Rotylenchulus reniformis

Gordon, Kara L, Schrimsher, Drew W & Lawrence, Kathy S, 2022, Additional fertilizer and nematicide combinations on upland cotton to manage Rotylenchulus reniformis and Meloidogyne incognita in Alabama, Journal of Nematology 54 (1), pp. 1-15 : 7-8

Rotylenchulus reniformis field evaluation

Plant stand was not affected by the additional fertilizer or Vydate ® C-LV combinations ( Table 4). The additional fertilizer and nematicide combinations did not significantly increase root fresh weight at PHS + FB. Rotylenchulus reniformis eggs per gram of root were not significantly decreased when sampled at PHS + FB. The combination of a nematicide ST + (NH 4) 2 SO 4 + Vydate ® C-LV + Max-In ® Sulfur at PHS and FB had the lowest R. reniformis eggs per gram of root when sampled at PHS + FB. The combination of a nematicide ST + (NH 4) 2 SO 4 + Vydate ® C-LV at PHS supported a significantly larger lint yield than the treatments with no nematicide ST, which applied (NH 4) 2 SO 4 at PHS, 28-0-0-5 at PHS and the combination of a nematicide ST + 28-0-0-5 at PHS and FB (P ≤ 0.10). Lint yield was increased by 546 kg /ha, 603 kg /ha, 580 kg /ha or 31%, 34% and 33% with the combination of a nematicide ST + (NH 4) 2 SO 4 + Vydate ® C-LV at PHS when compared to the three lowest yielding combinations, (NH 4) 2 SO 4 at PHS, 28-0-0-5 at PHS and a nematicide ST + 28-0-0-5 at PHS and FB.

Mean profits for fertilizer applications of (NH 4) 2 SO 4 and 28-0-0-5 at PHS with no nematicides averaged $853.62 ( Table 5). A nematicide ST with an additional fertilizer application at PHS increased mean profit by $46/ha from an additional fertilizer alone. A ne-

No Treatmentsy

1 (NH4)2SO4 – PHS

2 28-0-0-5 – PHS

3 STu + (NH4)2SO4 – PHS

4 ST + 28-0-0-5 – PHS

5 ST + (NH4)2SO4 – PHS + FB

6 ST + 28-0-0-5 – PHS + FB

7 ST + (NH4)2SO4 + Vydate® C-LV – PHS

8 ST + 28-0-0-5 + Vydate® C-LV – PHS

9 ST + (NH4)2SO4 + Vydate® C-LV + Max-In®

Sulfur – PHS 10 ST + 28-0-0-5 + Vydate® C-LV + Max-In®

Sulfur – PHS

11 ST + (NH 4) 2 SO 4 + Vydate ® C-LV + Max- In ® Sulfur – PHS + FB

12 ST + 28-0-0-5 + Vydate ® C-LV + Max-In ® Sulfur – PHS + FB

Root fresh R. reniformis

Lint Standx weigh (g) eggs/g root

(kg/ha) PHSw + FBv PHS + FB

59 14.78 5723 1257 bz

56 14.26 6821 1200 b 57 16.11 4735 1345 ab

56 15.99 4354 1368 ab 56 15.63 3126 1566 ab

55 13.51 5140 1223 b 57 17.02 2558 1803 a 57 16.51 5393 1411 ab

58 16.91 5519 1542 ab

55 14.89 4156 1412 ab

58 16.02 2228 1432 ab

59 14.97 5670 1455 ab

Notes: zLS-means followed by the same letter are not significantly different at P ≤ 0.10 as determined by the

Tukey Kramer method. yAll DP 1646 B2XF seeds were pretreated with a BASF fungicide and insecticide metalaxyl, pyraclostrobin, myclobutanil, imidacloprid, and fluxapyroxad. xStand count is the number of seedlings per 7.6 m of row collected 14 DAP. wPHS refers to the pinhead square plant growth stage when the first additional combination of fertilizers and nematicides were applied. vFB refers to the first bloom plant growth stage when the second additional combination of fertilizers and nematicides were applied. uST refers to nematicide seed treatment, Aeris ® (Thiodicarb) applied in 2019 and COPeO ™ Prime(Fluopyram) applied in 2020.

maticide ST with an additional application of fertilizer at PHS and FB increased profit by $32/ha from an additional fertilizer alone. Combinations with Vydate ® C-LV applied at PHS had an increased profit of $137/ha from an additional fertilizer alone. Fertilizer and nematicide combinations that included Vydate ® C-LV at PHS and FB had an increased profit of $48/ha. All combinations were compared to the mean profit of treatments of an additional fertilizer with no nematicides to determine increased profit per hectare. The combination of a nematicide ST + (NH 4) 2 SO 4 + Vydate ® C-LV at PHS had the greatest overall mean profit of $1175.87 which was significantly greater than the mean profit of (NH 4) 2 SO 4 at PHS, 28-0-0-5 at PHS and a nematicide ST + 28- 0-0-5 at PHS and FB.