MISSISSIPPI STATE UNIVERSITY WHEAT AND OAT VARIETY TRIALS, 1994 Joe E. Askew, Ervin Baugh, Frankie Boykin, Carl Hovermale, David Ingram, Billy Johnson, Glen Jones, Jeff Main, Randy Saunders, Larry Trevathan, and Thomas R. Vaughan* Trials were conducted at 11 locations in Mississippi in 1993-94 (see map facing inside front cover). Public varieties (page 24) were selected by the Technical Advisory Committee for evaluation at each location. PROCEDURES Experimental design for each crop species at each location was a randomized complete block with four replications. Plots consisted of 7 rows spaced 7 inches apart and 20 feet long. Cultural and pest control practices used in each trial were as follows. Plots were limed and fertilized with P2O5 and K2O, according to soil test recommendations. Nitrogen was applied at 20 pounds per acre at planting and 80 and 45 pounds per acre in late February, for wheat and oats, respectively, except Verona, where 100 pounds were applied on the wheat test. Foliar fungicides were not applied, to insure that varieties were evaluated under conditions of maximum disease pressure. Herbicides, Hoelon and Harmony for wheat and Harmony alone for oats, were applied at each location, as needed, for broadleaf and grass weed control. Source of Seed...Seed of all private entries were supplied by participating companies. Seed of all public varieties were Breeder or Foundation Seed from the state that developed the variety. Planting Rate...All seeds were packaged for planting at the rate of 20 seeds per foot of row for both crops. Plots were planted with a cone, spinner-divider planter. Yield...A plot combine was used to harvest the total plot area after the plots were trimmed to a standard length. Harvested seed were converted to bushels/acre (60 pounds/bushel for wheat and 32 pounds/bushel for oats). Heading Date...The date when 50 percent of the heads were extended above the flag leaf. Plant Height...The height of plants was measured from the soil to the top of the spike or panicle. Lodging...Lodging was rated on a scale of 1 = almost all plants erect, 2 = all plants leaning slightly or only a few plants down, 3 = all plants leaning moderately or 25% to 50% of plants down, 4 = all plants leaning considerably, or 50% to 80% of plants down, and 5 = all plants down. Seed Test Weight...The test weight for each variety was determined from a composite sample from all replications. Disease Ratings...All varieties were rated for development of leaf rust and Septoria leaf and glume blotch, according to James' Manual of Assessment Keys for Plant Diseases (see Appendix). At growth stages 10.5 (spikes emerged) and 11.1 (milky ripe), 10 plants were selected at random from each plot at each location. The percentage of leaf area affected by each disease on the flag leaf was recorded. From these data, an assessment was made of the overall disease response of each variety. WEATHER SUMMARY BY LOCATION LOCATIONS 1 and 2--DELTA BRANCH: A hard-packing rain 3 days after planting sealed the sandy loam site, where a stand was not obtained. The clay site was in question but plots appeared okay 2 to 3 weeks later. The loam site was prepared to replant, but the weather did not permit a second attempt. LOCATION 3--NORTH MISSISSIPPI BRANCH: Timely rains after planting allowed quick emergence of all varieties. Air and soil temperatures were above normal during the winter months; therefore, no cold injury was observed among the plots. LOCATIONS 4 and 5--PONTOTOC RIDGE-FLATWOODS BRANCH: Heavy rains after emergence flooded some plots at the ridge location. Temperatures during heading were favorable for quick head emergence, and little variability was observed between varieties. Strong storms prior to harvest lodged some oat and wheat varieties and delayed harvest. No cold injury was noted. LOCATION 6--NORTHEAST MISSISSIPPI BRANCH: There was rain accumulation of 2.46 inches 3 days after planting for a 4-day period. Some surface erosion was observed and some seedlings washed away, resulting in a reduced plant population. A severe ice storm affected this location, resulting in moderate injury to the oats but no apparent impact on the wheat. The cool nights during grain-fill period enhanced yields. LOCATION 7--BLACK BELT BRANCH: Approximately 2.5 inches of rain fell 48 hours after planting, resulting initially in erratic stand emergence time. However, 3 weeks after planting, stands appeared to be sufficient for a test. Replication one appeared thinner at harvest, but was nearly equal to the other 3 replications when weighed. LOCATION 8--BROWN LOAM BRANCH: Over 1.33 inches of rain fell the same day of planting. Soil and air temperatures were favorable for germination, and emergence and good stands were obtained. Just over 5 inches of rain fell in December, but warm temperatures favored wheat and oat development. Spring weather conditions were optimum for wheat and oat development at Raymond. Plant diseases were not observed until well after heading and did not reach harmful levels. Harvest was accomplished on time, and yields of both wheat and oats were good. LOCATION 9--COASTAL PLAIN BRANCH: Severe stand reductions resulted from heavy rains (8.98 inches) over a 4-day period immediately following planting. Replanting occurred 12 days later, when it was realized that a stand would not be achieved in the compacted soil. A good stand was achieved following replanting. Following stand establishment, good growth occurred in the following weeks, but was not excessive due to the cool temperatures (13 þF, 14 F) in January. Growth and development progressed normally, because temperatures warmed up in February and rainfall was normal. LOCATION 10--SOUTH MISSISSIPPI BRANCH: Rainfall was almost 10 inches below the 30- year average for the wheat-growing season from November until May. Average monthly maximum-minimum temperatures were lower than the 30-year average for the wheat-growing season. However, there were only a few instances where the daily minimum temperature dropped below 32 þF. Disease pressure appeared to be light. A heavy rainstorm before harvest caused severe lodging. LOCATION 11--MISSISSIPPI STATE BRANCH: The weather after planting was near ideal for germination. An excellent stand was obtained, and no significant problems were noted throughout the growing season, thereby contributing to the high yields observed. TECHNICAL ADVISORY COMMITTEE Ned Edwards, Chairman Superintendent, South Mississippi Branch Wayne Houston Leader, Extension Agronomy Mississippi Cooperative Extension Service Ted Miller Extension Small Grain Specialist Delta Research and Extension Center Mitchell Roberts Superintendent Plant Science Research Center *Larry Trevathan Plant Pathologist Department of Entomology and Plant Pathology Mississippi State University *Coordinated disease ratings at all locations.