13 research outputs found
Farmers control practices against the invasive red spider mite, Tetranychus evansi Baker & Pritchard in Benin
n 2008, the invasive tomato red spider mite Tetranychus evansi (Acari: Tetranychidae), a pest of sola-
naceous crops, was identi
fi
ed for the
fi
rst time as the cause of serious damage on tomato (
Solanum
lycopersicum
L.; Solanaceae) crops in Benin. Since then, frequent outbreaks have been observed on
Solanaceae and other leafy vegetables such as purple amaranth (
Amaranthus cruentus
L.; Amaranthaceae)
and bitter leaf (
Vernonia amygdalina
D.; Asteraceae) in all growing areas in southern Benin. The objective
of this study was to evaluate the intensity of damage by this invasive pest and the impact of farmers'
control practices on purple amaranth, African eggplant
(Solanum macrocarpon L.
; Solanaceae) and tomato
crops. A survey was carried out in January 2013 among 150 farmers in the three major growing areas in
southern Benin: S
em
e-Kpodji, Grand-Popo and Pahou.
Tetranychus evansi
was the only mite observed,
causing production losses estimated at 65% for African eggplant, 56% for tomato and 25% for purple
amaranth. Previously encountered species such as
Tetranychus urticae
Koch,
Tetranychus ludeni
Zacher
(Acari: Tetranychidae) and
Polyphagotarsonemus latus
Banks (Acari: Tarsonemidae) were not observed in
any of the 45 samples. To protect the infested crops, growers sprayed various synthetic pesticides at high
frequencies according to crop phenology 3, 6 and 12 times per month, respectively, on purple amaranth,
African eggplant and on tomato, on average. The most frequently used pesticides were pyrethroids and
organophosphate compounds. Farmers reported that these compounds were largely ineffective against
T. evansi
. The risks posed to human and environmental health, as well as existing alternatives to chemical
pesticide use, are discussedn 2008, the invasive tomato red spider mite Tetranychus evansi (Acari: Tetranychidae), a pest of sola-
naceous crops, was identi
fi
ed for the
fi
rst time as the cause of serious damage on tomato (
Solanum
lycopersicum
L.; Solanaceae) crops in Benin. Since then, frequent outbreaks have been observed on
Solanaceae and other leafy vegetables such as purple amaranth (
Amaranthus cruentus
L.; Amaranthaceae)
and bitter leaf (
Vernonia amygdalina
D.; Asteraceae) in all growing areas in southern Benin. The objective
of this study was to evaluate the intensity of damage by this invasive pest and the impact of farmers'
control practices on purple amaranth, African eggplant
(Solanum macrocarpon L.
; Solanaceae) and tomato
crops. A survey was carried out in January 2013 among 150 farmers in the three major growing areas in
southern Benin: S
em
e-Kpodji, Grand-Popo and Pahou.
Tetranychus evansi
was the only mite observed,
causing production losses estimated at 65% for African eggplant, 56% for tomato and 25% for purple
amaranth. Previously encountered species such as
Tetranychus urticae
Koch,
Tetranychus ludeni
Zacher
(Acari: Tetranychidae) and
Polyphagotarsonemus latus
Banks (Acari: Tarsonemidae) were not observed in
any of the 45 samples. To protect the infested crops, growers sprayed various synthetic pesticides at high
frequencies according to crop phenology 3, 6 and 12 times per month, respectively, on purple amaranth,
African eggplant and on tomato, on average. The most frequently used pesticides were pyrethroids and
organophosphate compounds. Farmers reported that these compounds were largely ineffective against
T. evansi
. The risks posed to human and environmental health, as well as existing alternatives to chemical
pesticide use, are discusse
Work system design with the ergonomic harmony framework for aging workforce
The general workforce is aging, especially in the Asian countries where most of the world's production operation is taking place, and it has indeed become one of the dominant issues in various sectors of industry all around the world. This paper develops a theoretical ergonomic evaluation and design model named 'Ergonomic Harmony Framework' for the aging workforce based on four existing approaches which are separately used to evaluate and solve the physiological, psychological, psychosocial and behavioral problems of human factors in a work system. A descriptive work system model and a mathematical framework specifically assessing this model are integrated for obtaining the harmony of the entire work system
Insecticidal activity of the medicinal plant, Alstonia boonei De Wild, against Sesamia calamistis Hampson*
The bioactivity of the aqueous extracts of the leaf and stem bark of the medicinal plant, Alstonia boonei De Wild (Apocyanaceae), against the pink stalk borer, Sesamia calamistis Hampson (Lepidoptera: Noctuidae) was studied in a laboratory bioassay. The extracts were incorporated into artificial diet at a rate of 0.0% (control), 1.0%, 2.5%, 5.0%, and 10.0% (w/w). Both extracts significantly (P<0.01) reduced larval survival and weight in a dose dependent manner. The concentrations that killed 50% of the larvae (LC50) for the stem bark extract were 2.8% and 2.1% at 10 and 20 DAI (days after introduction), respectively, while those for the leaves extract were 5.6% and 3.5%. The weights of the larvae also varied significantly (P<0.05) between the treatments in a dose dependent manner. We conclude that both leaf and stem bark extracts of A. boonei are toxic, used as growth inhibitors to S. calamistis larvae, and hold good promise for use as alternative crop protectants against S. calamistis