Maize Genetics Cooperation Newsletter vol 88 2014
evaluation of new maize hybrids for yield and adaptation in mt. kenya region.
1 C. Mutinda , , 2Makumbi, D., 1S. Njoka, and 1 Manyara, F.
1 KARI regional Research Centre,Box 27, Embu.
2 CIMMYT Kenya, Box 25171 Nairobi Kenya.
Maize production in MT. Kenya region is constrained by biotic and abiotic factors. The abiotic factors include low soil fertility coupled with low levels of moisture. The biotic ones include diseases and insect pests. In the last seven years or so, development of germplasm for stress tolerance has been going on in the dry mid-altitude ecological zone (800-1400Masl, 250-500mm rainfall.) in collaboration with CIMMYT. The varieties developed have been extensively evaluated in the region. During the Long rains of 2,011 two hundred and ninety (290) varieties were evaluated for yield potential and adaptation in Mt. Kenya region. Results indicate that the newly developed varieties yielded two Tons more than recommended hybrids. These new hybrids were also found to be of good agronomic traits such as ear rots (less than 10%), ear aspect (less than 2.5) and husk cover(less than 10%). It is recommended that these varieties be entered in the official release process as well as some participatory evaluations be done on-farm to fast-track their official release.
Adaptation, yield potential,
1 corresponding author [email protected]
Maize (Zea mays L.) is the most important staple food crop in Kenya. It is grown over a wide range of agro-ecological zones from sea level to over 2100M asl. The average rainfall varies from 250mm to over 2000mm per year. The total land area under maize production is about 1.6 Million hectares. About 70 to 90% of this is in small scale enterprise. Annual production is estimated at 3.3 million Metric Tones.
According to Food and Agriculture Organization (FAO) the area under maize (1972-1992) remained stagnant while production increased by 1.6 per cent due to improved yield, consumption, by contrast increased at a rate of 2.1 per cent a year.
Kenya’s maize improvement programme has identified six main agro-climatic zones, environmental determinants of these agro-climatic zones are elevation, rainfall and temperature (Gebrekidan et al. 1990). The six zones are Low tropics, Dry mid-altitude, Moist Mid-altitude, Dry Transitional, Moist Transitional and High Tropics. Across these ecologies on-farm yield realization is about 2.0 Tonnes per hectare. And in a bimodal rainfall situation farmers may not even harvest during the short rains season (September-December rainy season)
The Kenyan maize programme is principally concerned with the improvement of grain yield, biotic factors such as diseases, insect pests, weeds (striga ssp) and abiotic stresses which include drought and Low soil fertility. Insect pests pose the greatest challenge amongst the biotic factors whilst drought is the problem in the drier parts of the mount Kenya region (KARI/CIMMYT Database, 1994).
In Kenya two Narrow base populations, a Tuxepeno-Derived Kitale station maize collected from farmers fields (Kitale synthetic II ) and a high altitude flint collection, EC 573 form the basis of the maize breeding programme for Kenya, especially in the Moist Transitional, Moist Mid-altitude and the High tropics. There is, therefore, the need for drought tolerant germplasm infusion in the maize programme to address drought issues more-so in the prevailing climatic changes. The objective of this research undertaking was to evaluate newly developed maize varieties for yield potential and adaptation in MT. Kenya region.
Materials and Methods
Thirty (30) trials comprising three way and double cross hybrids, varietal, early-intermediate and intermediate late hybrids were planted at KARI-Embu for evaluation for potential yield and adaptation during the long rains season of March to July 2011 (Table 1.0). KARI-Embu is within the ago ecological zone UM2 (AEZ UM2). The varieties were selected from the Drought Tolerant Maize for Africa (DTMA) project. The spacing was 25cm between plants on the row and 75cm between the rows.
The design was a 2x5 row plots of a (0,1) alpha lattice with 3 replications.Appropriate agronomic practices were practiced as recommended for the mid-altitude region- i.e all varieties were planted with Diammonium Phosphate (DAP) fertilizer applied at the rate of 50kg/ha P2O5 at planting and later top - dressed with CAN at Knee high at the rate of 50kg/ha N. Maize was weeded manually twice. Data on agronomic performance such as anthesis date, Ears per plant, Husk cover, Ear rot and Ear aspect including Grain yield were taken as described in Vivek et al. (2003):-
Grain yield : Shelled grain weight per plot adjusted to 12.5% grain moisture and converted to tons per hectare, Anthesis date as number of days after planting when 50% of the plants shed pollen, Ears per plant as the number of ears harvested per plot divided by number of plants harvested, Husk cover measured as a percentage of plants with ears that were not completely covered by the husks, ear rot as percentage of ears that were rotten at harvest time and ear aspect taken on a scale of 1-5 where 1 = best and 5 = worst in terms of appearance. Data analysis was done using fieldbook statistical models (Marianne Banziger and Bindiganavile S. Vivek, 2007). Four trials which were analysed included ECA ILHT11 (60 entries), 3WHYB-2011-1 (40entries), EIHYB-2011-6 (40 entries), and EIHYB-2011-3 (150 entries).
Results and Discussions
Grain yield and Anthesis date
Grain yield per hectare and Anthesis date as presented in Tables 2.0,3.0,4.0, &5.0 showed significant differences (P < 0.05) among varieties .Most new hybrids did produce yields that were more than two (2) tons per hectare compared to the popular hybrids – H513, Phb 3253, Duma 43, and DK 8031. This could be contributed to the presence of good germplasm in the region which has the yield potential required for MT. Kenya region. The grain yields obtained in this trial for the medium altitude varieties were far much higher than those reported at farm level by Kiruiro et al. (2001), but similar to those reported by Kariuki et al. (1992). Similar observations were made Kangara et al. (2010). The anthesis dates of the new hybrids were not different from those of the popular checks . This means that there are better hybrids with similar maturity as the existing commercial hybrids (Table 2.0 & 3.0). Table 2.0 below shows performance of early intermediate hybrids against the popularly grown hybrids in the region .
Table 3.0 as indicated below shows performance of intermediate hybrids compared to checks in the region.
Most of the new varieties had low percentage of ear rots as opposed to the older varieties in the market and also showed the tendency to have good rating (on a scale of 1-5) for ear aspect, the best ranked hybrid had 1.7 (Table 4.0 & 5.0). An indication of good quality materials in terms of the endosperm content. Table 4.0 below shows various intermediate late hybrids available for the region.
Table 5.0 shows performance of three way elite hybrids against popular checks. Again the ear aspect rating pretty good for the region which means were are getting better quality germplasm.
The hybrids evaluated and found to out yield the popular checks (Phb 3253, DK8031, and H513 ) by two (2) tons or more and were good in terms of agronomic traits observed as ear aspect, ear rot with maturity (anthesis date 72 days) should be selected and tested in the national performance trials which is done by the Kenya Plant Health Inspectorate (KEPHIS) for release to the farmers in the region. At the same time two (2) of the best hybrids from each of the four trials analysed (ECA ILHT11 -60 entries, 3WHYB-2011-1. 40entries, EIHYB-2011-6-40 entries, and EIHYB-2011-3-150 entries) should be tested on-farm for their performance and acceptability before official release. Also, the germplasm used for the development of these hybrids can further be used by our research development partners to mitigate climatic changes in the region which have led to severe droughts. Thus improving the maize production in the Sub-Saharan region.
These trials were supported by the Drought Tolerant Maize for Africa (DTMA) project coordinated by CIMMYT Nairobi, Kenya.The authors would like to thank the CIMMYT team Kenya office for the support. Centre Director KARI Embu for logistical support and the Director KARI for allowing this paper to be published.
 Brhane Gebrekidan, B.M., Wafula and Kiarie Njoroge. Agroecological zoning in relation to Maize Research priorities in Kenya. KARI/ISNAR management training linkage project, proceedings of a workshop, Nov, 19-23,(1990)-Kakamega, Kenya.
 Regional Research Centre, Embu, (1994). KARI/CIMMYT maize database report, maize farming systems in the mid-altitude areas of Kenya. Farmer practices, research and extension, challenges and the potential for increased productivity.
 Kariuki,I.W., Kangara,J.N.N., Marete, G.M., and Wachira, A.M. (1992). On-farm trials on systematic maize defoliation as supplementary feed source for dairy cattle in Embu. Proc, 3rd KARI scientific conference 21-23 Sept 1992 Pan Afric Hotel Nairobi.
 Kiruiro, E.M., Kihanda, F. and Okuro,J.O. (2001). Maizer leaves as fodder: the potential for enhancing feed availability on small holder farms in Kenya.7th Eastern and Southern Africa Regional Maize conference 11-15 Feb 2001 pp 357-462
 Kangara J.N.N. ,D. Friesen, C.J. Mutinda, S. Amboga, and I.N. Mwangi. (2010). Estimation of yield and fodder nutritive value of dual purpose maize using non-destructive methods. E.Afr. Agric. For. J. (2010) 77(1), 31-37
 Vivek B., M. Banziger and K.V. Pixley. 2003. Characterisation of maize germplasm grown in Eastern and Southern Africa: Results of the 2002 regional trials coordinated by CIMMYT. Harare, Zimbabwe..CIMMYT.
 Marianne Banziger and Bindiganavile S. Vivek (2007), Fieldbook: Software for Managing a Maize Breeding Programme. CIMMYT.
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