Author(s): Mijena Bikila, Nigussie Dechassa and Yibekal Alemayehu
Field experiment was conducted at Finchaa Sugar Estate during the 2010/11 cropping period to assess the effect of rate and time of pre-cutting nitrogen fertilization on seed cane quality of sugar cane (Saccharum officinarum L.) crop. The treatments consisted of four levels of N (0, 23, 46, 69 kg N ha-1) and four times of N application (8, 6, 4 and 2 Weeks before Cutting (WBC). The field experiment was laid out as a RCBD in a factorial arrangement and replicated three times. A sugarcane cultivar named N-14 was used as a planting material. The experiment was conducted on a sandy clay luvisol. Analysis of variance of the data revealed that the pre-cutting N application rate had no significant main effect on seed cane sett quality at the time of harvest. In contrast, pre-cutting N application time had significant main effect on seed cane stalk height, girth, reducing sugar, moisture and total N content. Thus, treating seed cane with N 8WBC for commercial planting resulted in improvement of seed cane stalk height, girth, reducing sugar and moisture content. However, significant improvement in total N content occurred in response to treating the crop with N 2WBC. The two main factors interacted to significantly influence only seed cane stalk height, reducing sugar and total N content. Pre-cutting N treatment with the rate of 23 kg ha-1 8WBC resulted in higher seed cane height. However, pre-cutting N treatment with the rate of 69 kg ha-1 8WBC resulted in higher reducing sugar and total N content. On the other hand, treating the seed cane with N at the rate of 23 kg ha-1 2WBC resulted in significantly higher total N content, but this value was in statistical parity with the nitrogen content of the seed cane that was obtained from the treatment of 69 kg N ha-1 applied 8 WBC. it was generally observed that early application (8WBC) of N at higher dose (69 kg ha-1) or also late application (2WBC) of N at lower dose (23 kg ha-1) improved seed cane quality through significantly enhancing reducing sugar and total N contents, respectively. Therefore, As the precutting N application rate had no significant main effect, it could be concluded that, treating the seed cane with N at the lower rate of 23 kg ha-1 8WBC had a dual advantage of improving quality (in terms of height, reducing sugar and total N content) of the seed cane crop.
