A survey was carried out in 108 fields in Rwanda to identify constraints to banana productivity in three regions: Ruhengeri (young volcanic soils), Gitarama–Butare (soils derived from granitic rocks), and Kibungo (weathered soils from schistose materials). Data were recorded for the single cultivar Intuntu (AAA)EA). We recorded management practices, and measured nutrient contents in plant and soil, root health parameters and nematode populations. Bunch weights were estimated (r2 = 0.6?) using plant girth and number of fingers. Yield differences were caused by two major factors: soil fertility and management standards. The cation exchange capacity of soils (range: 5-40 cmolc kg-1) was directly governed by organic matter content. Leaf K concentration was strongly related to soil exchangeable K level. Potassium and nitrogen deficiencies were widespread especially in Butare) Gitarama where most soils exhibited exchangeable K levels below 1.5 cmolc kg-1. Two key parameters emerged from management practices: mulching and plant density. The thickness of mulch was significantly higher in Kibungo (leading to more yield???). Plant density was the major factor affecting banana yield: the highest densities (3501 plants/ha) and yields (53.6 t/ha, cycle) were recorded in Ruhengeri, followed by Butare (2631 plants/ha, 27.4 t/ha, cycle) and Kibungo (1600 plants/ha, 25.6 t/ha, cycle). Intercropping had no effect on banana yield. The population density Pratylenchus goodeyi mostly ranged between 0 and 80,000 nematodes/100 g root. We did not detect any evidence of direct impact of nematode population on banana yield.

Plant Production; Pests Of Plants; Soil Fertility

Banana Production Constraints; Plant Density; Nematodes; Soil Fertility; Yield

Africa; East Africa

Rwanda