1. Assessment of allelopathic potential in Artemisia annua on maize, wheat and their some associated weed species By Hassanein, E.E; Abd El-Hamid, M.M. and M.S., Mekky Weed Res., Lab., Field Crop Res. Inst., ARC, Giza Egypt. Artemisia annua Arte misia plant

2. Objectives : T o study the allelopathic effect of wormwood extracts on germination, growth of maize and wheat as well as associated weed species.

3. A - Laboratory experiments: Two experiments were conducted as follow:-. Materials and Methods Experiment I (preliminary experiment): Included 14 concentrations (0, 3, 6, 9, 12, 15, 30, 45, 60, 75, 90, 120, 135 and 140 mg dry weight ml-1c water), replicated twice to determine sensitivity range of maize to the studied extracts. Experiment II: Included 8 concentrations (0, 3, 6, 9, 12, 15, 18 and 21 mg dry weight /ml) replicated three times to determine the required concentration to cause 50% inhibition of seed germination (I50).

4. B - Wire house experiments: - Three pot experiments were conducted to study the effect of wormwood extracts on maize, wheat and associated weed species in pots. Maize experiments: Two pot experiments were conducted to study the effect of wormwood extracts on maize and some weed species in pots as follow:

5. 1-Wormwood extract at 3 g/pot applied at 3 days after sowing (DAS). 2-Wormwood extract at 1.5 g /pot applied at 3 DAS. 3-Wormwood extract at 0.75 g/pot applied at 3 DAS. 4-Wormwood extract at 3 g/pot applied at 21 DAS. 5-Wormwood extract at 1.5 g/pot applied at 21 DAS. 6-Wormwood extract at 0.75 g/pot applied at 21 DAS 7- Check (control). The 1 St experiment included Seven treatments on pots in three replicates as follow:

6. The 2 nd experiment on maize included seven treatments in pots in replicated three times as follow: 1- Wormwood extract at 1.5 g/pot applied at 3 DAS. 2- Wormwood extract at 0.75 g/pot applied at 3 DAS. 3- Wormwood extract at 0.38 g/pot applied at 3 DAS. 4- Wormwood extract at 1.5 g/pot applied at 21 DAS. 5- Wormwood extract at 0.75 g/pot applied at 21 DAS. 6- Wormwood extract at 0.38 g/pot applied at 21 DAS. 7- Check (control).

7. Wheat experiment: Included five treatments in pots as follow: 1-Wormwood extract by natural white vinegar 2.5% acetic acid at 3 g/pot applied at 2-5 leaves of weed. 2-Wormwood extract by water at 3 g/pot applied at 2-5 leaves of weed. 3-Wormwood extract by water at 3 g plus 3.3 ml acetic 2.5%/pot applied at 2-4 leaves of weed. 4-Natural white vinegar 2.5% acetic acid at 50 ml/pot applied at 2-4 leaves of weed check (control). 5- Check (control).

8. The required concentration of extract for causing 50% inhibition of germination of maize was 4 mg/ml. Results and Discussion A- Laboratory experiments:

9. B - Wire house experiments 1 – Maize crop

10. 2- Post emergence application of wormwood extract at the rate of 0.75 g/pot achieved the best reduction of total weeds without any inhibitory effect on maize plant. Results of the 1 st pot experiment of maize 1- The post emergence application of wormwood extract at the rate of 3 g/pot achieved the highest reduction in number and fresh weight of weeds (100%), however, this dose reduced caused slight phytotoxicity to maize plants.

11. Table (1): Effect of aqueous acetic 5% extract of wormwood when applied either pre or post emergence on number of weed species under wire house condition (first exp. 4/3/2008). Number of total weeds (pl/pot) Number of canary grass (pl/pot) Number of broad leaved weeds pl./pot Concentration Total broad leaf weeds Other weeds Khardal barri Dentated dock Gossefoot 19.89.810.01.52.02.34.3 3 g/pot PRE 17.810.87.00.52.32.02.3 1.5 g/pot PRE 10.5456.00.33.30.02.5 0.75 g/pot PRE 0.0 3 g/pot POST 6.05.50.50.0 0.5 1.5 g/pot POST 7.83.54.30.51.52.30.0 0.75 g/pot POST 26.56.020.52.04.87.06.8 Check (control) 8.36.114.01.52.12.21.4 LSD

12. Table (2): Effect of aqueous acetic 5% extract of wormwood when applied either pre or post emergence on number and fresh weight of maize and weed species under wire house condition (first exp. 4/3/2008). Fresh weight of total weeds (g/pot) Fresh weight of canary grass (g/pot) Fresh weight of broad leaved weeds (g/pot) Concentration Total broad leaf weeds Other weeds Khardal barri Dentated dock Gossefoot 2.41.11.30.10.20.60.43 g/pot PRE 2.51.11.40.10.4 0.51.5 g/pot PRE 2.70.52.20.10.80.01.30.75 g/pot PRE 0.0 3 g/pot POST 0.30.20.10.0 0.11.5 g/pot POST 0.60.20.40.1 0.20.00.75 g/pot POST 7.00.66.40.31.12.92.1 Check (control) 1.7N.S0.90.10.60.50.6 LSD

13. Table (3): Effect of aqueous acetic 5% extract of wormwood when applied either pre or post emergence on maize under wire house condition (first exp. 4/3/2008). Maize Concentration Inhibition %Wight (g/pl)Inhibition % Number (pl/pots) 0.08.705.0 3 g/pot PRE 6.88.154.8 1.5 g/pot PRE 0.08.8104.5 0.75 g/pot PRE 44.84.8204.0 3 g/pot POST 11.57.754.8 1.5 g/pot POST 0.09.705.0 0.75 g/pot POST 0.08.705.0 Check (control) 1.40.6 LSD

14. Artemisia plant

15. pre-emergence Artemisi a plant 3 g/pot post-emergence

16. pre-emergence post-emergence Artemis ia plant 1.5 g/pot

17. 1- All studied concentrations of wormwood extract when applied at 3 days after sowing or at 1.5 and 0.75 g/pot when applied at 21 after sowing significantly reduced number and fresh weight of redroot pigweed, purslane and deccan grass. 2- Redroot pigweed and purslane as broad leaved weeds were more susceptible than deccan grass for wormwood extract. 3- Number and fresh weight of maize plant was not significantly affected by all wormwood extract concentration under study. Results of the second pot experiment of maize

18. Table (4): Effect of aqueous acetic 5% extract of wormwood when applied either pre or post emergence on number under wire house condition (second exp. 15/4/2008). Number of total weeds (pl/pot) Number of deccan grass (pl/pot) Number of total broad leaf weeds (pl/pot) Number of purslane (pl/pot) Number of redroot pigweed (pl/pot ) Concentration 4.71.03.70.73.01.5 g/pot PRE 10.43.07.40.76.70.75 g/pot PRE 14.05.38.71.77.00.38 g/pot PRE 12.76.06.74.02.71.5 g/pot POST 24.77.717.09.77.30.75 g/pot POST 41.116.724.49.714.70.38 g/pot POST 40.313.027.313.314.0Check (control) 11.25.38.43.56.4LSD

19. Table (5): Effect of aqueous acetic 5% extract of wormwood when applied either pre or post emergence on fresh weight of weed species under wire house condition (second exp. 15/4/2008). Weight of total weeds (g/pot) Weight of deccan grass (g/pot) Weight of total broad leaf weeds (g/pot) Weight of purslane (g/pot) Weight of redroot pigweed (g/pot) Concentration 21.02.618.41.217.21.5 g/pot PRE 39.01.237.80.837.00.75 g/pot PRE 57.214.342.92.340.60.38 g/pot PRE 28.614.514.14.99.21.5 g/pot POST 72.025.047.010.336.70.75 g/pot POST 75.512.063.518.345.20.38 g/pot POST 169.434.7134.725.3109.4Check (control) 43.511.538.59.739.3LSD

20. Table (6): Effect of aqueous acetic 5% extract of wormwood when applied either pre or post emergence on number and fresh weight of maize under wire house condition (second exp. 15/4/2008). Fresh weight of maize (g/pot) Number of maize plant / pot Concentration 168.74.8 1.5 g/pot PRE 158.35.0 0.75 g/pot PRE 159.05.0 0.38 g/pot PRE 167.34.6 1.5 g/pot POST 159.05.0 0.75 g/pot POST 161.75.0 0.38 g/pot POST 108.05.0 Check (control) 24.2N.SL.S.D

21. post-emergence pre-emergence 0.75 g/pot

22. B - Wire house experiments 2 – Wheat crop

23. Results of the third experiment of wheat 1- Application of wormwood extract by natural white vinegar at 3 g/pot from achieved the best reduction in number and fresh weight of canary grass when applied at 2-4 leaves. 2- Broad leaved weeds were more sensitive than grassy weeds.

24. 4-Wheat plants did not affected by different wormwood extracts and natural white vinegar 2.5% acetic acid (control) or water check. 3 - Number and fresh weight of most of broad leaved weeds as well as total annual weeds were significantly reduced by aqueous and natural white vinegar of wormwood extract at 3 g/pot when applied at 2-4 leaves.

25. Table (5) Effect of aqueous of wormwood and wormwood extracts by natural white vinegar 2.5% acetic acid extracts of wormwood as post emergence on number of weed species. Number of total weeds Number of grassy weeds (plants/pot) Number of broad leaved weeds (plants/pot) Concentration Total grassy weeds Canary grass Wild oat Total broad leaved Primpernel Khardal barri GossefootSowthistle 10.05.30.05.34.71.00.02.01.7 Wormwood by natural white vinegar (3 g/pot) 10.08.36.02.31.70.0 1.00.7 Aqueous wormwood extract (3 g/pot) 6.0 2.04.00.0 Aqueous wormwood extract (3 g/pot) + 3.3 ml acetic/pots 35.39.34.05.326.011.77.72.74.0 Natural white vinegar 43.38.03.05.035.314.313.33.04.7 Check (control) 3.32.52.3N.S2.92.33.6N.S.1.8 LSD

26. Fresh weight of total weeds Fresh weight of grassy weeds (g/pot) Fresh weight of broad leaved weeds (g/pots) Concentration Total grassy Canary grass Wild oat Total broad leaved Primpernel Khardal barri GossefootSowthistle 56.850.60.050.66.21.30.03.71.2 Wormwood by natural white vinegar (3 g/pot) 69.261.032.928.18.20.0 5.82.4 Aqueous wormwood extract (3 g/pot) 93.570.38.561.823.27.17.63.84.7 Aqueous wormwood extract (3 g/pot) + 3.3 ml acetic/pots 93.570.38.561.823.27.17.63.84.7 natural white vinegar 2.5% acetic acid 107.763.32.760.644.415.717.46.25.1 check (control) 30.9N.S8.4N.S8.43.84.76.82.6 LSD Table (5) Effect of aqueous of wormwood and wormwood extracts by natural white vinegar 2.5% acetic acid extracts of wormwood as post emergence on fresh weight of weed species.

27. Natural white vinegar Control

28. Aqueous wormwood mixed 3.3 ml natural white vinegar Extract of wormwood in solved natural white vinegar