POSSIBLE ALLELOPATHIC EFFECTS IN SUCCESIVE SPINACH (SPINACIA OLERACEA L.) AND RED BEET (BETA VULGARIS L. VAR. CONDITIVA ALEF) CULTURES

Abstract

The causes of mutual partial intolerance were studied in successive cultures of two species of Fam. Chenopodiaceae: spinach (Spinacia oleracea L.) and red beet (Beta vulgaris L.var. conditiva Alef.). In some cases comparisons with small radish (Raphanus sattivus L. convar. sativus) were done. In containers of limited volume of soil collected from previous crops were sown by successive crop, and the springing dynamic and plant weight gain during the first 20-30 days after emergence, were followed. There have been performed several tests cultivating the red beet after spinach, but also the reverse formula, spinach after red beet. In all tests there was registered a marked mutual intolerance, between spinach and red beet, manifested by spring delaying, the decreasing of the proportion of appeared plants, great loss of plants after emergence, clearly caused by the attack of specific ground diseases, slower weight gain after plant emergence, which may be caused by a shortage of nutrients in the soil, given by the presence of the previous plant. In the case of the tests, for which the phytopathological and poor nutrition causes were removed, the emerging delay effects and slower pace of increase in plant weight still remained, in reciprocal sequence cultivation of the spinach and red beet, which lead us to the conclusion of allelopathy phenomenon presence between the two species.