Sorghum producers in West Central and Low Rolling Plains of Texas have many good sorghum hybrids to choose from. The range of planting dates, however, occurs from late April to mid July. Many producers may not readily understand the different sorghum maturity classes or when they should or shouldn't be planted (i.e., what is a 110-day sorghum, and how may it vary?). In addition, early season cold tolerance is an attribute, which may be important particularly for early season plantings when good soil moisture is available. Likewise, tillering and its control may strongly influence the success of sorghum cropping particularly as planting date affects tillering (cool temperatures favor tillering). Hybrids that tiller have the ability to compensate upward if production conditions are favorable relative to the established plant population, but tillering hybrids also erode the ability to manage targeted plant populations and timely harvest.

These are general guidelines and are not an endorsement of any one hybrid or company. Suggested last planting dates for each hybrid are intended to be conservative in order to protect the producer. In northern locations of the Rolling Plains, move toward the earlier portion of the range of last planting dates for a particular hybrid. Check with the seed company representative in your area for specifics.

Keep in mind that flowering can be harmed by hot weather even when moisture is adequate. Sorghum hybrid grain yield is impacted by the number of heads per root system, the number of seed per head and the seed size/weight. These yield variables are influenced by available soil moisture and nutrients. It is risky agronomically and economically to establish a high plant population if droughty conditions occur.

Suggested sorghum seeding rates are influenced by the available soil moisture which differs by soil texture. Generally, sandy to sandy loam soil can store about 1" of available soil water per foot; a silty loam to clay loam soil can store about 1.5" inches per foot; and a clayey soil can store about 2" per foot. Typically, it takes 6-8" inches of available moisture (rainfall or in the soil) to bring a sorghum crop to the point of grain production, and each additional 1" of water should produce 350-425 lbs. of grain.

Seeding rates are adjusted based on the production factors at the time of planting. High quality seed planted under favorable conditions can have germination above 90 percent, and stand establishment of 80 to 90 percent of the germinated seeds. If difficult germination or stand establishment is expected, seeding rates should only be increased slightly. If a timely rain results in the establishment of a high plant population then the growing season must remain favorable to set and fill the grain. Since July and August are historically the hottest and driest months in Texas then plant stress can be expected and seeding rates should be adjusted.

For most dryland sorghum production in West Central and Low Rolling Plains of Texas, when soil profile moisture is adequate (>4" of available soil moisture), a good target is 30,000-35,000 seeds per acre. If soil moisture is low (2-4"), a lower seeding rate that will result in 25,000-30,000 plants per acre is advised. For any condition with poor soil moisture, especially as plantings approach July 1, consider 20,000 seeds per acre. For limited irrigation (6-10") with low soil profile moisture conditions, target 40,000-45,000 seeds per acre, but if soil moisture is good, consider 50,000-55,000 seeds per acre. For full irrigation levels, target 80,000 seeds per acre on June 1, but by July consider 100,000-110,000 seeds per acre for non-tillering hybrids and 80,000-90,000 seeds per acre for tillering hybrids.

In general the last recommended planting date based on the sorghum's maturity class:
Counties	Medium Maturity	Early Maturity
Borden, Scurry, Jones, Fisher, Howard,Mitchell, Nolan, Taylor, Callahan, and Counties North of the line from Schleicher to McCulloch	June 30	July 15
These suggested dates consider the length of sorghum maturity vs. historical averages for cool fall weather, which can be expected ahead of frost. Although these sorghum maturity classes may be planted later and be successful in many years, these guidelines should help producers understand when risk increases relative to achieving grain yield potential. If you must consider a very late sorghum planting, choose among hybrids that have estimated ‘days to maturity' of less than 90 days. Check among seed dealers for suggestions.

Work with your local seed company representatives to determine the best adapted hybrid. Tillering varies by hybrid and is impacted by planting rate. If you are using a low planting rate and want a low plant population with only limited tillering then let your seed representative know. There are only a few hybrids that have limited tillering. Other considerations include drought tolerance, insect resistance, disease resistance, days to flowering, plant height, grain color, and more.