Grain sorghum, commonly known as milo, is cultivated primarily as a feed grain for livestock and is a significant global crop. Successful establishment begins with careful planning and execution during the planting phase. Achieving an optimal stand requires attention to specific environmental factors, including meticulous preparation of the planting site and precise management of the seed. Proper planting techniques set the foundation for the plant’s development and its ability to thrive.
Site and Soil Preparation
Preparation of the land before sowing ensures a favorable environment for seed germination and early root development. A preliminary soil test is the most reliable method for determining the existing nutrient profile and pH level of the field. Milo performs best when the soil pH is maintained within a range of 6.0 to 6.5, which facilitates the accessibility of most plant nutrients. Lime application may be required to adjust overly acidic soils into this preferred range.
The crop has substantial needs for macronutrients, with nitrogen and phosphorus being of particular concern for a strong start. A high-yielding milo crop can remove approximately 100 pounds of nitrogen and 14 pounds of phosphorus per acre. Nitrogen recommendations are often split, with a portion applied pre-plant or at planting, and the remainder side-dressed later in the season. Phosphate and potash applications should strictly follow soil test recommendations.
The physical condition of the seedbed must be fine, firm, and capable of providing good seed-to-soil contact. Regardless of whether conventional tillage or no-till systems are used, the area must be clean and free of existing weeds before the seed is sown. An effective burndown application is often employed to clear out winter and summer annual weeds that could otherwise compete with the emerging milo seedlings.
Optimal Planting Timing and Depth
The timing of planting milo is governed by specific environmental conditions, with soil temperature being the most important factor for uniform germination and emergence. To maximize the stand, the soil temperature at a two-inch depth should be consistently at or above 65°F (18°C). Planting at lower temperatures increases the risk of slow emergence and higher seedling mortality. The optimum planting window generally begins about 15 to 20 days after corn is planted in the same region, typically starting in mid-May.
The ideal planting depth for milo is between 1 and 2 inches, a range that balances the need for placement in moist soil with the seedling’s limited emergence vigor. Planting up to 2 inches deep may be necessary in lighter soils to reach adequate moisture. Planting too deep, beyond 2 inches, can delay emergence and reduce the final plant count.
Seeding rates are determined by the plant population goal, which varies based on expected rainfall and irrigation availability. For non-irrigated dryland environments, a common target is a final stand of around 60,000 pure live seeds per acre, while irrigated fields may target 80,000 seeds per acre or more. Seeding rates are adjusted upward to account for a typical field germination rate of 65% to 70%. Narrow rows of 15 inches or less can provide a yield benefit in high-yielding environments by allowing for faster canopy closure and better light interception.
Post-Planting Management
Once the seed is placed, attention shifts to securing the fragile stand against competition. Milo seedlings are particularly susceptible to weed pressure during the early establishment phase, making timely weed control necessary. An integrated strategy that begins with a pre-emergence herbicide application is recommended to control weeds before they emerge.
The goal is to maintain a weed-free environment until the milo plants reach the three- to five-leaf stage, when the growing point moves above the soil surface. If weeds emerge, early post-emergence herbicide treatments or mechanical cultivation are often necessary. Applying post-emergence herbicides when weeds are small is much more effective than waiting for larger growth. Early moisture management is also important; the young plants require sufficient moisture for the first few weeks of growth to ensure a robust stand.