Sorghum Tips

Grain Sorghum Maturity – Impact on Yield?

This tip was provided by:

Ronnie Schnell, Cropping Systems – Statewide, College Station, ronschnell@tamu.edu

Statewide

Grain Sorghum Maturity – Impact on Yield?

Grain sorghum performance trials conducted by the Soil and Crop Science Department across Texas routinely measure plant characteristics, including days to bloom, plant height, panicle exertion, etc. These characteristics combined with yield data can be useful information when selecting hybrids for your farm.

The number of days from planting to mid-bloom is recorded for every plot each year in the statewide sorghum performance trials (about 1,600 plots per year). Companies designate maturity of hybrids that are entered in the trials and we do see variation in the days to flowering by region. The table below represents data from 12 sites over the last four years, or 48 site-years. Days to flowering tend to be longer in the Blacklands region of Texas and shorter in the High Plains of Texas (Table 1). Planting dates, which can affect temperature (heat unit accumulation) and photoperiod will influence days to flowering. However, maturity designations from companies do correlate with days to flowering ranging from an average of 59 days for early hybrids and 74 days for late hybrids.

Figure 1. Days to flower is defined as the days from planting to when 50% of plants are at mid-bloom.

Do hybrid maturities correlate with grain yield? I general yes, later maturities do produce greater yields on average. However, later maturities do not consistently produce greater yield across all production systems and environments. For irrigated sites, later maturing hybrids tend to produce greater yield in most environments. For sorghum performance trials (http://varietytesting.tamu.edu/grainsorghum/), this includes locations in the High Plains, South Texas Plains and Brazos Valley. For dryland locations in the Blacklands and Gulf Coast regions of Texas, medium to medium-late hybrids tend to produce greater yields on average. For dryland production in other regions of Texas, including the High Plains, earlier maturing hybrids would be preferred due to greater likelihood of soil moisture limitations.  In Texas High Plains dryland, though medium-long and long maturity hybrids sometimes produce higher yields in years with good rainfall, there is a risk of drought and these hybrids producing lower grain yield. (AgriLife recommendations for High Plains dryland generally do not recommend maturity longer than medium.)