Phytotoxical effect of Lepidium draba L. extracts on the germination and growth of monocot (Zea mays L.) and dicot (Amaranthus retroflexus L.) seeds

A large number of plants impose inhibitory effects on the germination and growth of neighbouring or successional plants by releasing allelochemicals into the soil. This study investigated the phytotoxic effects of Tithonia rotundifolia (Miller) S.F.Blake on the chlorophyll and protein contents of Vigna unguiculata (L.) Walpers and Zea mays L.. This was with a view to determining the susceptibility of these crops to allelochemicals in the extracts prepared from T. rotundifolia. Seeds of the test plants were sown in pots filled with top humus soil. At two weeks, seedlings in each pot were thinned down to 10 seedlings per pot. Potted plants of the test crops were supplied with 400 ml of the appropriate water extracts while the control potted plants were supplied with 400 ml of water. Biochemical analyses were carried out according to standard methods. The data obtained were analysed by (ANOVA) to determine significant (P< 0.05) effects. The means were compared using Duncan Multiple Range Test. The chlorophyll a, chlorophyll b, total chlorophyll and protein contents in V. unguiculata and Z. mays and were significantly inhibited by the extract from T. rotundifolia. The inhibitory effects of these allelochemicals increased with concentration. The phytotoxic effect of T. rotundifolia was species dependent. It was concluded that the extract contains water-soluble allelochemicals which inhibited the biochemical parameters of the test crops. T. rotundifolia should be controlled where it grows in association with cultivated crops.

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Effect of reduced herbicide rates on weed control, environmental impact and profitability of corn

Canadian Journal of Plant Science ◽

10.4141/cjps08216 ◽

2009 ◽

Vol 89 (5) ◽

pp. 969-975

Author(s):

Nader Soltani ◽

Richard J Vyn ◽

Laura L Van Eerd ◽

Christy Shropshire ◽

Peter H Sikkema

Keyword(s):

Zea Mays ◽

Environmental Impact ◽

Zea Mays L ◽

Chenopodium Album ◽

Amaranthus Retroflexus ◽

Ambrosia Artemisiifolia ◽

Corn Yield ◽

Profit Margins ◽

Profitability Analysis ◽

Biomass Reduction

A study was conducted over a 3-yr period (2003, 2004, and 2005) to evaluate the effect of reduced herbicide rates - 20, 40, 60, 80, and 100% of the manufacturer’s recommended rate (MRR) - on weed biomass reduction, environmental impact (EI), yield, and profitability of corn (Zea mays L.) in Ontario. The herbicide rate required to provide 95% biomass reduction of velvetleaf (Abutilon theophrasti Medic.), redroot pigweed (Amaranthus retroflexus L.), common ragweed (Ambrosia artemisiifolia L.), common lambsquarters (Chenopodium album L.), and annual grasses was 92, 30, 41, 28, and 83% of the MRR for isoxaflutole plus atrazine, >200, 119, 23, 23, and 117% of the MRR for dimethenamid plus dicamba/atrazine, 141, 72, 46, 45, and >200% of the MRR for glufosinate plus atrazine, and 81, 29, 18, 24, and 88% of the MRR for nicosulfuron/rimsulfuron plus dicamba/diflufenzopyr, respectively. The herbicide rate required to provide 95% of weed-free corn yield was 61, 22, 130, and 11% of the MRR for isoxaflutole plus atrazine, dimethenamid plus dicamba/atrazine, glufosinate plus atrazine, and nicosulfuron/rimsulfuron plus dicamba/diflufenzopyr, respectively. Nicosulfuron/rimsulfuron plus dicamba/diflufenzopyr had the lowest EI. The results of profitability analysis suggested that the MRR rates do not tend to maximize profit margins. In most cases, there were no significant differences in profit margins for treatments with 40, 60, 80, and 100% of the MRR. Key words: Atrazine, dicamba, diflufenzopyr, dimethenamid, glufosinate, nicosulfuron, rimsulfuron, Zea mays L.

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Allelopathic effects of Androstachys johnsonii Prain on germination and growth of Zea mays L. and Vigna subterranea (L.) Verdc.

Technium Social Sciences Journal ◽

10.47577/tssj.v27i1.5225 ◽

2022 ◽

Vol 27 ◽

pp. 945-958

Author(s):

Mokgaetji Georginah Mokganya ◽

Hadzhi Maanda Ligavha-Mbelengwa

Keyword(s):

Zea Mays ◽

Rural Communities ◽

Zea Mays L ◽

Germination Rate ◽

Stem Bark ◽

Vigna Subterranea ◽

Allelopathic Effects ◽

Germination And Growth ◽

Androstachys Johnsonii Prain ◽

Traditional Crops

Allelopathic effects of the donor plants are mostly regarded as harmful to target plants such as traditional crops. Traditional crops play pivotal role as staple food for rural communities and hence ensuring food security. Study of the allelopathic effects of Androstachys johnsonii Prain on the germination and growth of Zea mays L. and Vigna subterranea (L.) Verdc was conducted. Different plant leachates concentrations of 0.675%, 1.25%, 2.5% and 5% were prepared through serial dilutions. Germination bioassays were arranged in a complete randomized setup of three replicates for each treatment for seven days. Germination rates were calculated, radicle and hypocotyl lengths were also measured. Germination rates of Z. mays L. and V. subterranea (L.) Verdc. ranged from 50 - 100% and 18 - 76%, respectively. Significant differences of P< 0.005 were noticed from the germination rates of V. subterranea (L.) Verdc subjected to high concentrations of different extracts used. Statistically there was no significant differences between germination rates of Z. mays L. treated with all concentrations of leaf leachates against germination rates of the seeds treated with distilled water. Outstandingly, the germination rate and early growth of Z. mays L. were promoted by less concentrated extracts of leaf, root, stem bark and soil which then suggest future use of allelochemicals from Androstachys johnsonii Prain for promotion of maize plant productions. Based on the beneficial attributes of allelochemicals from Androstachys johnsonii on the germination and growth of Z. mays L., planting of Androstachys johnsonii Prain in maize fields is highly recommended.

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