Sseruwu G.,University of KwaZulu - Natal |
Sseruwu G.,Mukono Zonal Agricultural Research and Development Institute MUZARDI |
Shanahan P.,University of KwaZulu - Natal |
Melis R.,University of KwaZulu - Natal |
Ssemakula G.,National Crops Resources Research Institute NaCRRI
Euphytica | Year: 2016
Alternaria blight (Alternaria spp.) is an important sweetpotato disease in Uganda causing yield losses of over 50 % in susceptible genotypes. In Uganda, Alternaria bataticola and Alternaria alternata are the major species with A. bataticola the more aggressive of the two. The most effective control measure for this disease is the use of resistant genotypes. This study was conducted to determine the inheritance of resistance to Alternaria blight and the general and specific combining abilities of the available germplasm. Sixteen parental clones varying in reaction to Alternaria blight were crossed using the North Carolina II mating scheme. Due to incompatibility of some parents, two sets of compatible parents were formed. Differences among the families for Alternaria blight severity were significant while general combining ability (GCA) and specific combining ability (SCA) mean squares were highly significant (P < 0.001) for the disease with GCA sum of squares (SS) being more predominant at 67.4 % of the treatment SS for Set 1 and the SCA SS predominant at 54.0 % of the treatment SS for Set 2. This indicated that both additive and non-additive effects are important in controlling this trait. Some parents with high, negative GCA effects produced families with undesirable SCA effects and the reverse was also true. This implies that the best parents should not be chosen on GCA alone but also on SCA of their best crosses. The wide range in the area under disease progress curve for the families indicated that it was possible to select for highly resistant genotypes. © 2016 Springer Science+Business Media Dordrecht
Semakula J.,Mukono Zonal Agricultural Research and Development Institute MUZARDI |
Lusembo P.,Mukono Zonal Agricultural Research and Development Institute MUZARDI |
Kugonza D.R.,Makerere University |
Mutetikka D.,Makerere University |
And 2 more authors.
Livestock Research for Rural Development | Year: 2011
The relationship between zoometrical measurements and live body weight was determined in indigenous chicken of the Lake Victoria Crescent Agro-ecological Zone in Uganda. A sample of 493 mature birds (342 females and 151 males) was used to measure body length, femur circumference, chest circumference, femur length, femur circumference, shank length, and keel length. The effect of age and sex was significant (P < 0.01) for all measurements. Males showed higher live body weights and other body measurements than their female counterparts (P < 0.01) while all body measurements, increased with age. An average mature male chicken weighed 2.11 ± 0.27 kg while a female weighed 1.48 ± 0.15 kg. Correlation coefficients between body weight and other measurements were high and positive (P < 0.01) except for Body Length and Femur Circumference in females. Chest Circumference was the best single live weight estimator (r = 0.88) closely followed by Body Length (r = 0.81), and Femur Length (r = 0.80) while Femur Circumference (r = 0.29) was the least. Prediction of Live Body Weight from Chest Circumference using the power model (R 2 = 0.83) was the most reliable compared to simple linear regression (0.76) and polynomial (R 2 = 0.77). The strong relationship between Live Body Weight and other body measurements could be exploited to increase the economic value of the indigenous chicken. Determination of live body weights of chickens using the heart girth could earn farmers between $0.6 and $0.65 more while buyers will save between $0.1 and $0.2per kilogram body weight of chicken thus should be encouraged.