| dc.description.abstract | Sugarcane is the third most important commodity crop in Kenya after tea and coffee. Though
high yielding and early maturing varieties have been introduced in Kenya Sugar Industry to
overcome low yields, the problem persists. Farmers apply nitrogen either in single dose or split.
It is not known if the rates and mode of application are appropriate for the new varieties. The
industry pays farmers based on tonnage of delivered millable cane, but is considering changing
payment to a combination of yield and quality. It is not known if the payment method shall be
influenced by agronomic inputs and timing of harvesting period. The objective of this study was
to establish the influence of nitrogen fertilizer applied either in single or split to ratoon crop of
new (D8484) and old (C042 I) varieties on soil and leaf nutrients levels, cane yields, quality and
optimal harvesting age. The experimental design was a 2x4x3 split split-plot on a continuation of
a research at Kenya Sugar Research Foundation, Opapo, where the plant crop received similar
treatments. Analysis of soil and leaf nutrients levels, cane yields and quality parameters was
done using recommended methods. The results showed that at start and at harvest of ratoon crop,
the soil pH remained within the range suitable for sugarcane growing. There were no significant
treatment effects on soil P, Ca, Mn, Zn and Fe levels. Only soil K significantly (p:SO.OS)declined
due to variety D8484 at O-IScm at harvest and at both start ofratooning and harvest at IS-30cm
soil depth. Significant (p:SO.OS)leaf %N values were recorded due to varieties from the Sthto io"
MAR. Leaf nitrogen contents in both varieties were similar in the 3rd and 4th MAR, peaked at Sth
MAR and decreased thereafter. Throughout the monitoring period, variety D8484 out-yielded
(p:SO.OS)C042I. Pol%, brix% and sugar yields were significantly influenced by varieties and N
rates. Based on commercial sugar yield, it is concluded that, ratoon crops of varities C042I and
D8484can be harvested at 18thand 1i
h MAR, respectively. Leaf sampling and nutrients analysis
should be done before Sth MAR. Nitrogen rate of 60 kgN/ha may be adopted in order to realize
profitable sugar yield while split application may be done for other reasons like ensuring
uniformity in application and spreading cash flow, but not for yields and commercial sugar
benefit | en_US |
