ABSTRACT
A survey was carried out in three locations
(American quarters farm, National Root Crops and Research Institutes farm,
Michael Okpara University of Agriculture, Umudike farm) to access the incidence
and severity of bacterial leaf spot on three yam species (Dioscorea alata,
Dioscorea rotundata and Dioscorea dumentorum) in Umudike. Also a field
experiment and screen house trials were conducted at National Root Crops Research
Institutes (NRCRI), Umudike, southeastern Nigeria to assess bacterial leaf spot
disease ofthese three different yam species (Z>. alata, D. rotundata, D.
dumentorum). Bacterial leafspot disease of yam was surveyed in the field during
the 2016 cropping season. Results from the survey were based on varietal
performance. D. alata (1166) variety recorded (4.58,5.67, 7.33, 8.08, 9.75 and
37.50%, 41.67%, 50.00%, 54.17%, 62.50%) for disease severity and incidence
respectively, D. rotundata (Nwa) variety recorded (1.50, 2.75, 2.75, 3.58, 8.83
and 16.67%, 33.33%, 54.17%,66.67%,75.00%) for disease severity and incidence
respectively and D. dumentorum (Ekpe) variety recorded (1.58, 2.58, 3.17, 4.58,
9.00 and 20.83%, 37.50%, 29.10%, 79.17%, 87.50%) for disease severity and
incidence respectively. These three varieties (1166 for D. alata, Nwa for D.
rotundata, and Ekpe for D. dumentorum) were all observed to be more susceptible
than other varieties of the same species and the disease symptoms were more
with increase in rainfall. Infected leaves were taken to the plant pathology
laboratory for isolation and identification and pure culture obtained used for
pathogenicity in the screen house. Both field and screen house trials conducted
showed the potential of each extracts (Azadirachta indica, Eucalyptus
officinalis, Cymbopogon citratus, Ocimum gratissimum) in controlling bacterial
leafspot. Results obtained showed that all the plant extracts assessed reduced
disease incidence and severity when compared with control (sterile water). A.
indica recorded the best performance in growth and yield attributes (5.47kg)
closely followed by C. citratus (4.34kg). Therefore the study shows that plant
extracts could offer a safe alternative in management ofleafspot disease in
Umudike
EZEKIEL, E (2023). Studies On Bacterial Leaf Spot Disease Of Yam (Dioscorea Spp.) Induced By (Xanthomonas Campestris) In Umudike, South Eastern Nigeria:- Umoh, Ezekiel E.. Repository.mouau.edu.ng: Retrieved Nov 05, 2024, from https://repository.mouau.edu.ng/work/view/studies-on-bacterial-leaf-spot-disease-of-yam-dioscorea-spp-induced-by-xanthomonas-campestris-in-umudike-south-eastern-nigeria-umoh-ezekiel-e-7-2
EFFIONG, EZEKIEL. "Studies On Bacterial Leaf Spot Disease Of Yam (Dioscorea Spp.) Induced By (Xanthomonas Campestris) In Umudike, South Eastern Nigeria:- Umoh, Ezekiel E." Repository.mouau.edu.ng. Repository.mouau.edu.ng, 19 Dec. 2023, https://repository.mouau.edu.ng/work/view/studies-on-bacterial-leaf-spot-disease-of-yam-dioscorea-spp-induced-by-xanthomonas-campestris-in-umudike-south-eastern-nigeria-umoh-ezekiel-e-7-2. Accessed 05 Nov. 2024.
EFFIONG, EZEKIEL. "Studies On Bacterial Leaf Spot Disease Of Yam (Dioscorea Spp.) Induced By (Xanthomonas Campestris) In Umudike, South Eastern Nigeria:- Umoh, Ezekiel E.". Repository.mouau.edu.ng, Repository.mouau.edu.ng, 19 Dec. 2023. Web. 05 Nov. 2024. < https://repository.mouau.edu.ng/work/view/studies-on-bacterial-leaf-spot-disease-of-yam-dioscorea-spp-induced-by-xanthomonas-campestris-in-umudike-south-eastern-nigeria-umoh-ezekiel-e-7-2 >.
EFFIONG, EZEKIEL. "Studies On Bacterial Leaf Spot Disease Of Yam (Dioscorea Spp.) Induced By (Xanthomonas Campestris) In Umudike, South Eastern Nigeria:- Umoh, Ezekiel E." Repository.mouau.edu.ng (2023). Accessed 05 Nov. 2024. https://repository.mouau.edu.ng/work/view/studies-on-bacterial-leaf-spot-disease-of-yam-dioscorea-spp-induced-by-xanthomonas-campestris-in-umudike-south-eastern-nigeria-umoh-ezekiel-e-7-2