| Budget Amount *help |
¥1,700,000 (Direct Cost: ¥1,700,000)
Fiscal Year 1987: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1986: ¥1,200,000 (Direct Cost: ¥1,200,000)
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| Research Abstract |
To obtain the informations on the cultivations of upland crops, the present studies were set up to clear the interactions between crops and weeds. Eight crops and 6 weeds were used as materials. The results obtained are summarized a follows.
(1) Aqueous extracts from crops and weeds inhibited the growth in rice seedlings. The extent of inhibition was remarkably great in the extracts from wheat, oat white clover, Spergula arvensis, Hydrocotyle sibthorpioides, and Houttuynia cordata. The extracts from oat, soybean, lupine and alfalfa also retarded germinatio fo Brassica napus.
(2) The residues of crops and weeds burried in soils inhibited the growth of radish and the degree of inhibition was great in oat, barley, Galium aparine and Artemisia vulgaris. Root exudates from alfalfa reduced growth and dry weight of radish.
(3) Methanol extracts from soils cultivated oat and alfalfa retarded germination of radish. The extracts from oat soils inhibited the growth of hypocotyl in radish and the methanol extracts form alfalfa soils inhibited the elongation of rice seedlings. Agueous and methanol extracts form oat and alfalfa inhibited remarkably growth of rice seedlings. The results suggest that two crops, oat and alfalfa have actions of allelopathy against crops and weeds.
(4) Allelopathic substances of methanol extracts from oat, alfalfa, Spergula arvensis and Hydrocotyle sibthorpioides were examined by means of physico-chemical procedures.
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