Abstract

Cuscuta campestris (field dodder) is an obligate shoot parasite weed causing growth inhibition and yields losses of many agricultural crops worldwide. C. campestris is often observed in many crops; among is cassava in the eastern part of the Democratic Republic of Congo. In 2014, subsistence farmers realised that it may be responsible for yield reduction of many crops. This study evaluates the effect of C. campestris on the yield of a bio-fortified cassava. Six quadrats were installed in an existing 2 ha cassava field. In each quadrat, cassava plants infected by C. campestris were marked while in the same quadrat all other non-infected plants were controls. Yield parameters of 40 infected plants were compared to parameters from 43 uninfected plants. At the harvest time, the number of tubers by plant, fresh weight of tubers, tuber diameter, tuber length, and tuber dry weight were measured. Treatment means were separated using the least significant difference test at 5% probability level and the relative yield loss per cassava plant was estimated. Tuber diameter, tuber length and tuber dry weights were significantly reduced in C. campestris infested cassava as compared to controls (pV<0.001).  C. campestris caused substantial estimated yield losses of 48% per plant. The number of tubers was not reduced (pV=0.281), likely because C. campestris appeared six months after the planting date, when the tubers number was already set.

Key words: Cuscuta campestris, cassava, yield, yield loss, field dodder, Democratic Republic of Congo.