This study demonstrated that nematodes are present on most cultivated maize varieties in farmers’ fields in Uganda. Pratylenchus zeae was particularly prominent and was responsible for most of the damage. However, very few farmers are aware that nematodes are a serious maize production constraint. Since most varieties cultivated by farmers in Iganga and Masaka districts of Uganda were nematode-susceptible, the best management approach would be breeding cultivars with nematode resistance. The breeding aspect would be tackled by either sourcing exotic resistant germplasm for introgression into locally adapted germplasm or using a population improvement approach on selected cultivars.
Farmer-participatory approaches at the beginning of a breeding project would enable breeders improve the selection procedure by taking into account farmers' preferred traits at an early stage.
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Appendix 2.1: Site description and location of IITA
The International Institute of Tropical Agriculture (IITA) farm is loca
Busukuma subcounty, Wakiso district. The area is sometimes referred to as IITA
a name it acquired from the original owner of the farm. Namulonge farm is in the mid elevation humid forest zone, 28 km north of Kampala (32
an average rainfall of approximately 1300 mm, an average annual temperature of 22 soils are dark reddish-brown sandy loam orthic ferralsols
1992).
Location of IITA-Namulonge farm
Figures are modifications of maps obtained from
http://maps.google.co.ug/maps?hl=en&tab=wl&q=namulonge Appendices
1: Site description and location of IITA-Namulonge farm
The International Institute of Tropical Agriculture (IITA) farm is located at Namulonge village, Busukuma subcounty, Wakiso district. The area is sometimes referred to as IITA
a name it acquired from the original owner of the farm. Namulonge farm is in the mid 28 km north of Kampala (32°34’E, 0°32’N) at 1200 m a.s.l
an average rainfall of approximately 1300 mm, an average annual temperature of 22
n sandy loam orthic ferralsols with a pH range of 5.5 to 6.2 (IITA,
onge farm
Figures are modifications of maps obtained from http://en.wikipedia.org/wiki/Namulonge /maps?hl=en&tab=wl&q=namulonge (B)
41 ted at Namulonge village, Busukuma subcounty, Wakiso district. The area is sometimes referred to as IITA – Sendusu, a name it acquired from the original owner of the farm. Namulonge farm is in the mid at 1200 m a.s.l. It has an average rainfall of approximately 1300 mm, an average annual temperature of 22°C.. The
with a pH range of 5.5 to 6.2 (IITA,
http://en.wikipedia.org/wiki/Namulonge (A) and
42 CHAPTER THREE
3Monoxenic culture of Pratylenchus zeae on carrot discs
Abstract
Pratylenchus zeae is widespread on maize in Uganda but studies to aid in screening cultivars for resistance to this nematode have been constrained by lack of a cheap and reliable technique for raising inoculum. Use of excised maize roots to culture P. zeae is laborious in terms of media preparation and ensuring nematode penetration of roots. Sterile carrot discs are more cost effective and relatively less laborious for rearing most root-lesion nematodes but information on their effectiveness for P. zeae is lacking. The objective of this study was to assess the efficiency of sterile carrot discs for mass culturing of P. zeae collected from maize roots. Twenty live nematodes were transferred to the margins of each of 40 sterile carrot discs contained in 3.5 cm diameter sterile glass Petri dishes. All cultures were maintained in the dark at 25 ± 1°C. The reprod uction of the nematodes was assessed three months after inoculation, when the nematodes accumulated on the surface of most carrot discs and the Petri dish surface. The study revealed a mean density of 63 913 vermiform P. zeae comprising 46% females, 54% juveniles and no males. Overall reproduction rate of P. zeae was 5 090 times, whereas the females alone increased by a factor of 1 476. Therefore, use of carrot discs to culture P. zeae results in higher reproduction rates compared to excised maize roots.
Key words: Mass rearing, Reproduction, Root-lesion nematodes.