THE EFFECT OF HERBICIDES ON RESIDUAL EFFECTS OF
ATRAZINE UNDER CONSERVATION AGRICULTURE

THE EFFECT OF HERBICIDES ON RESIDUAL EFFECTS OF
ATRAZINE UNDER CONSERVATION AGRICULTURE

MUTSVANDIANI CHIKUTUMA

LOVEJOY TEMBO

WISDOM KURANGWA

An experiment was set up to evaluate the residual effect of atrazine in cowpea production under conservation
agriculture. The trial was superimposed on a previous herbicide trial of a maize crop in 2012/2013 season. The
experiment was laid out in a randomized complete block design with three replicates and four treatments as follows;
1. control (manual weeding), 2. Atrazine (3.6 litres/ha), 3. Atrazine (3.6 litres/ha) + glyphosate (2.5 litres/ha) and 4.
Atrazine (3.6 litres/ha) + glyphosate (2.5 litres/ha) + metolachlor (1 litre/ha). Herbicide treatment was carried out at
planting time and manual weeding at 10 cm weed height. Data collected include: germination percentage, weed
counts and weed biomass, cowpea biomass, pod length and cowpea yield. The herbicidal treatments showed a
significant effect (p<0.05) on pod length and cowpea yield. The control plot had the highest pod length of 17.03cm
and atrazine alone had the least of 15.77cm. A combination of three herbicides had the highest yield of 1.2t/ha and
atrazine alone had the lowest yield of 0.9t/ha. No significant (p>0.05) effects were recorded on percentage
germination, weed counts and weed biomass as well as on cowpea biomass. Tank mixing of two or more herbicides
is recommended when using atrazine to reduce residual effect and further research is recommended under different
soil types with different climatic conditions

Greener Journal of Agricultural Sciences

2015