Growth and Tuber Yield Performance of Taro Landrances in the face of Taro Leaf Blight (Phytophthora colocasiae Rachib) Outbreak in Nigeria

Abstract

The study was carried out to assess the growth, taro leaf blight (TLB) severity and yield of some taro (Colocasia esculenta (L.) Schott) genotypes commonly grown by farmers in Nigeria across four environments (two locations in two years). The experiment was laid out as a split-split plot in a randomized complete block design with year as main plot, location as subplot and genotype as the sub-subplot in three replications. The eight genotypes used were: NCe 001, NCe 002, NCe 003, NCe 005, NCe 010, NCe 011, NCe 012, and “Ede Orba”. Data were collected on the growth, TLB severity and yield attributes. There was no significant year effect for most of the yield attributes measured. However, significant year effect was observed for cormel weight and taro yield. Location had significant effect on taro yield with Umudike giving the best performance for yield and most of the measured traits. TLB severity measured overtime showed significant location effect at some stages of the disease. The genotypes varied significantly (p<0.001) in their performance for all the traits studied with NCe 010 having the best performance for taro yield and few of other characters. This did not differ significantly from NCe 003 which was the second-best performer for taro yield and best performer for leaf area, number of leaves/plant and corm weight. TLB severity was highest on NCe 001 and NCe 005 at almost all the stages of disease assessment. The study showed that TLB is at its highest severity at 4 weeks after symptom appearance in taro and this incidentally may be a period where it could cause maximum damage to the taro plants. However, genotypes NCe 010 and NCe 003 have shown to give relatively better yield under the widespread severity of TLB ravaging taro fields in Nigeria.