Effect of organic fertilizer types and rates on early growth of African walnut (Plukenetia conophora Mull arg)

Abstract

Plukenetia conophora is a multipurpose liana of high economic importance facing serious threat of extinction; therefore to curb this trend,  producing healthy seedlings within good time frame is required. This research was therefore conducted to determine the effects  of compost, poultry and cow dungs and their rates on growth and development of P. conophora. A total of 375 seedlings were applied  three fertilizer types at 5 rates of 0ton/ha, 12.35ton/ha, 24.69ton/ha, 37.04ton/ha, 49.38 ton/ha in 2kg polythene soil filled pots arranged in  completely randomize design in five replicates with five seedlings per replicate. Data collected on length of liana, collar diameter, number of leaves, dry weight, leaf area, relative growth rates, absolute growth rates as well as net assimilation rate were subjected to  descriptive analysis and ANOVA using SAS. Results showed that organic manure types had significant effects on plant collar diameter and  leaf area. The manure rates had significant effects the on plants leaf area. The interactive effect of fertilizer types and rates showed  that the highest leaf area of 127.01cm² was obtained with compost at 49.38ton/ha and followed by poultry waste at 49.38ton/ha while  cow dung was at 37.04ton/ha. It was least for control with value of 99.45cm² . It was concluded that types and rates of the organic manures enhanced the growth and development of P. conophora and were generally optimum at 49.38ton/ha.