ASPECTS REGARDING PYRETHRUM PLANT BIOLOGY IN ITS SECOND YEAR OF VEGETATION
Abstract
Pyrethrum (Chrysanthemum cinerariaefolium) is a perennial plant from which natural insecticides, the pyrethrins, are derived. Pyrethrum seedlings were planted in 2010, at a row distance of 70 cm with 3 different plant densities: 40000 plants/ha, 50000 plants/ha, 60000 plants/ha. Biology aspects of the mentioned plants in their second year of vegetation at Jucu, 2011 show a vegetation onset al the beginning of March, bud formation in the middle of April and full flowering in the middle of June. The height of the bushes was comprised between 45.17 cm and 52.72 cm, and the diameter between 40.73 cm and 48.28 cm. Most of the shoots in this experiment had between 1 and 3 branches ending with a bud. Flowering lasted until the second decade of July, when seeds were already formed. A second flowering occurs, if flowers are harvested. Planting pyrethrum at a density of 50000 plants/ha, leads to the formation of the largest bushes (in diameter) and the highest number of buds per plant, exceeding the other two distances tried. Nevertheless, the 60000 plants/ha density induces the formation of a greater number of seed.The papers published in the journal are licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License, which permits unrestricted, non-commercial use, distribution and reproduction in any medium, provided the work is properly cited.
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