Growth and Yield Response of Two Onion (Allium cepa L.) Varieties to Organic and Inorganic Fertilizers in the Forest- Savannah Transitional Zone of Ghana

The objective of the experiment was to evaluate the influence of organic and inorganic fertilizers on growth and yield of two onion varieties in the transitional zone of Ghana. The experiment was laid out in a split plot design with 3 replications. Two varieties [Bawku Red and Red Creole] were laid as main plots and fertilizer rates [10 t/ha Cow dung, 10 t/ha Poultry manure, 300 kg/ha NPK, 5 t/ha PM + 150 kg/ha NPK, 5 t/ha CD + 150 kg/ha NPK) and control (without amendment)] were assigned to sub-plots. The two field experiments were conducted in 2016 and 2017 cropping seasons at the research field of the College of Agriculture Education, University of Education Winneba, Mampong campus. The result showed that Bawku Red planted on 5 t/ha PM + 150 kg/ha NPK produced (P=.05) higher number of leaves per plant and shoot fresh and dry weight than the control during the 2016 cropping season. Red Creole planted on 10 t/ha PM had higher number of leaves per plant, taller plants and higher marketable bulb yield than the control during the 2016 cropping season. In both 2016 and 2017 cropping seasons, Bawku Red and Red Creole planted on 5 t/ha PM + 150 kg/ha NPK produced (P=.05) higher total bulb yield than the control. For maximum vegetative growth and yield in onion production, preferably Bawku red, sole poultry manure (10 t/ha) and/or in combination with NPK (5 t/ha PM+150 kg/ha NPK) is recommended.