Techniques de criblage des variétés de sorgho vis-à-vis de la cécidomyie du sorgho, Stenodiplosis (Contarinia) sorghicola
Stenodiplosis sorghicola is one of the most damaging and widely distributed of all sorghum pests. In Africa, cultivation of midge resistant sorghum varieties is the best option for subsistence farmers. Techniques were set up in view of identifying resistance in sorghum cultivars, either under natural or artificial midge infestation. Farako-ba and Kouaré (Burkina Faso) and Longorola (Mali) are research stations that can be used at “hot-spots” for resistance screening under natural midge infestation. Midge pressure on test cultivars can be augmented by manipulating sowing dates, planting infestor rows, spreading midge-infested sorghum panicles containing diapausing larvae, increasing relative humidity by sprinkler irrigation, or controlling midge predators and parasitoids using selective insecticides. Artificial infestation allows an evaluation under high and uniform pest pressure, and under nochoice conditions. Twenty or 40 adult female midges are confined with sorghum panicles at anthesis, under wire-framed muslin cloth cages. Infestation is assessed by squeezing on a white sheet of paper, using an empty glass bottle, a random sample of 500 spikelets per cultivar. Orange stains are then counted, giving the percentage of midge-damaged florets. At crop maturity, midge damage is visually scored on a 1-9 scale, where 1 = < 10%, and 9 = > 80% midge-damaged spikelets.
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| Format: | conference_item biblioteca |
| Language: | fre |
| Published: |
CIRAD
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| Subjects: | H10 - Ravageurs des plantes, Sorghum, Contarinia sorghicola, variété, essai de variété, résistance aux organismes nuisibles, http://aims.fao.org/aos/agrovoc/c_7244, http://aims.fao.org/aos/agrovoc/c_30459, http://aims.fao.org/aos/agrovoc/c_8157, http://aims.fao.org/aos/agrovoc/c_26833, http://aims.fao.org/aos/agrovoc/c_5731, |
| Online Access: | http://agritrop.cirad.fr/478740/ http://agritrop.cirad.fr/478740/1/ID478740.pdf |
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