AbstractsLaw & Legal Studies

The Effect of Height and frequency of Defoliation on the growth, chemical composition and nutritive value Guatemala grass (tripsacum laxum, nash).

by Jones Ackor

Institution: Kwame Nkrumah University of Science and Technology
Year: 1978
Record ID: 1512203
Full text PDF: http://dspace.knust.edu.gh:8080/jspui/handle/123456789/1460


The experiment was conducted on the Arable Crops Farms of the University of Science and technology (U.S.T.), Kumasi, Ghana, to find out the effects of height and frequency of cutting on growth chemical composition and the nutritive value of Guatemala grass (tripsacum laxum nash). The experiment was a 3 x 3 factorial design consisting of 3 heights (10, 25 and 40cm) and 3 frequencies (4, 8 and 12 weeks) of cutting. The height and frequency of the treatments were assigned to the plots randomly. Thus there were 9 treatments in each block and these treatments were replicated 3 times. Lax and moderate defoliation gave higher DMY, old tillers (OT), leaf stem ratio (LSR), Crude Fibre (CF) and higher yields of Nitrogen (N), Crude Ash (CA), Digestible Dry Matter (DDM) than severe defoliation. Severe defoliation, however, resulted in higher N, DDM and water Soluble Carbohydrate (WSCHO or Sol CHO) contents of the grass. Height of defoliation had no effect on the weight per tiller, number of new tillers (NT), number of dead tillers (DT), leaf and stem dry matter. Infrequent defoliation gave higher DMY, number of dead tillers, number of new tillers, weight per tiller, increased the leaf and stem dry matter contents and also resulted in higher CF, WSCHO, %DM, number of old tillers and higher yields of nutrients. Frequent defoliation on the other hand, gave higher content of N, CA, DDM, higher LSR and number of old tillers than infrequent defoliation. DMY, weight per tiller, CF, and number of new tillers were higher in the wet season than in the dry season. The DDM and WSCHO were higher in the dry season than in the wet season. CA, N, number of old and dead tillers remained similar in both seasons. Height of defoliation showed significant differences in yield, chemical composition and nutritive value only at the 4-week cutting internal and not at 8 or 12-week cutting interval. Since yield was higher in the wet season than in the dry season, excess fodder in the wet season could be conserved as hay or silage for dry feeding. Severe frequent defoliation resulted in the best quality forage but at the same time led to lower yields and death, especially, towards the latter part of the dry season. It would seem that in order to obtain high yields and good quality fodder, Guatemala grass may be defoliated at a height of about 25cm at 8 week cutting interval. A thesis submitted to the Department of Crop Production, Faculty of Agriculture, University of Science and Technology, Kumasi, Ghana, in partial fulfilment of the requirement of for the M.Sc. (Agric.) Degree, 1978 KNUST