Crop, Soil and Environmental Sciences

Introduction The term allelopathy was originated by Molisch (1937)

Allelopathic potential tissues: leaves, stems, flowers, fruits, seeds and roots. (Putnam, 1988)

Mechanism: volatilization, leaching, decomposition of residues, and root exudation (Chou, 1990)

Introduction

Sweet Sorghum- allelopathic crop species, producing phytotoxins (Alan, 2009)

Major constituent : sorgolene

Sorgolene is found in the root exudates of most sorghum species

very potent allelotoxin that disrupts mitochondrial functions and inhibits photosynthesis (Alan, 2009)

Objectives

The allelopathic effect of different rates of sweet sorghum residue in the germination of weeds.

Methodology Greenhouse setup : Altheimer laboratory, Fayetteville

20 flat trays , 20 seeds/ tray

Area of the tray: 26cm*26cm = 676cm2

5 species of weeds

Methodology cont..

Plant materials : dried, chopped

2 cm in length

Treatments: (per 676cm2)0t/ha (0 gm)2 t/ha (33.124 gm)4t/ha (66.44 gm) 6t/ha (100.04gm)

Major weeds Barnyardgrass

velvetleaf

pitted morningglory

large crabgrass

Palmer amaranth

Results: Overall experiment plot

PMG 0t/ha

2 plants germinated

PMG 4t/ha

8 plants germinated

PA 0t/ha

BYG 2t/ha

Results

Major weeds 0 t/ha 2 t/ha 4 t/ha 6 t/ha Total

germination

Palmer amaranth 3 2 2 2 9

barnyardgrass 0 1 0 0 1

pitted morningglory 2 5 8 2 17

large crabgrass 2 2 2 0 6

velvetleaf 2 2 1 3 8

Summary and conclusion

Dormancy testing wasn’t done prior to the experiment.

None of the seeds were treated with any chemicals

None of the plant showed more than 20% germination.

The allelopathy effect of sweet sorghum couldn’t be verified.