Effect of fertilizer and crop variety on the survival of Busseola fusca (Lepidoptera: Noctuidae) in cereals in Ethiopia

Abstract

Recent unusual high damage of finger millet Eleusine coracana (L.) Gaertn. and wheat Triticum spp. by Busseola fusca (Fuller) in Ethiopia prompted the initiation of this study that has involved comparing the host status of these crops with the main host, maize Zea mays. One improved variety and one local land race each of wheat, finger millet and maize were grown with and without fertilizer in a randomized complete block design to evaluate the effect of nitrogen and phosphorous fertilizers and varietal differences on the suitability of these host plants for the development of borer larvae. The results indicated that B. fusca larvae managed to survive up to the adult stage in the stems of finger millet and maize, while wheat failed to support larval development to pupation. The stems of fertilizer-treated crops hosted more larvae than those of untreated ones and these were significantly longer and heavier. Improved varieties tended to be more suitable for B. fusca development. Furthermore, irrespective of the crop species, improved varieties grown with fertilizer were more suitable for the development of B. fusca. An improved finger millet variety, KNE No. 1098, grown with fertilizer was as suitable as the improved maize variety A-511, grown without fertilizer. For wheat, however, immature mortality was 100% irrespective of variety and fertilizer level.

Hide and seek: management and landscape factors affecting maize stemborers Busseola fusca (Fuller) infestation levels in Ethiopia

“…Nitrogen input did not significantly influence stemborer infestation levels at the field (Table 2) and landscape levels (Table 4). This finding contrasts with studies that report that NPK fertilisation favours stemborer infestation (Debebe et al, 2008;Chabi-Olaye et al, 2008). However, the reported fertilisation rates which increased stemborer infestation were 60 to 120 kg ha -1 of nitrogen and were higher than the rates used in our area (yearly averages ranging between 54 and 70 kg ha -1 of nitrogen input); they were also below the recommended rates for this region, i.e 92 kg ha -1 of N (Tamene et al, 2017).…”

“…In addition, the applied fertilisation might not be completely taken up by the maize plants due to soil texture which affects the mineralisation rate (Kayser et al, 2011), phosphorus deficiency (Nziguheba, 2007) suboptimal timing of the application or rainfall conditions (rainfall shortage after urea application). While the effect of nitrogen fertilisation on stemborer infestation is generally reported as positive (Debebe et al, 2008;Chabi-Olaye et al, 2008) it is likely that there are many confounding factors, including rainfall, soil moisture, and other soil properties which determine the effect.…”

“…Plant density may affect the resource concentration for stemborers and therefore promote stemborer hosts finding success and oviposition preference (Kfir et al, 2002). Nitrogen fertilisation may enhance maize attractiveness and therefore enhance stemborer development rates, but it may also increase the tolerance of maize to stemborer attacks (Debebe et al, 2008). Hedgerows surrounding maize fields may provide resources and shelter for natural enemies of maize stemborers or, depending on the species composition of hedgerows, provide alternative host plants for maize stemborers.…”

Gene action conditioning resistance traits to spotted stem borer, Chilo partellus, in grain sorghum

“…In Kenya, much research has been accorded to C. partellus, consequently neglecting indigenous economically important stem borers such as the African stem borer. Research on management of B. fusca in sorghum has mainly focused on biological control and cultural control, predominantly intercropping, residue management, fertiliser use, and recently, genetic engineering (Chabi et al, 2005;Markus and Gurling, 2006;Amsalu et al, 2008).…”