Cabbage type rape

As a preliminary bioassay, some alkali metal salts of (9-aIkyl 1-(substituted phenoxyacetoxy)aUtylphosphonic acids IIA-IIE were tested for herbicidal activity on barnyard grass (Echinochloa crusgalli) and cabbage type rape (Brassica napus) by the Petri dish method. For further herbicidal activity evaluation, most of... 

Inhibitory potency (%) on the growth of plants in Petri dishes, 0 (no effect), 100 % (completely kill) Bm cabbage type rape Ech barnyard grass... 

As a preliminary bioassay, all the mono salts of 1-substituted phosphonic acid HF, IIG and IIH were tested at 100-10 mg/L for inhibitory effect against barnyard grass E. crusgalU) and cabbage type rape B. napus) using the Petri dish method. The results are listed in Tables 3.25, 3.26 and 3.27. 

As seen from Tables 4.19 and 4.20, the inhibitory potencies of all compounds against tested weeds decreased with the decrease of concentration of compounds. HIF-3, HIF-4, HIF-7, HIG-I, HIG-3, HIG-4, and HIG-7 displayed >90 % inhibitory activity against the root of barnyard grass and cabbage type rape at 100 and 10 mg/L. 

IIIH-9 (Yn=2,4-Cl2, R =pyrid-2-yl), and IIIH-IO (Yn=2,6-Cl2, R =pyrid-2-yl) showed >90 % inhibitory activity against the growth of root of cabbage type rape and barnyard grass. 

As a preliminary bioassay, the inhibitory activity of cyclic 1-hydrox-yalkylphosphonates IVA and IVB against barnyard grass (Echinochloa crusgalli) and cabbage type rape Brassica napus) were tested by using Petri dish methods. The inhibitory effect of IVA and IVB against the growth of roots and stems of tested plants were examined. The results are listed in Table 5.5. 

As seen from Table 5.5, IVA-8, IVA-10, and IVA-11 displayed the best inhibitory activity (>90 %) against the root of barnyard grass, while IVA-2, IVA-5 and IVA-8 displayed the best inhibitory activity (84-87 %) against the root of cabbage type rape at 10 mg/L. Other cyclic 1-hydroxyalkyIphosphonates showed weaker inhibitory activity at 10 mg/L. 

Only IVA-8 had 86 % inhibitory activity against the stem of barnyard grass, but weak inhibitory activity against the stem of cabbage type rape at 10 mg/L. All other cyclic 1-hydroxy alky Iphosphonates showed weaker inhibitory activity against the stem of barnyard grass and cabbage type rape at 10 mg/L. 

IC50 is effective dose that provides 50 % inhibition against the growth of plant (root or stem) Ech barnyard grass Brn cabbage type rape... 

As shown in Table 5.13, IVC-I6-23 displayed good inhibitory effect (>90 %) on the growth of roots of cabbage type rape and barnyard grass at 100 and 10 mg/L. They will be further examined for their pre-emergence herbicidal activity in the greenhouse. 

As seen from Table 5.18, most of cyclic phosphonates IVE displayed significant inhibitory effect (>90 %) against the growth of stem of dicotyledonous cabbage type rape, but showed much weaker or no inhibition against the growth of stem of monocotyledonous barnyard grass except IVE-7 with 80 % inhibitory activity at 100 mg/L. Based on the preliminary bioassays by Petri dish methods, the post-... 

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