<abstract xmlns="http://www.w3.org/1999/xhtml">

Small plot cotton cultivar trials (12 trials) were conducted from 2016 to 2019 in fields infested with <italic>Meloidogyne incognita</italic>. Entries in these trials included commercial cultivars with partial and high resistance to <italic>M</italic>. <italic>incognita</italic>, as well as cultivars with no known resistance. Different resistant groups were created based on different cotton seed companies and their descriptions of the <italic>M</italic>. <italic>incognita</italic> resistant cultivars. Groups were none (susceptible); partial resistance found in Stoneville or Fibermax cultivars (PR-FM/ST); partial resistance found in PhytoGen cultivars (PR-PHY); resistance (unknown gene(s)) in Deltapine cultivars (NR-DP); and highly resistant cultivars homozygous for <italic>RK1</italic> and <italic>RK2</italic> resistant genes in PhytoGen cultivars (HR-PHY). The highest lint yields using a mixed model analysis were found in the PR-FM/ST (1,396 kg lint/ha), HR-PHY (1,327 kg lint/ha), and PR-PHY (1,314 kg lint/ha) groups. Yield for NR-DP (1,234 kg lint/ha) was not different (<italic>p</italic> > 0.05) than yield for susceptible cultivars (1,243 kg lint/ha). If the older resistant cultivars from Deltapine and PhytoGen (those with only Roundup Ready® herbicide technology) were removed from the analysis, then HR-PHY yields increased by 133 kg of lint/ha to 1,460 kg lint/ha and NR-DP yields remained approximately unchanged (1,227 kg lint/ha). Newer HR-PHY had much improved yield over the first HR-PHY cultivars. Newer HR-PHY averaged 17% higher yield than the susceptible group. LOG10 (<italic>M</italic>. <italic>incognita</italic> eggs/500 cm3 soil + 1) were highest for the susceptible cultivars (3.2), followed by PR-FM/ST (2.6), NR-DP (2.4), PR-PHY (2.1), and lowest with HR-PHY (1.4). The newer HR-PHY cultivars (those with ENLIST® herbicide technology) combine excellent yields (17% higher than susceptible cultivars) with high (96%) suppression of <italic>M</italic>. <italic>incognita</italic>.
</abstract>

Small plot cotton cultivar trials (12 trials) were conducted from 2016 to 2019 in fields infested with Meloidogyne incognita. Entries in these trials included commercial cultivars with partial and high resistance to M. incognita, as well as cultivars with no known resistance. Different resistant groups were created based on different cotton seed companies and their descriptions of the M. incognita resistant cultivars. Groups were none (susceptible); partial resistance found in Stoneville or Fibermax cultivars (PR-FM/ST); partial resistance found in PhytoGen cultivars (PR-PHY); resistance (unknown gene(s)) in Deltapine cultivars (NR-DP); and highly resistant cultivars homozygous for RK1 and RK2 resistant genes in PhytoGen cultivars (HR-PHY). The highest lint yields using a mixed model analysis were found in the PR-FM/ST (1,396 kg lint/ha), HR-PHY (1,327 kg lint/ha), and PR-PHY (1,314 kg lint/ha) groups. Yield for NR-DP (1,234 kg lint/ha) was not different (p > 0.05) than yield for susceptible cultivars (1,243 kg lint/ha). If the older resistant cultivars from Deltapine and PhytoGen (those with only Roundup Ready® herbicide technology) were removed from the analysis, then HR-PHY yields increased by 133 kg of lint/ha to 1,460 kg lint/ha and NR-DP yields remained approximately unchanged (1,227 kg lint/ha). Newer HR-PHY had much improved yield over the first HR-PHY cultivars. Newer HR-PHY averaged 17% higher yield than the susceptible group. LOG10 (M. incognita eggs/500 cm3 soil + 1) were highest for the susceptible cultivars (3.2), followed by PR-FM/ST (2.6), NR-DP (2.4), PR-PHY (2.1), and lowest with HR-PHY (1.4). The newer HR-PHY cultivars (those with ENLIST® herbicide technology) combine excellent yields (17% higher than susceptible cultivars) with high (96%) suppression of M. incognita.

The relationship between commercial cotton cultivars with varying <italic>Meloidogyne incognita</italic> resistance genes and yield

Journal of Nematology

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

The relationship between commercial cotton cultivars with varying  resistance genes and yield

running-head

Relationship between commercial cotton cultivars:

Small plot cotton cultivar trials (12 trials) were conducted from 2016 to 2019 in fields infested with Meloidogyne incognita. Entries in these trials included...

Cultivar	Mi category^b	Trials	Years
DP 1454NR B2RF	NR	2	2016
DP 1558NR B2RF	NR	9	2016 to 2017
DP 1747NR B2XF	NR	11	2016 to 2019
DP 1823NR B2XF	NR	3	2018 to 2019
FM 1621GL	PR	3	2018 to 2019
FM 1911GLT	PR	12	2016 to 2019
FM 2011GT	PR	8	2016 to 2018
PHY 250 W3FE	PR	1	2019
PHY 320 W3FE	PR	4	2018 to 2019
PHY 350 W3FE	PR	2	2018
PHY 400 W3FE	PR	4	2018 to 2019
PHY 417 WRF	HR	8	2016, 2017
PHY 430 W3FE	PR	1	2018
PHY 440 W3FE	PR	3	2018
PHY 480 W3FE	HR	6	2017 to 2019
PHY 500 W3FE	HR	2	2019
PHY 580 W3FE	HR	2	2019
ST 4946GLB2	PR	13	2016 to 2019

	Analysis for full data set				Omitting data for older cultivars⁴
R group²	Lint yield (kg/ha)	Eggs/500 cm³ soil	LE3	J2/200 cm³ soil	Lint yield (kg/ha)	Eggs/500 cm³ soil	LE	J2/200 cm³ soil
HR-PHY	1,327 ab²	154	1.5 d	27 b	1,460 a	340	1.4 d	27 b
PR-PHY	1,314 ab	2,071	2.1 c	59 b	1,330 ab	2,193	2.1 c	32 b
NR-DP	1,234 b	1,456	2.4 bc	76 b	1,227 b	1,880	2.4 bc	37 b
PR-FM/ST	1,396 a	3,310	2.7 b	146 b	1,396 a	3,283	2.6 b	73 b
None	1,243 b	7,871	3.3 a	336 a	1,244 b	7,867	3.2 a	168 a

The relationship between commercial cotton cultivars with varying Meloidogyne incognita resistance genes and yield

Published Online: Jul 29, 2020

Page range: 1 - 8

Received: Feb 17, 2020

DOI: https://doi.org/10.21307/jofnem-2020-064

Keywords
Cotton, Resistance, Southern root-knot nematode

© 2020 Terry A. Wheeler et al., published by Sciendo.

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Cultivars1 grouped into Meloidogyne incognita (Mi) resistance categories2 for analysis.

Least square means1 of nematode resistance groups for lint yield, Meloidogyne incognita eggs and second-stage juveniles (J2).

The relationship between commercial cotton cultivars with varying Meloidogyne incognita resistance genes and yield

Published Online: Jul 29, 2020

Page range: 1 - 8

Received: Feb 17, 2020

DOI: https://doi.org/10.21307/jofnem-2020-064

KeywordsCotton, Resistance, Southern root-knot nematode

© 2020 Terry A. Wheeler et al., published by Sciendo.

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Cultivars1 grouped into Meloidogyne incognita (Mi) resistance categories2 for analysis.

Least square means1 of nematode resistance groups for lint yield, Meloidogyne incognita eggs and second-stage juveniles (J2).

Keywords
Cotton, Resistance, Southern root-knot nematode