Grain Sorghum Research in Western Nebraska

Figure 1. Grain sorghum variety trial at the Henry J. Stumpf International Wheat Center near Grant, Nebraska, summer 2019.

December 5, 2019

Strahinja Stepanović - Former Extension Educator

Cody Creech - Dryland Cropping Systems Specialist

Robert Klein - Emeritus Extension Professor

Jovan Radojičić – Agronomy Student at the University of Belgrade-Serbia

Ognjen Zivkovic – Agronomy Student at the University of Belgrade-Serbia

Grain sorghum is a warm-season grassy crop most known for its efficient water use and drought tolerance. It is primarily grown in the southern Great Plains, but recent genetic improvements have made it possible to grow it in cooler climates. Many Nebraska farmers have, therefore, implemented grain sorghum as a complementary part of their dryland crop rotation.

Chart showing standability of grain sorghum varieties in 15-inch vs 30-inch rows — Figure 2. Relationship between yield and standability of grain sorghum varieties evaluated during the 2019 growing season at Grant.

In semiarid western Nebraska, corn is the most prevalent crop in dryland crop rotations, taking up approximately 50% of the planted acres every year. However, research completed on grain sorghum in the central Great Plains region makes a compelling case for grain sorghum. It offers several advantages over corn under certain conditions:

Better yield under drier or limited irrigation environment (Klocke et al., 2014).
A 50% higher yield than corn in similar dryland crop rotations (Schlegel et al., 2019).
Lower cost of production inputs (e.g., price of certified seed).
Sorghum is a self-pollinated crop; thus, it is less affected by environmental stresses during pollination.

The disadvantages of grain sorghum compared to corn are mostly related to lower yield in higher rainfall environments, lower grain market price, and fewer marketing opportunities.

Variety Testing Initiated at Grant

To help western Nebraska farmers identify the best-adapted genetics for grain sorghum in the region, we initiated variety testing at Henry J. Stumpf International Wheat Center near Grant. In addition, we wanted to evaluate the effects of row spacing on sorghum varieties. We evaluated the performance of 24 grain sorghum varieties planted in 15- and 30-inch rows.

Trial summary

Site Description

Soil type: Kuma silt loam
Previous crop: Wheat (stripper header)
Tillage: No-till
Irrigation: None
Rainfall (May to October): 16 inches

Agronomic Practices

Planting date: May 17, 2019
Harvest date: Nov. 3, 2019
Row spacing: 15- and 30-inch rows
Seeding rate: 65,000 seeds/ac
Final population: ~45,000 plants/ac
Herbicide + fertilizer (April 27):
32 oz Buccaneer 5 + AMS
14 oz Verdict
16 oz atrazine 4L
29 gal of 32-0-0 (100 lbs N/ac)

Key Takeaways from the Study

Overall, grain sorghum yielded better in narrow rows. When averaged across all varieties, yield in 15-inch rows was 115 bu/ac, which was 20 bu/ac greater than in 30-inch rows (Table 1). K-State researchers reported a yield benefit of 4 bu/ac with narrow (15-inch) rows as compared to wide (30-inch) rows, especially when yields were above 70 bu/ac (Ciampitti, 2019).

High yields can be achieved in both 15- and 30-inch rows, but 15-inch rows had better yield stability. Although the best performing varieties in both 15- and 30-inch rows achieved a 132 bu/ac yield, the lowest ranked variety in 15- and 30-inch rows yielded 46 bu/ac (86 bu/ac) and 110 bu/ac (22 bu/ac) less, respectively (Table 2).

Variety performance ratings changed with row spacing. Among 24 varieties evaluated, 16 varieties yielded 10-77 bu/ac better in narrow rows, six varieties had similar yield (± 10 bu/ac) regardless of the row spacing, and only two varieties had at least a 10 bu/ac yield increase in wide rows. In our study, narrow rows yielded better 75% of the time. However, in a similar study, K-State researchers reported that 71% of all the observations yielded better with wider rows.

Each seed company had at least one top-performing variety, regardless of the row spacing. In western Nebraska where grain sorghum is not as widespread, increased competition can provide easier access to the good seed and agronomic services.

Avoid varieties with long maturity and lodging issues. Varieties evaluated in this study were early to medium in maturity and 51-67 days to mid-bloom (Table 1). Keep in mind that in our cooler environments, days to mid-bloom can be delayed by as much as 20 days when compared to what is reported by companies. The AS262 from Arrow Seed and two Hoegemeyer varieties (XP4720 and HPT 6064) seemed to be particularly late in their development, which affected their performance. Certain varieties had lodging issues when planted in 30-inch rows (Figure 2). For example, Dyna-Gro M57GB19 lodging was severe in 30-inch rows which caused it to be ranked 21^st among 24 varieties evaluated. In 15-inch rows, the same variety was ranked second best.

Conclusion

Grain sorghum has a great potential to be a part of dryland crop rotations in western Nebraska. Although this study was a good start for developing grain sorghum resources for Nebraska growers, we remind growers always to consider multi-year and multi-location data when making important agronomic decisions.

References

Schlegel, A.; Haag, L.; and Burnett, A. (2019) Large-Scale Dryland Cropping Systems. Kansas Agricultural Experiment Station Research Reports: Vol. 5: Iss. 7.

Klocke, N.L., R.S. Currie, I. Kisekka, L.R. Stone. 2014. Corn and grain sorghum response to limited irrigation, drought and hail. Applied Engineering in Agriculture, Vol 30 (6):915-924

Ignacio Ciampitti. Sorghum management considerations: Planting practices. K-State Research and Extension Agronomy eUpdate. Issue 747, May 17, 2019.

**Table 1. Yield (bu/ac), performance ranking, and variety characteristics of 24 grain sorghum varieties grown in 15- and 30-inch rows at Grant, Nebraska in 2019. (PDF version)**
Company	Variety	15-inch rows		30-inch rows		Yield Difference (15- vs 30- inch rows)	Variety Characteristics	Grain Color³	Plant Color⁴	Relative Maturity⁵	Days to Mid-bloom
		Yield (bu/ac)¹	Rank	Yield (bu/ac)	Rank Type/ Class²	(bu/ac)
Arrow Seed	AS212	114	13	125	2	-11	C	R	P	E	51
Arrow Seed	AS248FG	113	18	95	14	17	F	W	T	E/M	60
Arrow Seed	AS262	86	24	58	22	28	C	R	P	M	65
Dyna-Gro	M54GR24	123	7	97	12	26	C	B	P	E	54
Dyna-Gro	M57GB19	128	2	63	21	66	C	B	P	E	57
Dyna-Gro	M59GB57	118	9	132	1	-13	C	B	P	E	59
Dyna-Gro	M60GB31	117	10	84	19	33	C	B	P	M	60
Dyna-Gro	M60GB88	113	17	89	16	24	C	B	P	E/M	60
Dyna-Gro	M62GB77	109	19	94	15	15	C	B	P	M	62
Golden Acres	2620C	107	20	95	13	12	C	C	P	ME	58
Golden Acres	2730B	114	14	84	20	31	C	B	P	ME	59
Golden Acres	2950B	132	1	122	4	10	C	B	P	ME	58
Hoegemeyer	HPT 6020	124	5	124	3	0	C	R	—	E	62
Hoegemeyer	HPT 6064	99	23	22	24	77	C	B	—	ME	66
Hoegemeyer	XP4720	106	21	57	23	49	C	B	—	M	66
Pioneer	86P20	127	3	120	5	8	C	R	P	E	64
Pioneer	87P10	113	16	85	18	28	C	R	P	E	63
Pioneer	88P71	115	12	115	7	0	C	R	P	E	62
Sorghum Partners	SP 25C10	117	11	87	17	30	C	C	P	E	51
Sorghum Partners	SP 31A15	104	22	107	9	-3	C	B	P	E	57
Sorghum Partners	KS310	124	4	105	10	19	C	B	P	E	57
Sorghum Partners	SP 33S40	114	15	117	6	-3	F	C	T	ME	58
Sorghum Partners	SP 43M80	119	8	114	8	5	C	B	P	ME	60
Sorghum Partners	SP 68M57	123	6	100	11	23	C	B	P	ME	67
Average of all varieties		115		95		+20
Difference at 5% level (LSD)		17		15
Coefficient of variation (CV)		9		12
¹ Yield at 56 lbs/bu adjusted to 14% grain moisture ² C = commercial hybrid, F= Food hybrid ³ B=bronze, C=cream, R=red, Y=yellow, W=white, etc. ⁴ P=purple, T=Tan ⁵ E = early, E/M = early-medium, M = medium, M/L = medium-late, L = late

**Table 2. Ranking of grain sorghum varieties by their performance in 15- and 30-inch rows**
Rank	15-inch rows			30-inch rows
Rank	Company	Variety	Yield¹ (bu/ac)	Company	Variety	Yield¹ (bu/ac)
1	Golden Acres	2950B	132	Dyna-Gro	M59GB57	132
2	Dyna-Gro	M57GB19	128	Arrow Seed	AS212	125
3	Pioneer	86P20	127	Hoegemeyer	HPT 6020	124
4	Sorghum Partners	KS310	124	Golden Acres	2950B	122
5	Hoegemeyer	HPT 6020	124	Pioneer	86P20	120
6	Sorghum Partners	SP 68M57	123	Sorghum Partners	SP 33S40	117
7	Dyna-Gro	M54GR24	123	Pioneer	88P71	115
8	Sorghum Partners	SP 43M80	119	Sorghum Partners	SP 43M80	114
9	Dyna-Gro	M59GB57	118	Sorghum Partners	SP 31A15	107
10	Dyna-Gro	M60GB31	117	Sorghum Partners	KS310	105
11	Sorghum Partners	SP 25C10	117	Sorghum Partners	SP 68M57	100
12	Pioneer	88P71	115	Dyna-Gro	M54GR24	97
13	Arrow Seed	AS212	114	Golden Acres	2620C	95
14	Golden Acres	2730B	114	Arrow Seed	AS248FG	95
15	Sorghum Partners	SP 33S40	114	Dyna-Gro	M62GB77	94
16	Pioneer	87P10	113	Dyna-Gro	M60GB88	89
17	Dyna-Gro	M60GB88	113	Sorghum Partners	SP 25C10	87
18	Arrow Seed	AS248FG	113	Pioneer	87P10	85
19	Dyna-Gro	M62GB77	109	Dyna-Gro	M60GB31	84
20	Golden Acres	2620C	107	Golden Acres	2730B	84
21	Hoegemeyer	XP4720	106	Dyna-Gro	M57GB19	63
22	Sorghum Partners	SP 31A15	104	Arrow Seed	AS262	58
23	Hoegemeyer	HPT 6064	99	Hoegemeyer	XP4720	57
24	Arrow Seed	AS262	86	Hoegemeyer	HPT 6064	22
Difference at 5% level (LSD)			17			15
¹ Yield at 56 lbs/bu adjusted to 14% grain moisture