Growth and yield response of sweetpotato varieties to date of vine cutting in the humid tropics of Umudike, Southeast Nigeria

Two field trials were conducted in 2014 and 2015 at National Root Crops Research Institute, Umudike, Nigeria to assess growth performance and yield responses of two orange-fleshed sweetpotato varieties (Umuspo 1, Umuspo 3) and one white-fleshed land-race (Ex-Igbariam), variety to date of initial cutting of vine (0, 6, 8 and 10 weeks after planting). The trial treatment combinations were laid out as a 3 x 4 factorial fitted in a randomized complete block design with three replications. The results showed that vine cuttings, irrespective of date of initial cutting of vine, produced significantly higher number of branches/plant, leaf area index and vine multiplication ratio. Highest significant (P<0.05) reduction in weed growth and highest storage root weight per plant and root yield were obtained under no cutting of vine treatment in both years compared to the other varieties. Umuspo 1 had more branches, higher leaf area index, shoot biomass, multiplication ratio, number of storage roots and root yield as well as suppressed weeds more relative to the other varieties. However, Umuspo 3 produced the highest amount of carotene content in its storage root flesh while ExIgbariam had the lowest carotene content.Keywords: Orange-fleshed, root yield, shoot multiplication ratio, and variet

Comparative study on the proximate composition of two cocoyam species as influenced by integrated nutrient management in Umudike, Southeastern Nigeria.

Field experiments were carried out in 2015, 2016 and 2017 cropping seasons at the Research Farm, Forestry Research Institute of Nigeria, Eastern Station, Okwuta in Umuahia South Local Government Area, Abia State to determine the effects of integrated nutrient management on proximate composition of tannia (Xanthosoma sagittifolium) and taro (Colocasia esculenta) in Umudike, southeastern Nigeria. Integrated nutrient management comprising 600 kg NPK 20:10:10 fertilizer and 10 t poultry manure per hectare was applied in 2015 and 2017. The residual effects of the treatments applied in 2015 on growth attributes was observed in 2016. At the end of 2017 harvest, one cocoyam plant out of four sampled plants from each of the three blocks/replications was uprooted from fertilized (plot treated with 600 kg NPK + 10 t PM/ha) and unfertilized plots (control plot) and partitioned into leaf, stem and corm fractions. The plant fractions were taken to laboratory for nutrient analysis. The experiment was laid out in 2 x 3 factorial fitted into randomized complete block design where factor A consisted of treated and control plots (2 levels) while factor B comprised plant fractions with 3 levels (corm, petiole and leaf). The results showed that integrated nutrient management significantly affected crude protein concentration, moisture and ash contents of tannia but statistically the same for taro. It also differed significantly on fibre content of both cocoyam species. Integrated nutrient management x plant fraction interaction effects significantly influenced proximate composition of tannia and taro species

EVALUATION OF CASSAVA/SOYBEAN INTERCROPPING SYSTEM AS INFLUENCED BY CASSAVA GENOTYPES

The effects of three cassava genotypes (NR 8212, TMS 91934 and TMS 30572) grown sole or intercropped with soybean were investigated in two field experiments in 2000/2001 and 2001/2002 cropping seasons at Umudike in the lowland humid forest zone of south-eastern Nigeria. The plant height, canopy diameter, number of leaves per plant and leaf area index (LAI) of soybean and cassava were significantly (

Responses of growth, yield and disease assessment indices of taro [Colocasia esculenta (L.) Schott to integrated nutrient management in Umudike, Southeastern Nigeria

A three – year field study was carried out in 2015, 2016 and 2017 cropping seasons at the Forestry Research Institute of Nigeria, Eastern Research Station, Okwuta in Umuahia South Local Government of Abia State to evaluate the responses of growth, yield and disease assessment indices of taro (NCe 003) leaf blight to various combinations of poultry manure and NPK fertilizer. The experiment was factorial laid out in randomized complete block design with three replications. Factor A was poultry manure which consisted of three levels of 0, 5 and 10 t ha-1 while factor B was NPK 20: 10: 10 fertilizer and comprised also three levels of 0, 300 and 600 kg ha-1 to get nine treatment combinations. Data were taken on the following crop attributes: Leaf area/plant, leaf area index/plant, dry matter yield, harvest index/plot and assessment of cocoyam disease/plot. Results obtained showed that response to integrated nutrient management was statistically the same for most of the measured attributes. However, the interaction between 600 kg ha-1 fertilizer x 5 t ha-1 PM gave the highest significant difference (p≤0.05) on the leaf area (261.80 m2) at 16th week after planting (WAP) in 2017 cropping season. In 2016, the residual effect of poultry manure significantly (p≤0.05) increased the corm dry matter production (26.89 g) and harvest index (77 %) from the plots that received 10 t ha-1 poultry manure in 2015.Conclusively, this study shows that application of 10 t ha-1 poultry manure which significantly affected leaf area index (LAI), increased dry matter yield (DMY) and harvest index (HI) of taro which are good descriptors for assessing crop yield