ABSTRACT
The research
project on comparative evaluation of some ethnobotanical dusts with actellic
dust for the control of cowpea weevil on stored cowpea seeds was conducted at
pathology laboratory Federal College of Agriculture Ishiagu, Ebonyi State in
2017. Completely Randomized Design was used. There were five treatments
replicated four times. The treatments were Azadiracta indica, Xylopia
aethiopica, Piper guneense, actellic dusts and control. The dusts were applied
10g per 1kg cowpea seeds. The criteria used for assessing the efficacy of these
products included mortality at 3 days, 6 days, 9 days, 12 days and 15 days
after treatment; number of surviving adults after 15 days of treatment and
number of larvae and pupae. The results shows there were significant
differences (p < 0.05) among the treatments on mean mortality and number of
surviving adults, larvae and pupae after 15 days of treatment. Result indicated
that both actellic dust and ethnobotanical dusts achieved high mortality while
T5 (control) recorded the least mortality. T5 (control) recorded the highest
mean surviving adults with mean number of 51.0 followed by T1(Xylopia
aethiopica) with mean number of surviving adults of 0.50 while T4 (actellic
dust) recorded no surviving adults. Results obtained also showed that, T5
(control) recorded the highest mean number of larvae with mean value of 9.00
and mean number of pupae 3.50. The result also indicated that all plant
extracts and actellic dust had adverse effects on the developmental stages of
cowpea beetle.
CHAPTER ONE
1.0
INTRODUCTION
1.1 Background of the Study
Cowpea (Vigna unguiculuta) is the second most
important food grain legume in tropical Africa belonging to the family of
Fabaceae. Cowpea is a supplementary stable food in the cities (Adejumo, and
Raji, 2007). In Africa cowpea is
especially boiled and eaten with other dishes such as rice, yam, plantain, and
bread and so on. it can also be milled (after brief soaking in water) and fried
in oil with spices to form cakes , or akara balls, a common breakfast menu
usually eaten with maize pap (Anonymous,2010).
Cowpea
storage may be conducted for the purpose of; maintaining regular supply
throughout the year, sale in times of scarcity at high prices to fetch more
money, preservation of seeds for planting at the next cropping seasons and it
also encourages price stabilization when government buys and releases them
periodically in times of scarcity to force prices down and prevent inflation
(Makanjuola, 2012). The various storage methods adopted by farmers depend on
the purpose of storage and the quantity of cowpea produced or procured for
storage (Ekwubiri, 2005).
Cowpea
beetle (Callosobruchus maculatus)
attack cowpea both in the field and storage (Singh et al., 2007). Attack usually starts with females laying eggs on
ripening cowpea pods in the field. (In Northern Nigeria, less than 5% of pods
are infested. Booker, 2003) during eclosion, the larvae burrow through the
chorion of the egg directly into the pod wall, and then into the seed, where
the larvae develop and pupate (Messina, 2013). Attack of cowpea beetle in the
field results to reduction in yield .it also causes reduction in quantity and
quality on stored cowpea seeds (Abunge, 2006).
Actellic
dust has been widely used in the control of insect pests of stored products
(Collins et al., 2012). It is a broad spectrum insecticide for use as a grain
admixture and for fly control in industrial and domestic buildings, refuse tips
and abattoirs. It may be added to grain for human or animal consumption to con
established infestations or prevent infestation (Orion, 2012). Actellic dust
contains 20g/kg of pirimiphos-methyl in the form of a dust as the active
ingredient.
1.2 Statement of the problem
Today
cowpea seeds are destroyed by pest (cowpea beetle, Callosbruchus maculatus) causing loss or reduction in quantity and
quality. According to Hanazato (2011), Chemical control of cowpea weevils are
not health or environmentally friendly. Sellers and producers use chemical
control agent such as actellic dust to store cowpea seeds, so that it will make
cowpea to be available, attractive, for high market value not minding the
health hazard it will cause.
Actellic
dust contains pirimiphos-methyl, the effect of which is that after cooking
grain stored with it, these chemicals impart objectionable odour and taste to
the meal and may be remotely toxic to human being. The untrained personnel
cannot handle it well and these have increased the health problems imposed by
the use of this chemical control method.
1.3 Objectives
of the study
The
objectives of this study are;
I. To compare some ethnobotanical dusts (Azadiracta indica seed powder, Piper guineense (uziza) seeds, Xylopia aethiopica (Uda) seeds dust)
with actellic dust for the control of cowpea beetle (Callosobruchus maculatus) on stored cowpea.
II. To proffer advice to sellers and producers
on possible alternative dusts for use in effective control of cowpea weevil in
place of actellic dust with a view to safeguarding public health.
1.4 Justification
of the study
Xylopia aethiopica, Piper guineense
and Azadiracta indica which are much
in abundance in the rain forest vegetation belt have some potentials in grain
preservation, which can be harnessed in the form of oil extracts and powders
for use in storage entomology as suggested by Bekele, (2010)., and Obeng-Ofori et al.,(2010), and Dike and Ajayi,
(2001).
The
research will help to increase the scope of cowpea production, storage and utilization,
to meet up with the ever increasing demand for cowpea and cowpea products.
This
can also help the ministry of agriculture to control the risk of using many
chemical substances in storage of cowpea seeds.
1.5 Scope
and Duration of the study
The
study is on comparative evaluation of some ethnobotanical dusts (Xylopia aethiopica, Piper guineense, Azadiracta indica) with actellic dustfor the
control of cowpea beetle on stored cowpea (Vigna
unguinculata).
The
study was carried out in pathology laboratory, Federal college of Agriculture
Ishiagu Ivo Local Government Area Ebonyi State in the year 2017. It lasted for
three weeks.