The drought monitor report as of 8 a.m. Tuesday, Oct. 24, shows no real change again for our area this week. Things are still backwards as Western Kansas is still in the best condition regarding moisture for the entire state. The six to ten-day outlook (Oct. 31 to Nov. 4) indicates a 60 to 70% chance of below normal temperatures and a 33 to 50% chance of leaning to below normal for precipitation. The eight- to 14-day outlook (Nov. 2 to 8) indicates a 30 to 50% chance of leaning to above normal temperatures and normal for precipitation. The temperatures are leaning towards slower wheat development but the recent rains some areas received, which was pretty variable around here, will help with germination and root establishment. We are now entering the time of year when normal precipitation isn’t much.
Today, have you ever thought about plants and how they respond to the environment? How do they avoid blooming too early or making sure they flower and produce seed before winter? There are a variety of plants besides flowering plants but let’s focus on flowering plants. Even among flowering plants, for example: annuals, biennials, and perennials; monocots (grasses) and dicots (broadleaves); cool and warm season plants; finally, their place of origin regarding climate (temperature, moisture, and daylength). With that in mind, what are some of the common responses?
• If you are a plant species where day length varies a fair amount, more than 23.5 degrees north or south of the equator, you key flowering to daylength. If you are a summer annual and need to beat freezing temperatures, flowering is keyed to increasing uninterrupted night length. Why? Days become shorter long before temperatures become colder so to have adequate time to produce viable seeds you pay attention to daylength. The amount varies by species and hybrid/variety. If you a plant like winter wheat, you wait until day length increases. You are a short-night plant to prevent the onset of the flowering process until you have the best chance of avoiding freezing temperatures.
• If you come from an area closer to the equator, say corn or sorghum, your growth stage and flowering are keyed most closely to the accumulation of heat.
• If you come from an area close to the equator like alfalfa, you really don’t care about daylength as it doesn’t vary much at all.
• Another adaptation for plants like wheat is no matter how good the fall growing season is, how much the plant grows, flowering imitation can’t occur until the plant has accumulated a certain amount of cold.
• Other summer annuals, like many weed species won’t germinate until the seed has accumulated so much cold to prevent germinating in the fall.
• Some seeds, summer annuals especially, won’t germinate until a minimum soil temperature is reached.
• Finally grasses protect themselves by keeping the growing point below the soil surface for an extended period of time after emergence.
There are many other examples but you get the idea. Plants are uniquely adapted to their environment. We can manipulate it somewhat but there are limits.
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.
