1. Sorghum Opportunities
Rick Kochenower
Dept. of Plant and Soil Sciences

2. Grain Sorghum Planting date Planting rate Fertility
May have largest impact on yield
Planting rate
Fertility

3. Planting Date Rule 1 OSU recommends to not plant in May
Utilizes rainfall from wettest period in Oklahoma

4. Grain Sorghum Water Requirement

5. Caddo County

6. Jackson County

7. Crop Water Use
L.R. Stone

8. Water Use Comparison Crop
Threshold Water Use (inches of water for first unit of grain)*
High-Yield, Maximum Water Use (inches)*
High-Yield W.U.E. (lb grain/ in. water, slope)*
Low-Yield, Dryland Water Use (inches)**
Low-Yield W.U.E.
(lb grain/ in. water, total)**
Corn
10.9 25
420
(7.5 bu)
13.9
186
(3.3 bu)
Sorghum
6.9 21
353
(6.3 bu)
14.3
249
(4.4 bu)
Average annual rainfall for western Kansas = inches
*Stone ** Aiken, Lamm, Gordon, Staggenborg 8

9. Planting Date
Rule 2 keep flowering from occurring during the July 15 to Aug 15 period
Keep flowering from occurring during generally the hottest and dries period in Oklahoma

10. Grain Yields Planting date Grain Yield bu/ac 2003† 2004 2005 Two-year
April 1
75.2
80.6
74.1
77.4
April 15
60.3
67.9
61.0
64.4
May 1
47.5
46.1
39.0
42.5 *
May 15
43.5 NA
40.8
40.8 *
L.S.D.
13.5
18.0
7.0
6.4
† Note: Medium Maturity only
* Bird damage Date 3 and 4: 56 and 55% respectively

11. 2007
Performance trials at Homestead and Cherokee averaged and bu/ac respectively. Another study planted in May at Lahoma averaged 65 bu/ac.
Performance trial at Altus averaged 89.9 bu/ac while another study planted in early May averaged 79.3 bu/ac

12. Seeding Rate
OSU recommends a harvest population of 35 – 45,000 plant/ac
Little higher or lower doesn’t hurt
Performance trials have had over 100 bu/ac yields with 28,000 plants at harvest
Germination for seed bag * the harvest population you want

13. Harvest Population 2004
Population
Yield
Heads/plant
20,000
49.9
1.94
30,000
70.5
1.68
40,000
74.6
1.22
50,000
78.9
1.08
60,000
82.0
0.84
70,000
88.4
0.91

14. Harvest Population Southwest 2007
Non tillering hybrid
Tillering hybrid
Yield
Head/plant
30,000
87.4
1.44
90.9
1.95
40,000
92.9
1.18
95.1
1.50
50,000
93.4
1.11
1.28
60,000
93.8
0.99
94.0

15. 5 plants in six inches equals 145,200 plants per acre or 9
5 plants in six inches equals 145,200 plants per acre or 9.7 lbs seed/ac

16. Grain Sorghum Fertility
Nitrogen
Yield goal * lbs N/bu of yield goal
Sorghum performance trials soil test + applied fertilizer = 135 lbs N/ac
2007 sorghum yields reduced by not enough N
Phosphorus
Soil test

18. Coming soon Select Max tolerant sorghum New broadleaf herbicide Huskie
Labeled on wheat now
Research going on in 2007

19. oaes.pss.okstate.edu/goodwell/

21. Questions