Meloidogyne incognita

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 : 12-13

Meloidogyne incognita field evaluation

At PBU, the combination that supported the largest root fresh weight sampled at PHS + FB was a nematicide ST + (NH4)2SO4 at PHS. Meloidogyne incognita eggs per gram of root combined were lowest in the treatment combination of a nematicide ST + (NH4)2SO4 + Vydate® C-LV + Max-In® Sulfur at PHS. This combination decreased M. incognita eggs per gram of root by 15% when compared to the treatment of (NH4)2SO4 at PHS, with no nematicide. A study conducted by Faske and Hurd (2015) also found that a nematicide ST reduced M. incognita population levels when compared to treatments with only a base fungicide. The combination of a nematicide ST + 28- 0-0-5 + Vydate® C-LV + Max-In® Sulfur at PHS and FB was the most effective at increasing lint yield. This combination also supported the largest seed cotton yield in the M. incognita microplot trials in 2019 and 2020. The application of a nematicide ST (COPeO™ Prime) provided the greatest yield protection against M. incognita in trials conducted by Faske et al. (2021). This finding contrasts with Anderson et al. (2012) who found applications of Vydate® C-LV did not have an impact on cotton lint yield. Nematicide applications were analyzed individually to evaluate lint yield responses. The application of a nematicide ST increased overall lint by 20%, a single Vydate® C-LV application increased overall lint by 11%, and sequential Vydate® C-LV applications increased overall lint by 5%.

The largest mean profit was obtained with the combination of a nematicide ST + 28-0-0-5 + Vydate® C-LV + Max-In® Sulfur at PHS and FB. This combination also supported the largest lint yields, correlating increased lint yields with additional profit. Established on lower and upper profit, there is a 90% chance that if this combination is used in a M. incognita populated field, profit will fall between $692.42/ha and $875.58/ha. The input cost of this combination was $83.67/ha, making it one of the most expensive treatment combinations. A study conducted by Zimet et al. (2004) found that nematicide treatments in M. incognita fields with fewer input costs had reduced lint yields resulting in partial net returns.

There was a decrease in R. reniformis eggs per gram of root and an increase in seed cotton and lint yield with the combination of a nematicide and fertilizer at either PHS or PHS + FB. Greater profit per hectare was obtained in R. reniformis infested soil with combinations that included at least one nematicide in combination with an additional fertilizer at either PHS or PHS + FB. The three highest profiting treatments from field trials had an additional application of (NH4)2SO4 at PHS or PHS + FB. The same trend was seen with M. incognita ; eggs per gram of root were reduced and seed cotton and lint yield increased in combinations with a nematicide ST + an additional fertilizer combination at PHS or PHS + FB. Profit increased in combinations with a nematicide in combination with an additional application of fertilizer at PHS or PHS + FB. The three highest profiting treatments from field trials had an additional application of 28-0-0-5 at PHS or PHS + FB.

Our finding suggests that utilizing a nematicide with a fertilizer will increase yield and profit for growers with R. reniformis or M. incognita infested cotton fields. In R. reniformis field trials, 10 out of 10 fertilizer and nematicide combinations increased lint yields and 9 out of 10 combinations increased profits when compared to treatments with no nematicides. The three highest yielding combinations, a nematicide ST + (NH4)2SO4 at PHS and FB, a nematicide ST + (NH4)2SO4 + Vydate® C-LV at PHS and a nematicide ST + (NH4)2SO4 + Vydate® C-LV + Max-In® Sulfur at PHS also had the largest profits. Combinations with applications of (NH4)2SO4 were the most economical in R. reniformis infested fields. These field trials suggested that the application of a nematicide ST increased lint yield by 8% and a single application of Vydate® C-LV increased lint yield by 19%. The addition of a nematicide ST increased profit by $32/ha and an additional application of Vydate® C-LV at PHS increased profit by $137/ha when compared to an additional fertilizer alone. In M. incognita field trials, 10 out of 10 fertilizer nematicide combinations increased lint yields and profit when compared to treatments with no nematicides. The three highest yielding combinations were a nematicide ST + Vydate® C-LV + Max-In® Sulfur at PHS and FB, a nematicide ST + 28-0-0-5 at PHS and FB, and a nematicide ST + 28-0-0-5 + Vydate® C-LV at PHS also had the largest profits. Combinations with applications of 28-0-0-5 were the most economical in M. incognita infested fields. These trials suggested that the application of a nematicide ST increased lint yield by 20%, a single application of Vydate® C-LV increased lint yield by 11% and sequential Vydate® C-LV applications increased overall lint by 5%. The addition of a nematicide ST increased profit by $54/ha when compared to an additional fertilizer alone. The addition of a single application of Vydate® C-LV increased profit by $93/ ha and sequential applications of Vydate® C-LV at PHS and FB increased profit by $131/ha. In conclusion, our hypothesis that combining nematicides with fertilizers at PHS and FB plant growth stages can provide a management system for R. reniformis or M. incognita infested cotton fields with potential for economic gains.