• English
    • français
  • English 
    • English
    • français
  • Login
View Item 
  •   Repository Home
  • Research Papers (RP)
  • RP-School of Pure and Applied Sciences
  • RP-Department of Zoological Sciences
  • View Item
  •   Repository Home
  • Research Papers (RP)
  • RP-School of Pure and Applied Sciences
  • RP-Department of Zoological Sciences
  • View Item
JavaScript is disabled for your browser. Some features of this site may not work without it.

Cereal yield losses caused by lepidopterous stemborers at different nitrogen fertilizer rates in Ethiopia

Thumbnail
View/Open
Full text article (253.1Kb)
Date
2006-05
Author
Kairu, E. W.
Wale, M.
Schulthess, F.
Omwega, C. O.
Metadata
Show full item record
Abstract
Field trials were carried out at three locations in the cool-wet western and one location in the semiarid eastern ecozones of the Amhara State of Ethiopia to determine the effects of nitrogen fertilizer on pest infestation and yield losses caused by lepidopterous stemborers in maize and sorghum. Three N fertilizer levels, i.e. 60, 120 and 180 kg/ha for maize, and 41, 64, and 87 kg/ha for sorghum, were compared with a zero N treatment. The dominant pest species were the noctuid Busseola fusca (Fuller) and the invasive crambid Chilo partellus (Swinhoe). Leaf N content was positively related to N fertilizer dosage. In general, pest density, parasitism, plant growth and borer damage variables increased with crop growth stage. On sorghum, in the cool-wet western Amhara, increasing levels of N fertilizer also tended to increase pest density, plant growth and damage variables. In the semiarid ecozone, parasitism by the exotic parasitoid Cotesia flavipes Cameron tended to increase with N level. In the cool-wet ecozone, sorghum yields increased by up to 74% because of fertilization; losses caused by stemborers decreased linearly with N dosage from 49% to 36%. In maize, because of low borer densities, there were no discernable trends for pest infestation and yield losses. In the cool-wet ecozone, sorghum yields were positively related to insecticide application and plant height, and negatively to damage variables such as tunnelling and peduncle damage. In semiarid eastern Amhara, the effects of fertilizer on pest, damage and yield were low on both crops because of the higher soil fertility. The results indicate that the profitability of nitrogen fertilizer as an integrated pest management tactic in the control of cereal stemborers depends, among others, on the severity of borer damage and the soil fertility status prevailing in an area. It is concluded that N fertilizer helps minimize the impact of borers on grain yields, especially on sorghum and in the cool-wet ecozone.
URI
http://ir-library.ku.ac.ke/handle/123456789/9755
Collections
  • RP-Department of Zoological Sciences [225]

Designed by Library ICT Team copyright © 2017 
Contact Us | Send Feedback

 

 

Browse

All of RepositoryCommunities & CollectionsBy Issue DateAuthorsTitlesSubjectsThis CollectionBy Issue DateAuthorsTitlesSubjects

My Account

LoginRegister

Designed by Library ICT Team copyright © 2017 
Contact Us | Send Feedback