• Korean Journal of Weed Science
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• v.16 no.4
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• pp.309-316
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• 1996

In this study, germination characteristics and herbicidal response of green kyllinga(Kyllinga brevifolia var. leiolepsis H.) were investigated. The storage method desirable for a rapid dormancy release was to keep the seed under low temp. and wetting condition for one to two months, or high temp($40^{\circ}C$) and drying condition for three months. The dormancy of rhizome was hardly observed. The optimum temperature for germination of seed and rhizome was around $30^{\circ}C$ and 16-$20^{\circ}C$, repectively. The germination of dormancy-breaked seed was completely dependent on light. Shoot emergence ratio(%) was decreased with increase of planting depth ; for example, only 18% of rhizome segments planted in the depth of 4cm under soil surface emerged above soil surface. Flooding at earlier growth stage resulted in significant decrease in shoot emergence as well as in dry weight. The germinablity of rhizome was almost lost as a decreased in fresh weight reached to 50%. Usually, green kyllinga was sensitive to herbicides such as bentazone, bensulfuron and benfuresate etc. which were known to be effective in Cyperaceae weeds, indicating that green kyllinga can be used as a representative plant in the screening of herbicides for Cyperus weeds.

• Korean Journal of Weed Science
• /
• v.16 no.4
• /
• pp.301-308
• /
• 1996

In this study, a propagation characteristics of green kyllinga(Kyllinga brevifolia var. leiolepsis H.) was investigated. Two to three rhizomes(1st rhizome) arised from the basal part of main shoot at 4th leaf stage and were grown to extend on the soil surface. Then new shoots(lst tillers) emerged from every node of the 1st rhizome. Second rhizomes also arised from the basal part of lst tiller at the time of 4th leaf openning. With such a regularity, 5th rhizomes and about 688 shoots were produced from one plant during one year-cultivation without competition under the natural condition. The degree of vegetative growth and seed formation was 3 times and 2.5 times higher in rhizomeoriginated plant than in that from seed, respectively. The amount of seed formation and the 1000 seeds weight was highest in one planted on June 1 and Aug. 1, respectively. Short-day treatment of less than 14hr appeared to be necessary for the induction of flowering and it was effective as treated not during germination but since at least 2 leaf stage of green kyllinga. Each shoot individually responded to short-day. When plants were exposed to short-day (9hr, day / 15hr, night) treatment at the stage of 2-3 leaves, more than 7 cycles were required for flowering induction. Bolting in main shoot occurred after emergence of 4 leaves under the short-day condition. Exogenous $GA_3$ slightly accelerated the velocity of bolting only in short-day condition.