English - McKnight Foundation Collaborative Crop Research Program

McKnight Foundation Collaborative Crops Research Project No: 06-741
54=Local 3.0 3.5 3.2 4.8 5.0 4.9
Mean 2.5 3.4 3.0 3.7 5.9 4.8
P 0.43 0.60 0.43 0.09
LSD 0.88 1.0 2.40 1.7
CV% 24 21 44 19
Table 9. The effect of genotype on early and late season Cercospora leafspot Incidence (5 plants
affected) and scores (scale 1=clean, 9=severe) of Chitedze Research Station.
Entry Cercospora Incidence Cercospora leafspot infection
Early Late Mean Early Late Mean
5=IT98K-503-1 26.6 72.5 49.6 4.2 6.5 5.4
9=IT97K-7-21-2-2-1 21.3 73.8 47.6 5.8 7.3 6.5
21=IT99K-494-6 27.3 68.9 48.1 5.0 7.0 6.0
37=IT99K-825-15 20.8 73.2 47.0 4.8 6.8 5.8
52=IT82E-16 19.2 64.4 41.8 4.8 6.0 5.4
53=Sudan 27.2 75.2 64.4 5.3 7.2 6.3
54=Local 32.7 70.2 75.2 5.8 6.2 6.0
Mean 25.0 71.2 48.1 5.1 6.7 5.9
P 0.38 0.80 0.44 0.14
LSD 13.3 15.2 1.6 1.0
CV% 36 23 22 11
1.5 Days to flowering and maturity
The variations of cowpea entries on days to 50% flower and to maturity are shown in Table 10 and 11.
Table 10 shows that on average plants flowered earliest at Mpokwa (46 days from planting), closely
followed by Mngwangwa (47 days). Mean date to flowering was most delayed at Lisasadzi in Kasungu,
mainly due to the influence of the local variety which took 89 days to flower. In general Sudan-1 was
the earliest to flower across all sites, followed by IT82E-16. The local entry was the last to flower at
Mngwangwa and Lisasadzi only. In general, there were small differences between flowering dates of the
improved varieties (no more than 10 days), but the farmers highlighted that these differences were
significant and important. Regarding days to maturity, the mean maturity period was shortest at
Mpokwa and Balaka, which was expected. These sites are warmer and drier historically. Apart from
the local entry, entries 9 and 37 had the longest maturity periods of about 77 days. This agrees with
observations in the fields and farmers reasons for disliking the entries. Although these entries were late,
they were inferior in yield compared to the early maturing released varieties. This further suggests good
adaptability for the released varieties.
Table 10. Effect of genotype on days to 50% flower at 5 sites, 2008/09
Entry Mngwangwa Bunda Lisasadzi Mpokwa Balaka Mean
5=IT98K-503-1 46 52 57 46 48 50
9=IT97K-7-21-2-2-1 48 54 59 53 53 53
21=IT99K-494-6 46 52 57 46 47 50
37=IT99K-825-15 47 56 58 53 52 53
52=IT82E-16 44 48 55 39 46 46
53=Sudan-1 46 47 59 41 51 49
54=Local 50 53 89 - 52 61
Mean 47 52 62 46 50 51
P