Low Soil Nutrient Tolerance and Mineral Fertilizer Response in White Guinea Yam (Dioscorea rotundata) Genotypes

Abstract

Yam (Dioscorea spp.) is a major food security crop for millions of resource-poor farmers, particularly in West Africa. Soil mineral deficiency is the main challenge in yam production, especially with the dwindling of fallow lands for the indigenous nutrient supply. Cultivars tolerant to available low soil nutrients and responsive to added nutrient supply are viable components of an integrated soil fertility management strategy for sustainable and productive yam farming systems in West Africa. This study’s objective was to identify white Guinea yam (D. rotundata) genotypes adapted to available low soil nutrients and responsive to externally added nutrient supply. Twenty advanced breeding lines and a local variety (Amula) were evaluated under contrasting soil fertility, low to expose the crop to available low soil nutrient supply and high to assess the crop response to added mineral fertilizer (NPK) input at Ibadan, Nigeria. The genotypes expressed differential yield response to low soil fertility (LF) stress and added fertilizer input. Soil fertility susceptibility index (SFSI) ranged from 0.64 to 1.34 for tuber yield and 0.60 to 1.30 for shoot dry weight. The genotypes R034, R041, R050, R052, R060, R100, and R125 combined lower SFSI with a low rate of reduction in tuber yield were identified as tolerant to LF stress related to the soil mineral deficiency. Likewise, the genotypes R109, R119, and R131 showed high susceptibility to soil fertility level and/or fertilizer response. Genotypes R025 and R034 had the tuber yielding potential twice of that the local variety under low soil nutrient conditions. Shoot dry weight and tuber yield showed a positive correlation both under low and high soil fertility conditions (r = 0.69 and 0.75, respectively), indicating the vigor biomass may be a morphological marker for selecting genotypes of white Guinea yam for higher tuber yield. Our results highlight genotypic variation in the tolerance to low soil nutrients and mineral fertilizer response in white Guinea yam to exploit through breeding and genetic studies to develop improved genotypes for low and high input production systems in West Africa.

Cross compatibility in intraspecific and interspecific hybridization in yam (Dioscorea spp.)

“…In this region, the yam crop is an integral part of the socio-cultural and religious belief systems. Despite its importance as a staple food crop, source of income 5 , and socio-cultural connection to the society which depends on it, yam productivity has not increased much as compared to other root and tuber crops or cereal and grain crops 2 , 6 . Yam cultivation is challenged by many factors, of which an under-developed seed system is primary.…”

The Effect of Rainfall, Temperature, and Relative Humidity on the Yield of Cassava, Yam, and Maize in the Ashanti Region of Ghana

“…Most studies on maize have dwelled on yield gabs, fertilizer application on yields, one or two climatic conditions effecting yields, and soil and crop management practices [24][25][26][27][28][29][30]. Additional studies on yam have concentrated on soil nutrient tolerance, mineral fertilizer response, stability and adaptability of species, production from tubers and minisetts, and potential returns on investment in research [31][32][33][34].…”

Genome-Wide Association Studies for Sex Determination and Cross-Compatibility in Water Yam (Dioscorea alata L.)

“…Yam yield has, however, remained low over time because of several biotic (diseases and pests), abiotic (drought, low soil fertility, etc. ), and agronomic constraints [ 6 , 7 ]. Developing resistant/tolerant varieties coupled with a robust seed delivery system could be an effective means of raising yields of predominantly resource-poor farmers characterized by low use of external farm inputs.…”