Table 1.

Nutrient concentration, water content, and dry matter tuber yield of D. alata and D. rotundata grown in various regions.

Species	Cultivar	Country	Nutrient concentration in yam tuber at harvest, kg t−1 Dry Matter					Moisture content in tuber, kg water t−1 Fresh Matter	Tuber yield, t Dry Matter ha−1	References
			N	P	K	Ca	Mg
D. alata	N/Ma	Kerala, India	15.9	2.0	20.0	ndb	ndb	ndb	4.6	Kabeerathumma et al., 1991
	Brazo fuerte	Abidjan, Côte d'Ivoire	10.2	1.4	9.6	0.5	0.8	76.7	1.9	Budelmann, 1989
	Okinawa white	Miyako Islands, Japan	12.3	2.2	26.7	3.3	2.5	87.7	0.3	Shiwachi et al., 2015
	Gunung	Puerto Rico	19.0	1.6	19.1	5.0	6.0	85.2	8.7	Irizarry et al., 1995
	N/M	Western Nigeria	14.2	1.9	17.9	0.3	0.9	75.2	6.2	Obigbesan and Agboola, 1978
	TDa95/00010	Centre, Côte d'Ivoire	21.0	1.1	18.5	1.0	1.0	80.0	10.0	Diby et al., 2011b
	Mean for D. alata		15.4	1.7	18.6	2.0	2.2	81.0	5.3
	Mean nutrient export per ton tuber Fresh Matter ha−1		2.9	0.3	3.5	0.4	0.4
D. rotundata	N/M	Kerala, India	9.1	1.6	10.9	ndb	ndb	ndb	9.7	Kabeerathumma et al., 1991
	Habanero	Puerto Rico	8.1	1.3	9.5	1.0	1.4	65.1	18.0	Irizarry and Rivera, 1985
	Efuru	Western Nigeria	12.8	1.5	14.5	0.3	0.9	67.2	10.4	Obigbesan and Agboola, 1978
	Aro	Western Nigeria	11.5	1.5	12.7	0.3	0.9	65.6	9.7	Obigbesan and Agboola, 1978
	Obiaoturugo	Benin City, Nigeria	2.2	0.2	1.2	ndb	ndb	63.8	5.5	Law-Ogbomo and Remison, 2009
	TDr95/18544	Ibadan, Nigeria	3.2	1.7	5.9	0.7	1.2	64.0	3.4	Kikuno et al., 2015
	Mean for D. rotundata		7.8	1.3	9.1	0.6	1.1	65.1	9.4
	Mean nutrient export per ton tuber Fresh Matter ha−1		2.7	0.5	3.2	0.2	0.4

N/M^a, not mentioned; nd^b data not provided.