Effects of Filter Cake Fertilization on Weed Infestation, Disease Incidence and Tuber Yield of Cassava (Manihot esculenta) in Swaziland

cassava (Manihot esculenta crantz) is a tuber crop newly introduced in Swaziland. Filter cake is a byproduct of sugarcane processing. In this research, cassava (varieties Nyasa & Line 65) was grown in the field, using filter cake as a fertilizer with the objective to determine the effects of filter cake on weed infestation, disease incidence, insect pest infestation, and storage root yield. Results showed that filter cake improved cassava tuber yields (no filter cake, 400-1,090 kg ha-1; with filter cake, 975-3,510 kg ha-1). Weed infestation was negatively correlated to tuber yield at 12 weeks after planting (WAP) (r = - 0.714; R2 = 0.5098; p < 0.01) and 32 WAP (r = - 0.390; R2 = 0.1521; significant, p > 0.05). Nyasa variety was more infected by cassava leaf mosaic (disease score, 4.5 out of 6.0), than Line 65 (disease score, 2.4 out of 6.0). Insect pest scores were significantly (p < 0.01) higher for Nyasa (insect pest score, 3.8 out of 6.0) than for Line 65 (insect score, 2.0 out of 6.0). The storage root yield (2,893 kg ha-1) of Line 65 was significantly (p < 0.01) higher than Nyasa (1,443 kg ha-1). To conclude, Line 65 is recommended under filter cake application at 60 t ha-1. © 2010 Friends Science Publishers