2.2 Measurements and Analysis of Data
For the collection of data, ten plants were randomly tagged two weeks after planting within the plots and the
following parameters were measured;
Plant height: this was measured with a meter tape from the ground level to the collar of the tallest fully
differentiated plants or the tips of tassels at last sampling and recorded in centimetres.
Leaf area index: This was computed by dividing the total area of leaves by the total ground area covered by the
plant.
Number of days to 50% tasselling: By counting the number of days from sowing till half of the total number of
plants per plot attained tasselling.
Total dry matter (g): This was determined by harvesting above ground portion of a plant in each plot every two
weeks and oven drying to constant weight at 700C and the weights recorded.
Weight of ears per plant (g): Corn ears from plants in the net plot were weighed and averaged to represent mean ear
weight per plant and recorded in grammes.
Number of kernels per ear: The number of ears on plants within the subplot were counted and the average taken as
number of ears per plant.
Total grain yield: This was determined by oven drying the threshed seeds from each yield sample to a constant
weight at 700C, weighing the sample and expressing the grain yield in t ha-1.
Pooled yield of both seasons (t ha-1) was calculated as the average yield in both years.
Agronomic efficiency of nitrogen was estimated by finding the yield difference in fertilized and unfertilized plots
and dividing by the quantity of fertilizer nutrient applied.
All the data collected were subjected to analysis of variance using SAS version 9. ANOVA was carried out on the
effects of nitrogen, lime, variety and their interactions on variables measured and mean separation was done using
Student Newman Kuel’s test (P < 0.05).
3. Results
3.1 Plant Height, Leaf Area Index and Number of Days to 50 Percent Tasselling
Increase in the rates of N from 0 – 120 kg N ha-1 significantly increased plant height and leaf area index (LAI) up
to 120 kg N ha-1 in 2009 but not beyond 80 kg N ha-1 in 2010. Lower N rates resulted in significantly longer
number of days to 50% tasselling in both seasons (Table 3). There was no significant difference in plant height at 0
and 1000 kg ha-1 lime rates in 2009, but at 500 kg ha-1 in the second season, lime application resulted in