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 : 12

Rotylenchulus reniformis field evaluation

At TVREC, the combination of a nematicide ST + (NH4)2SO4 + Vydate® C-LV + Max-In® Sulfur at PHS was the most effective at increasing root fresh weight from sample data combined at PHS + FB. A nematicide ST + (NH4)2SO4 + Vydate® C-LV + Max-In® Sulfur at PHS and FB had the lowest R. reniformis eggs per gram of root, closely followed by the combination of a nematicide ST + (NH4)2SO4 + Vydate® C-LV at PHS. These findings are supported by Badra and Elgindi (1979), where foliar applications of Vydate® C-LV significantly reduced R. reniformis population levels. Similarly, the use of a nematicide ST COPeO™ Prime (Fluopyram) inhibited R. reniformis from increasing on cotton root systems ( Faske and Hurd, 2015). The combination that supported the largest lint yield was a nematicide ST + (NH4)2SO4 + Vydate® C-LV at PHS. Nematicide applications were analyzed individually in response to lint yield. An application of a nematicide ST increased overall yield by 11%. A trial conducted by Groover et al. (2020) supports this conclusion and found that a nematicide ST (COPeO™ Prime) increased lint yield by 14%. A single foliar application of Vydate® C-LV increased overall lint yield by 13%, while two applications of Vydate® C-LV increased overall lint yield by 2%. Increases in yield with single or multiple Vydate® C-LV applications on cotton were also found in a study conducted by Hammes et al. (1999).

The combination with the largest mean profit in dollars/ha was a nematicide ST + (NH4)2SO4 + Vydate® C-LV at PHS. This combination also supported the largest lint yield. Based on the lower and upper profits, there is a 90% chance when using this fertilizer and nematicide combination in a R. reniformis infested field, the mean profit will fall between $991.15/ha and $1360.59/ha. The increased mean profit of this combination could be contingent on the moderate fertilizer and nematicide input costs. The overall input cost of this combination was $55.96/ha which was $46.17 cheaper than the most expensive (NH4)2SO4 based combination. This evaluation is supported by Zimet et al. (2002) who reported financial returns in R. reniformis fields with lower chemical rates equating to reduced chemical input costs. Similarly, a study conducted by Koenning et al. (2007) saw an increase in yield with the use of nematicides in R. reniformis infested fields but when conducting an economic analysis determined the profit from the additional yield did not cover the increased chemical costs.