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 Artemisia plant

Objectives : To study the allelopathic effect of

wormwood extracts on germination, growth of maize and wheat as well as

associated weed species.

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).

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:

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 DAS7- Check (control).

The 1St experiment included Seven treatments on pots in three

replicates as follow:

The 2nd 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).

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).

•The required concentration of extract for causing 50% inhibition of germination of maize was 4 mg/ml.

Results and Discussion

A- Laboratory experiments:

Inhibition % of grain maize

0

10

20

30

40

50

60

70

80

90

100

0 5 10 15 20 25Cocentration

I50

B - Wire house experiments

1 – Maize crop

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 1st 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.

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).

Concentration

Number of broad leaved weeds pl./potNumber of

canary grass

(pl/pot)

Number oftotal weeds

(pl/pot) GossefootDentated

dock

Khardal

barri Other weeds

Total broad

leaf weeds

3 g/pot PRE4.32.32.01.510.09.819.8

1.5 g/pot PRE2.32.02.30.57.010.817.8

0.75 g/pot PRE2.50.03.30.36.04510.5

3 g/pot POST0.00.00.00.00.00.00.0

1.5 g/pot POST0.50.00.00.00.55.56.0

0.75 g/pot POST0.02.31.50.54.33.57.8

Check (control)6.87.04.82.020.56.026.5

LSD1.42.22.11.54.06.118.3

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).

Concentration

Fresh weight of broad leaved weeds (g/pot)Fresh

weight of

canary grass

(g/pot)

Fresh weight of

total weeds

)g/pot(

GossefootDentated

dockKhardal

barriOther weeds

Total broad leaf

weeds

3 g/pot PRE0.40.60.20.11.3 1.1 2.4

1.5 g/pot PRE0.50.40.40.11.41.1 2.5

0.75 g/pot PRE1.30.00.80.12.20.5 2.7

3 g/pot POST0.00.00.00.00.00.00.0

1.5 g/pot POST0.10.00.00.00.10.2 0.3

0.75 g/pot POST0.00.20.10.10.40.20.6

Check (control)

2.12.91.10.36.40.67.0

LSD0.60.50.60.10.9N.S1.7

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).

ConcentrationMaize

Number (pl/pots)

Inhibition %Wight (g/pl)Inhibition %

3 g/pot PRE5.008.70.0

1.5 g/pot PRE4.858.16.8

0.75 g/pot PRE4.5108.80.0

3 g/pot POST4.0204.844.8

1.5 g/pot POST4.857.711.5

0.75 g/pot POST5.009.70.0

Check (control)5.008.70.0

LSD0.61.4

Artemisia plant

pre-emergence

Artemisia plant

3 g/pot

post-emergence

pre-emergence post-emergence

Artemisia plant

1.5 g/pot

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

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).

Concentration

Number of redroot pigweed (pl/pot)

Number of purslane (pl/pot)

Number of total broad leaf weeds

(pl/pot)

Number of deccan grass

(pl/pot)

Number of total weeds

(pl/pot)

1.5 g/pot PRE3.00.73.71.04.7

0.75 g/pot PRE6.70.77.43.010.4

0.38 g/pot PRE7.01.78.75.314.0

1.5 g/pot POST2.74.06.76.012.7

0.75 g/pot POST7.39.717.07.724.7

0.38 g/pot POST14.79.724.416.741.1

Check (control)14.013.3 27.313.0 40.3

LSD6.43.58.45.311.2

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).

Concentration

Weight of redroot pigweed (g/pot)

Weight of purslane (g/pot)

Weight of total

broad leaf weeds (g/pot)

Weight of deccan grass

(g/pot)

Weight of total weeds

(g/pot)

1.5 g/pot PRE17.21.218.42.621.0

0.75 g/pot PRE37.00.837.81.239.0

0.38 g/pot PRE40.62.342.914.357.2

1.5 g/pot POST9.24.914.114.528.6

0.75 g/pot POST36.710.347.025.072.0

0.38 g/pot POST45.218.363.512.075.5

Check (control)109.425.3134.734.7169.4

LSD39.39.738.511.543.5

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).

ConcentrationNumber of maize

plant / potFresh weight of maize

(g/pot)

1.5 g/pot PRE4.8168.7

0.75 g/pot PRE5.0158.3

0.38 g/pot PRE5.0159.0

1.5 g/pot POST4.6167.3

0.75 g/pot POST5.0159.0

0.38 g/pot POST5.0161.7

Check (control)5.0108.0

L.S.DN.S24.2

post-emergence pre-emergence

0.75 g/pot

B - Wire house experiments2 – Wheat crop

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.

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 .

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.

Concentration

Number of broad leaved weeds (plants/pot)Number of grassy weeds (plants/pot)Number

of total weeds SowthistleGossefoot

Khardal barri

PrimpernelTotal broad leaved

Wild oat

Canary grass

Total grassyweeds

Wormwood by natural white vinegar

(3 g/pot)1.72.00.01.04.75.30.05.310.0

Aqueous wormwood extract (3 g/pot)

0.71.00.00.01.72.36.08.310.0

Aqueous wormwood extract (3 g/pot) + 3.3

ml acetic/pots0.00.00.00.00.04.02.06.06.0

Natural white vinegar 4.02.77.711.726.05.34.09.335.3

Check (control)4.73.013.314.335.35.03.08.043.3

LSD1.8N.S.3.62.32.9N.S2.32.53.3

Concentration

Fresh weight of broad leaved weeds (g/pots)Fresh weight of grassy

weeds (g/pot)Fresh weight of total weeds SowthistleGossefoot

Khardal barri

PrimpernelTotal broad leaved

Wild oat

Canary grass

Total grassy

Wormwood by natural white vinegar

(3 g/pot)1.23.70.01.36.250.60.050.656.8

Aqueous wormwood extract

(3 g/pot)2.45.80.00.08.228.132.961.069.2

Aqueous wormwood extract (3 g/pot) + 3.3 ml acetic/pots

4.73.87.67.123.261.88.570.393.5

natural white vinegar 2.5% acetic acid 4.73.87.67.123.261.88.570.393.5

check (control)5.16.217.415.744.460.62.763.3107.7

LSD2.66.84.73.88.4N.S8.4N.S30.9

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.

Natural white vinegarControl

Aqueous wormwood mixed 3.3 ml natural white vinegar

Extract of wormwood in solved natural white vinegar