At the time of writing this report, 2018 Oklahoma wheat production is estimated to be 52.0 million bushels, which is 47% less than the 2017 production (Table 1) and 62% less than the 2016 production. The lower total grain production is the result of less wheat acres harvested across the state, primarily from abandonment due to drought or baled for hay, and the below-average yield. The 4.3 million planted acres was only down 4% compared to the previous year, but that was still 18% lower than the previous ten-year average. Number of harvested acres is estimated at 2.0 million, which is 31% less than in 2017 (Table 1), and the lowest number in the state since 1913. The statewide average yield is projected at 26 bu/ac. This is 8 bu/ac (24%) less than the 2017 state average and 3.6 bu/ac (12%) less than the previous ten-year average.
The 2017-2018 wheat growing season was a fight from start to finish for many producers across the state. The growing season got an early start due to an unusual August for Oklahoma. Temperatures were below normal, and rainfall totals were above normal for the month. This prompted producers interested in targeting fall forage to begin planting at the end of August. Planting continued to move rapidly through the Labor Day weekend, and most of the wheat during this time was sown into adequate soil moisture and emerged rapidly. Those producers who waited until after Labor Day to plant saw more unfavorable conditions as temperatures rose, and available soil moisture quickly dried up. Wheat planted during this time was “dusted-in” and finally received precipitation toward the end of the month into the beginning of October to get the seed to germinate. Wheat planting intended for grain-only was stalled during the average timeframe of early to mid-October due to these precipitation events. Once the ground dried enough, most producers were able to quickly make up time and get the crop planted, but some needed until November to finish.
After mid-October, the rain quit falling for the remainder of the calendar year. Crop conditions during the early part of the season were average but quickly deteriorated as the season progressed. This also led to a disappointing fall forage production and grazing season for most producers. Those who planted during late August to early September and were able to protect the crop from fall armyworm achieved good stands and had some available pasture later in the fall. However, those who waited until after Labor Day or later to plant were not as fortunate. The later planting and lack of precipitation resulted in low total fall forage production or no available pasture at all.
Drought conditions and average to below average temperatures persisted throughout January into February. Even for the producers who had available fall pasture, the drought conditions limited the overall number of days of grazing.
Some precipitation finally fell in parts of the state during late February into early March. For many fields, this was the first precipitation received since planting. Below average temperatures were observed coming out of winter, and plants broke winter dormancy later than normal. Below average temperatures persisted, resulting in slow overall growth and development during this time. The first hollow stem growth stage was reached for many varieties during the second to third week of March, which was 7 to 10 days later than normal. Unfortunately, the rain received during late February to early March was not quite enough to give any grazed wheat the boost it needed to recover well.
Overall growth and development continued at a slower than normal pace due to the second coldest April on record. Three separate and widespread freeze events also occurred during the first week of April, resulting in significant injury in some areas. Most wheat headed during mid- to late April because of the cooler temperatures, with this being 7 to 14 days behind normal. The prevailing thought was that this would translate into a later than normal harvest. However, the cold temperatures in April were followed by the warmest May on record. The warm temperatures and lack of rainfall advanced the crop quickly at this point, resulting in suboptimal conditions for the grain-fill period.
Most wheat was mature in southwestern Oklahoma by the end of May and by the beginning of June in the central to northern parts of the state. Producers for the most part were not delayed by rainfall events, and with the dry weather during June, much of the wheat was harvested timely and quickly.
Overall, harvest was almost complete in the state by late June. Yields throughout Oklahoma were variable depending on location but were below average overall. Part of this variability was due to overgrazing and whether an area caught or missed a rainfall event during early spring. Field averages of 15 to 30 bu/ac were the norm across much of the state, but higher averages, even into the 50 to 60 bu/ac range, were not uncommon in some areas that received timely rainfall. Test weights throughout harvest remained at or above 60 lb/bu for early-harvested fields and did not drop much below the upper 50’s towards the end of harvest. Protein content also remained at or above acceptable levels.
Different insects were a concern at times during the growing season, but few were widespread or season-long outside of the fall armyworm. Unless treated, the fall armyworm devastated those producers who planted in late August into early September. Many fields had to be replanted, and some producers commented that this was the worst that they had ever observed. Unfortunately, some reports indicated the fall armyworm was still causing damage into early November. The dry weather experienced across the state through the winter provided ideal conditions for winter grain mite and brown wheat mite to thrive on wheat plants coming out of winter dormancy, and there were some reports of fields warranting control. Aphids were not really on the radar screen of most producers until mid-March, but this pest was still not the limiting factor as observed in other years. Despite the low aphid numbers, Barley Yellow Dwarf (BYD) was evident in some fields as flag leaves and heads started to emerge. While there was quite a bit of leaf purpling and yellowing associated with BYD, there was not much stunting observed, with stunting resulting from “hot spots” of aphid pressure with early-season transmission of the virus. Wheat Streak Mosaic (WSM), transmitted by the wheat curl mite, was an issue again for producers in southwestern Oklahoma, but the overall impact of WSM was not as much as the 2016-2017 crop season. Reasons for this were related to later planting and emergence of some wheat; additionally, fields which may have had WSM were abandoned due to the drought or cut and baled for hay before symptoms could be observed.
Diseases were at low levels overall during the season, primarily due to the drought conditions. Parts of central to southcentral Oklahoma did experience low levels of powdery mildew, leaf rust, and stripe rust. In some cases, powdery mildew could be observed high in the canopy. For the remainder of the state, it was difficult to find foliar diseases, especially during stem elongation into the grain-fill period. One disease more prominent than in years past was Fusarium foot dry (dryland root rot). Signs and symptoms of this disease appeared suddenly during early May as hot temperatures returned and as the crop progressed through grain-fill. However, symptoms of this disease can appear similar to symptoms of premature death caused by freeze, drought, and other conditions. In parts of the northwest and panhandle regions, symptoms of dryland root rot may have been confused with symptoms caused by the drought and/or freeze, whereas in others (such as the wheat variety trial at Lahoma), damage caused by the April freeze events was expressed distinctly earlier. Because of the impact that leaf rust and stripe rust have had over the past several years, producers were ready to apply a foliar fungicide to susceptible varieties, but unfavorable conditions for disease development did not warrant an application in most cases. Variety trial results from Apache and Lahoma indicated that producers in these areas were justified in not spraying, as no evidence of a positive response to a fungicide application was found. However at Chickasha where low to medium levels of leaf and stripe rust and medium to high levels of powdery mildew were present, the two fungicide applications implemented at this location contributed to protecting the yield potential for a number of varieties compared to the non-treated plots of those same varieties.