Barrier crops and straw mulch as cultural management of Ethiopian pepper mottle virus in Ethiopia
Kidist Fekadu Wolde
Hawassa University, Wendo Genet College of Forestry and Natural Resources, Agroforestry, Ethiopia
Pepper mottling is an endemic and important disease of pepper in Ethiopia. It is caused by a non-persistently transmitted Ethiopian pepper mottle virus (EPMV) (Potyvirus). The disease is becoming an important constraint of pepper production in the central rift valley part of the country. Management techniques have not been yet evaluated for the virus or/and its aphid vectors. The study was conducted with the objective of identifying the potential of two different border crops and wheat straw mulch as cultural management practices. Field experiments were conducted at two localities; Ziway and Awassa. Aphids were trapped by using yellow water traps two times weekly, from August to November 2008. The incidences of EPMV infected plants were monitored once a week and data on yield and yield components were taken at harvest. Correlation was made between EPMV disease incidence with aphid build up, on one hand, and with the yields of pepper on the other hand. Glass house experiments were conducted on the border crops to verify the virus-sink hypothesis. The result revealed that maize border with and without mulch significantly (P=0.05) reduced aphid population and hence delayed the onset of EPMV disease incidence and decreased the rate of disease progress. In addition, it significantly increased marketable pod yield by reducing unmarketable ones. Sole mulch had the same effect, although, the result was not consistent between locations. Cabbage with and without mulch did not reduce the aphid population, thus the onset and rate of EPMV disease incidence. The result form glass house experiment revealed that both maize and cabbage could effectively sink EPMV. From the results of both experiments, it is concluded that maize which has both the sink and barrier working mechanism could be used a potential border crop in the management of EPMV. On the other hand, cabbage is found to be unsuitable to be used as border crop, as it may inhabit different aphid species vectoring EPMV. However, mulit-seasonal and –locational trials are still required to make reliable recommendation.
Keywords: Aphids, border crops, Capsicum spp, Plant virus, wheat straw
Contact Address: Kidist Fekadu Wolde, Hawassa University, Wendo Genet College of Forestry and Natural Resources, Agroforestry, Shashemene 128, 251 Shashemene, Ethiopia, e-mail: kidistfekadukfgmail.com