The west Texas region (South Plains and Rolling Plains) primarily produced high oleic varieties, with the majority of acreage planted in Flavor Runner 458. In the four twin row studies, using Flavor Runner 458, Sunoleic 97R, the new high oleic Texas A&M line TX97706 [Tamrun OL 01] and Tamrun 96, single row seeding rates were 4.4 seed/ft. and twin row rates were 8.8 seed/ft. (4.4 seed/drill), with rows seven inches apart. All varieties showed similar performance in single and twin row patterns.

The twin-row configuration showed an economic benefit in only one location. At the Monty Henson farm in Terry County, which produced the highest yield and had the greatest irrigation capacity, the twin-row yield surpassed the single row by 518 lbs/acre—an $89/acre increase after seed cost, based on the 2001 quota peanut loan schedule.

Variety trials were conducted concurrently, using TX97706, Tamrun 96, AT 108, Georgia Green and Georgia High O/L. The TX97706 performed exceptionally well, ranking first in four of the six tests in which it was used and showing great stability across all regional environments.

A Comanche County study evaluated the effect of seed size on stand and yield. Three commercial sizes of Tamrun 96 seeds (Wilco-590 seeds/lb., Wilco-740 seeds/lb. and Golden-850 seeds/lb.) were vacuum-planted at 6 seeds/ft., with the 590 and 740 count varieties delivering a significantly higher plant population than the 850 count. Yields throughout the studies were generally fair-to-good, and excellent in some areas.

The results indicated that the investment in time and materials to convert from single-row to twin-row configuration is not justified. It is also important to note that irrigation, always critical to peanut production, is even more so when increasing plant population with the twin-row configuration. Previous studies in Frio County, Texas showed that the twin-row pattern with ample irrigation produced economic yield responses.