| dc.description.abstract |
Breeding for nitrogen use efficiency (NUE) is important to deal with food insecurity and its
effect on grain quality, particularly protein. A total of 1679 hybrids were evaluated in 16 different
trials for grain yield (GY), grain quality traits (protein, starch and oil content) and kernel weight
(KW) under optimum and managed low soil nitrogen fields in Kiboko, Kenya, from 2011 to 2014.
The objectives of our study were to understand (i) the effect of low soil N stress on GY and quality
traits, (ii) the relationship between GY and quality traits under each soil management condition and
(iii) the relationship of traits with low-N versus optimum conditions. From the results, we observed
the negative effects of low N on GY, KW and the percentage of protein content, and a positive effect
on the percentage of starch content. The correlation between GY and all quality traits was very weak
under both soil N conditions. GY had a strong relationship with KW under both optimum and low
soil N conditions. Protein and starch content was significantly negative under both optimum and
low-N conditions. There was no clear relationship among quality traits under optimum and low N,
except for oil content. Therefore, it seems feasible to simultaneously improve GY along with quality
traits under both optimum and low-N conditions, except for oil content. However, the negative trend
observed between GY (starch) and protein content suggests the need for the regular monitoring of
protein and starch content to identify varieties that combine both high GY and acceptable quality.
Finally, we recommend further research with a few tropical maize genotypes contrasting for NUE to
understand the relationship between the change in grain quality and NUE under low-N conditions |
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