.66e−0.149× R2 = 0.88 | 1006.6e−0.13× R2 = 0.99 | 528.92e−0.168× R2 = 0.97 |
| TMX | corn | red | 3.6 | 0.193 | 536.89e−0.193× R2 =0.80 | 794.66e−0.223× R2 = 0.86 | 362.73e−0.163× R2 = 0.76 |
| CLO1 | corn | purple | 2.0 | 0.352 | 2195.8e−0.352× R2 = 0.85 | NA | 689.17e−0.138× R2 = 0.98 |
| CLO2 | soybean | red | 2.3 | 0.305 | 39.464e−0.305× R2 =0.86 | 82.923e−0.354× R2 = 0.86 | 18.782e−0.256× R2 = 0.96 |