The drought monitor report as of Tuesday, June 4 shows a decrease overall for drought conditions. Most of our area is still firmly entrenched in severe drought with part of our area in extreme drought. The eastern third of the state continues to improve. This doesn’t include any rainfall since Tuesday. The six to ten-day outlook (June 11 to 15) indicates a 33 to 50% chance of leaning to above normal temperatures and near normal precipitation. The eight to 14-day outlook (June 13 to 19) indicates a 50 to 60% chance of above normal temperatures and near normal precipitation. Good for wheat harvest but not summer row crops.
As we near wheat harvest, it’s useful to understand in general terms how plants grow, today grasses. Several comments are common regarding the wheat crop; “It’s shorter than normal”; “Harvest is earlier than normal”; “I remember when wheat harvest was always during July Fourth.” Understanding the how and why of grass growth explains why this is true.
• Factors controlling plant growth include available moisture, sunlight/day length, air and soil temperature, and plant nutrients. These factors influence all plant growth in some way and how they react to these factors is a function of the species and where it originated from and well as crop breeding. Today our focus is on winter wheat. Other grass crops like corn and grain sorghum react different to some of these factors. Remember the purpose of the plant isn’t to provide grain but to produce seed for the next generation of wheat plants.
• Winter wheat is an annual cool-season grass. It germinates in the fall, establishes itself prior to winter and if winter conditions are cold enough will go dormant. Since until spring, the growing point is below the soil surface, it can even lose all the above ground foliage and is just fine. It resumes growth in the spring while flowering, producing seed and maturing (dying) in summer.
• Naturally, adequate moisture and temperature play a significant role in growth. All plants respond to temperature and have an optimum range of temperatures. Warmer temperatures, up to a point increases growth and speeds up development. As a cool-season grass, wheat isn’t a fan of hot temperatures. As opposed to say corn, day length is a key in wheat development. It’s termed a long day-short night plant. In English, it won’t initiate flowering until day length increases past a certain amount. That coupled with vernalization, wheat won’t initiate flowering until exposed to a certain amount of cold, is designed for the plant not to start the process of flowering until winter is past. This is variety dependent.
• Now to answer the questions. Wheat is short as internode length, the length between joints is shorter due to growing conditions - lack of moisture. Wheat is shorter now period, as we have bred for a shorter crop. Harvest is earlier now for two reason – a lack of moisture combined with warm temperatures (heat can essentially kill the plant instead of letting it mature normally, and we have bred for shorter season varieties. Full season varieties can have greater yield potential under ideal conditions but we seldom have ideal here. So a big part of the reason under any conditions harvest is now earlier is breeding.
Dr. Victor L. Martin is the agriculture instructor/coordinator for Barton Community College. He can be reached at 620-792-9207, ext. 207, or martinv@bartonccc.edu.
