INFLUENCE OF ALLELOCHEMICALS FROM JOHNSON GRASS EXTRACT ON THE SOWING QUALITY OF CARROT SEEDS IN ORGANIC AGRICULTURE SYSTEM

摘要

The carrots are cultivated only through direct sowing and their development from earliest stages yet passing in the interaction with weeds plants. The main aim of the present study was to establish the influence of allelochemicals, obtained from extract of the Johnson grass on the sowing behaviour of carrot seeds with target of organic growing. The whole plants in the stage of seed maturity were used for extraction. After thermal treatment at 40℃ the plant material was homogenised and 100 g of this mixture were diluted in 1 1. The following variants: control (only distilled water), 100% extract, and dilution with distilled water - 1:1, 1:3 and 1:7 were investigated. The carrot seeds were put for germination in the Petri dishes with filter paper, moistened with 5 ml of the extract. The germination energy, germination, fresh matter of sprout, rate and simultaneity of germination, length of hypocotyls and embryo roots were studied. The germination energy and germination decreased sharply in the variants with extract. The rate and simultaneity of germination were delayed. With increasing of the dilution those effects were smaller. The Johnson grass allelochemicals decreased significantly the carrot sprouts development which is very important in organic growing.