Before returning to our discussion regarding grasses and broadleaves, a drought update. The Drought Monitor Report, updated as of Tuesday, May 29th, shows easing of drought conditions. In the NW and SE corners of Kansas, the drought is gone and there is easing throughout much of the rest of the state. The rains of the last several days should reflect further easing next week; however, the well above normal temperatures towards the end of this past week will somewhat erase some of the benefits. At least much of the state now has the needed moisture to finish the wheat crop, benefit pastures and alfalfa greatly, and help the spring row crops establish strongly.
Now, back to the topic at hand. There are two more differences between grasses and broadleaf crops to mention.
• Pollination – Broadleaves typically rely on help in achieving pollination such as insects, bats and birds. That normally isn’t a huge problem until the pollinators aren’t around. If you pay the least bit of attention to agriculture news reports, it is virtually impossible to miss the declining European Honeybee populations being dealt with in the U.S. and other areas. While there are many types of bees, producers of fruits, vegetables, and other crops such as alfalfa rely on these bee for pollination. This is a weakness for these types of plants as having to rely on another organism to pollinate can lead to disaster if the organisms aren’t present. Many plant items we rely on from broadleaves are in danger if the pollinators become scarce or disappear. In California, the value of bee pollinated crops is in the hundreds of millions of dollars. While we didn’t go into differences here, grasses and broadleaves have markedly different flower structures. Grasses lack petals and sepals since they don’t need petals as they don’t need to attract pollinators. Instead grasses are self- or wind- pollinated. This has the advantage of not needing to rely on another organism for seed production and is considered more evolutionarily advanced.
• Vascular system – Both types of plants have a vascular system. Xylem to transport water and nutrients from the roots throughout the plant and phloem to transport the products of photosynthesis throughout the plant for growth and reproduction. Typically grasses such as corn and grain sorghum have vascular bundles scattered throughout the pith of the stem. Broadleaves have their vascular bundles on the outer edge of the stem. The easiest way to think of this is a deciduous tree such as an oak or maple. Most know you can determine the age of the tree by counting the rings. Each year is a ring with the youngest wood (xylem) on the outside. Just beneath the bark are the actively growing vascular bundles. This is why if you girdle a tree, cut into the trunk about an inch all the way around, you kill the tree as you have severed the vascular system.
There are many more differences between the two types of plants that matter but hopefully this provides a brief overview of basic differences and why they matter.
Dr. Victor L. Martin is the agriculture instructor/coordinator for Barton Community College. He can be reached at 620-792-9207, ext. 207.