PAPER TITLE :EFFICACY OF SOME PLANT EXTRACTS AS POST HARVEST GRAIN PROTECTANTS AGAINST CALLOSOBRUCHUS MACULATUS (F.) AND SITOPHILUS ZEAMAIS MOTSCH.

FUTA JOURNAL OF RESEARCH IN SCIENCE | VOLUME 9 NUMBER 2 2013

Paper Details

  • Author(s) : *M.O. Ashamo, O.O. Odeyemi and J.O. Akinneye
  • Abstract:

A study was conducted to estimate the efficacy of extracts of Zanthoxylum zanthoxyloides, Aristolochia ringens,
Colocasia esculenta and Morinda lucida as post harvest protectants of maize and cowpea seeds against Sitophilus
zeamais Mots. and Callosobruchus maculatus (F.) respectively. The study was conducted in the laboratory at
ambient temperature of 28±2oC and relative humidity of 75±5%. The extracts of these plants were made using
ethanol as solvent and were prepared at concentrations of 1.0%, 1.5% and 2.0%. Untreated seeds and solvent treated
seeds served as controls. At 2.0% concentration, all the extracts achieved high rate of insects mortality as they all
achieved above 98% death of S. zeamais and C. maculatus within four days of exposure. The results obtained from
this work showed that only the extract of A. ringens was able to prevent the emergence of adult S. zeamais and C.
maculatus and therefore achieved 100% reduction at 1.0%, 1.5% and 2.0% concentrations. Also, only the extract of
A. ringens was able to prevent damage to treated seeds by the insects and therefore achieved 0%WPI at all levels of
concentration. The effect of A. ringens in terms of adult emergence, percentage reduction, percentage damage and
weevil perforation index (WPI) was significantly (p<0.05) different from other extracts except extract of Z.
zanthoxyloides which also prevented the adult emergence of the insects and damage of the treated seeds at 2.0%
concentration. However, extract of Z. zanthoxyloides was also very effective on the insects as it achieved 100%
mortality within one day of exposure at 2.0% and its effect was significantly (p<0.05) different from other extracts.
The effectiveness of these extracts as grain protectants could be rated as follow A. ringens> Z. zanthoxyloides> M.
lucida> C. esculenta. For effective protection and control of infestation by S. zeamais and C. maculatus in storage
of maize and cowpea respectively extracts of A. ringens and Z. zanthoxyloides could be used on these food
commodities.
Keywords: protectant, Zanthoxylum zanthoxyloides, Aristolochia ringens, Colocasia esculenta, Morinda lucida
adult emergence, seed damage