Influence of Heterodera glycines Virulence Phenotypes on the Performance of Nematode-Protectant Seed Treatments

Number of soybean cyst nematode (SCN) females per gram of root dry weight, 30 days after planting, for PI 88788 seed (variety P37A27X) treated with different seed treatments, by SCN phenotype_

Treatment	HG type 0			HG type 2.5.7			HG type 1.2.5.7
	Females per gram roota	SE	Group	Females per gram root	SE	Group	Females per gram root	SE	Group
Untreated	33.7	5.6	A	486.1	91.4	A	508.8	103.5	A
Base	34.3	5.6	A	440.0	83.2	A	487.9	101.0	A
Base + Aveo EZ	43.7	6.9	A	451.1	86.5	A	394.6	80.8	AB
Base + Bio ST	37.4	6.0	A	401.5	76.3	A	467.9	95.5	A
Base + Clariva PN	31.1	5.1	A	442.9	84.7	A	441.5	89.9	A
Base + ILEVO	12.3	2.2	B	243.0	46.6	B	274.5	57.1	B
Base + Saltro	39.7	6.2	A	400.9	75.1	A	454.7	92.3	A
Base + Trunemco	42.2	6.9	A	393.9	75.3	A	394.4	80.6	AB
Main effect	F-value = 6.6, p < .0001			F-value = 3.9, p = .0005			F-value = 4.8, p < .0001

Soybean cultivar P37A27X (PI 88788) and seed treatments used in greenhouse experiments conducted in 2020 and 2021, including active ingredients, application rates, and manufacturers_

Treatment	Active ingredient(s)	Rate	Company
Untreated	N/A	N/A	N/A
Base	metalaxyl, pyraclostrobin, fluxapyroxad, clothianidin	See footnotea	See footnoteb
Base + Aveo EZ	Bacillus amyloliquefaciens PTA-4838	2 ml/100,000 seeds	Valent U.S.A. (San Ramon, CA)
Base + Bio ST	heat-killed Burkholderia rinojensis + fermentation media	195 ml/100 kg	Albaugh, LLC (Ankeny, IA)
Base + Clariva PN	Pasteuria nishizawae	130 ml/100 kg	Syngenta (Greensboro, NC)
Base + ILEVO	fluopyram	0.15 mg a.i. / seed	BASF (Research Triangle Park, NC)
Base + Saltro	pydiflumetofen	0.075 mg a.i. / seed	Syngenta (Greensboro, NC)
Base + Trunemco	Cis-jasmone, Bacillus amyloliquefaciens	20.2 ml / 100 kg	Nufarm (Alsip, IL)

Number of soybean cyst nematode (SCN) females per root, 30 days after planting, for PI 88788 seed (variety P37A27X) treated with different seed treatments, by SCN phenotype_

Treatment	HG type 0			HG type 2.5.7			HG type 1.2.5.7
	Females per roota	SE	Group	Females per root	SE	Group	Females per root	SE	Group
Untreated	9.0	1.7	A	106.9	11.7	A	119.2	8.8	A
Base	9.5	1.8	A	103.4	11.5	A	101.1	8.2	A
Base + Aveo EZ	11.7	2.1	A	90.7	10.4	A	90.6	7.0	A
Base + Bio ST	10.1	1.9	A	88.0	9.9	A	107.1	8.1	A
Base + Clariva PN	8.7	1.7	A	96.5	11.0	A	99.5	7.4	A
Base + ILEVO	2.6	0.6	B	34.8	4.1	B	41.5	3.6	B
Base + Saltro	9.9	1.8	A	91.4	9.9	A	94.9	6.9	A
Base + Trunemco	10.9	2.0	A	97.5	11.2	A	94.2	7.1	A
Main effect	F-value = 6.5, p <.0001			F-value = 11.9, p <.0001			F-value = 14.7, p <.0001

SCN populations and virulence phenotypes (HG types)_

Soybean lines	HG Type 0	HG Type 2.5.7	HG Type 1.2.5.7
	Female Index (%)a
1. PI 548402 (Peking)	2.4	0.6	18.4
2. PI 88788	5.8	86.1	92.7
3. PI 90763	0.7	0.0	0.2
4. PI 209332	0.0	0.0	0.0
5. PI 209332	3.1	80.6	72.0
6. PI 89772	0.8	0.0	0.2
7. PI 548316 (Cloud)	9.5	76.0	74.0

Soybean root dry weight, 30 days after planting, across all SCN phenotypes for PI 88788 seed (variety P37A27X), treated with different seed treatments_

Treatment	Root dry weight (g)a	SE	Group
Untreated	0.24	0.03	A
Base	0.24	0.03	A
Base + Aveo EZ	0.24	0.03	A
Base + Bio ST	0.25	0.03	A
Base + Clariva PN	0.24	0.03	A
Base + ILEVO	0.17	0.03	B
Base + Saltro	0.23	0.03	A
Base + Trunemco	0.25	0.03	A
Main effect	F-value = 14.3, p < .0001