What is in this article?:
- Aim a little higher for grain sorghum production
- Weed control improved
- Seeding rate, fertility, rotation and weed control all play a role in grain sorghum production.
- Planting too early could result in stressed seedlings.
- Planting too many seeds per acre is a mistake.
Calvin Trostle, Texas AgriLife Extension agronomist
“Aim a little higher with grain sorghum expectations,” recommends Texas AgriLife Extension agronomist Calvin Trostle. “Consider what you could do a bit better.”
Trostle, speaking at the Concho Valley Cotton Conference, in San Angelo, Texas, said seeding rate, fertility, rotation and weed control all play a role in grain sorghum production.
Planting on a bed also may limit grain sorghum success. “Grain sorghum roots do not like hot weather, and we want those brace roots in the soil.”
Planting too early could result in stressed seedlings. “We prefer that the soil temperature 10-day average be at 65 degrees F with 62 degrees the lower limit.”
He strongly urged farmers not to “over-populate the field. Planting too many seeds per acre is a mistake. A producer with proper seeding rate can make 1,200 pounds per acre (in stress conditions), and his neighbor makes hay.”
Concho Valley farmers should consider a 30,000 to 35,000 seed-per-acre planting rate with a final plant population ranging from 21,000 to 28,000 per acre. “That population should produce good results under a wide range of conditions.”
With irrigation and a good water resource, producers might bump the seeding rate up. “But if a farmer has doubts about bumping up his seeding rate, don’t! Less is more. Less seed means more yield.”
Trostle said producers may need to plug up some drills to get the proper seeding rate, and he also advises them to check uniformity with vacuum planters after the crop emerges to see if population is what they expected.
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Nitrogen fertility also makes a difference, Trostle said. “You don’t get something for nothing, at least not for long. Sorghum nitrogen fertility is important.”
The benchmark is two pounds of nitrogen for each 100 pounds of yield goal. That’s combined sources—applied and nitrogen available in the soil. He recommends a typical soil sample at zero to six inches and another deeper test for nitrogen. “Deep nitrogen can be credited 100 percent to the crop requirement,” he said.
At least 75 percent of the crop’s nitrogen demand should be available by heading. Trostle said growers should apply some pre-plant or at-planting and sidedress more 30 to 35 days after planting.