Avanços na ciência e tecnologia agrícola

Abstrato

Effects of Pre Cutting Nitrogen Application Rate and Time on Seed Cane Quality of Sugarcane (Saccharum officinarum L.) Crop at Finchaa Sugar Estate

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.