Block · one region of the page, as the scanner read it. It may hold a whole story, part of one, several, or an advertisement; stitching blocks into articles is the next step. Text is supplied OCR.
Page 7 · column 5 of 7 · from the scan, no model involved
By TOMMY WILLIAMS
Rappahannock News Contributing Writer
Mowing has a profound effect on the individual plant as well as the ecology of the turfgrass community. It is generally a stress creating management practice and the total amount of stress that the practice creates on the turf is determined by the homeowner’s ability to make proper decisions about mowing height, frequency, time and patterns of mowing, type of mower and handling of clippings.
Selection of mowing height is perhaps the most important decision in mowing. Each species of turfgrass has a range of mowing heights under which it can exist over a broad range of climatic conditions with minimum stress. For example, a 1 1/2 inch to 2 1/2 inch mowing height is generally accepted as a moderately low stress creating mowing height for Kentucky bluegrass.
Lower mowing heights have been noted to: decrease the Leaf Area Index (unit of leaf area/unit of ground area), the amount of chlorophyll per plant, the weight of the individual grass plant, root and rhizome growth and synthesis, and storage of carbohydrates. Lowered mowing heights have also been noted to increase shoot density and plant succulence, weed invasion and predisposition to disease.
Therefore, it is generally accepted that choosing lower mowing heights leads to increased levels of stress. Research on weekly-mowed, greenhouse-grown Merion Kentucky bluegrass maintained at one and two inch mowing heights showed the slower mowing height produced five percent less clippings, 14 percent less roots, 22 percent less crown tissue* and 11 percent less rhizome tissue.
Other field studies also indicate lower mowing heights reduce root quantity. A four year study in Nebraska on 21 Kentucky bluegrass cultivars maintained at one and two inch mowing heights showed that the one inch mowing height produced 51 percent thatch than the two inch mowing height.
Mowing frequency can have an extreme effect upon root growth especially when more than 50 percent of the existing foliage is removed. Studies on previously uncut (>4 day old Kentucky bluegrass plants indicate that removal of 00 percent or more of the existing green tissue can load to a cessation of root growth within 2S days.
The more severe the defoliat ion, the faster the cessation of root growth. In these studies there was no root growth stoppage associated with green tissue defoliation levels of 40 percent or less even when clipped three times per week. Juska and Hanson examined greenhouse growth Merion Kentucky bluegrass at one inch and two inch mowing heights cut five times per week and weekly.
At the one inch mowing height they observed that the more frequent mowing reduced clippings 24 percent, roots 4t> percent, and rhizomes 45 percent. At the two inch
55.7%