Nutrient deficiency symptoms in yams (Dioscorea spp.)

Abstract

Symptoms of nutritional deficiencies in D. alata and D. rotundata were observed when yam plants were grown in nutrient solutions from which any of the following had been omitted: N, P, K, Ca, Mg, Zn, Fe, B, Mn, Cu and Mo. The symptoms of deficiency of major elements were visible on plants of both species. The omission of Fe, B and Mo produced characteristic symptoms on the leaves of D. rotundata, but D. alata showed symptoms only in response to Fe deficiency. The omission of minor elements led to poor growth of the leaves, stems and roots. Nutrient deficiencies in yam plants could be diagnosed by visual symptoms in the field.

Iron toxicity symptoms in yams (Dioscorea spp.) grown in water culture

“…At 15 to 60 mg l -1 leaves of TDa 95/00361 contained high levels of Fe and TDr 89/02565 leaves had high levels at 40 to 60 mg l -1 Fe. The levels of N, P, K, Ca, Mg, Zn, Mn and Cu in the leaves of D. alata and D. rotundata were similar to those reported by Shiwachi et al (2004). Fe accumulation in the leaves was higher in D. alata and lower in D. rotundata leaves than in previous report when Fe was applied at high concentration (Shiwachi et al 2004).…”

“…The solution with a full complement of nutrients, 0.81 g l -1 KNO 3 , 0.94 g l -1 Ca(NO 3 ) 2 .4H 2 O, 0.49 g l -1 MgSO 4 .7H 2 O, 0.21 g l -1 NaH 2 PO 4 .2H 2 O, 3 mg l -1 H 3 BO 3 , 0.22 mg l -1 ZnSO 4 .7H 2 O, 2 mg l -1 MnSO 4 .4H 2 O, 0.05 mg l -1 CuSO 4 .5H 2 O, 0.02 mg l -1 Na 2 MoO 4 .2H 2 O and 15.1 mg l -1 Fe-EDTA (3 mg l -1 of Fe) used for water culture in yams (Shiwachi et al 2004) served as the control. It had pH 6.5 and EC 2.2 mmho.…”

“…In studies on nutrient deficiencies, the omission of N, K, Ca or S led to poor growth of D. rotundata in sand culture (Gaztambide and Cibes 1975). Shiwachi et al (2004) reported heavily stunted growth of D. alata and D. rotundata in water culture due to the omission of N, P or Ca. The optimal pH for yam growth is between 6 and 7 and problems of aluminium toxicity can occur below pH 5.5 that would require calcium enrichment (Gaztambide and Cibes 1975).…”

Evaluation of White yam (Dioscorea rotundata) genotypes for arbuscular mycorrhizal colonization, leaf nutrient concentrations and tuber yield under NPK fertilizer application

“…Positive correlation was observed between tuber yield and leaf concentrations of N, P, K, and Mg. This reaffirmed the importance of these nutrients in yam as stated in other studies (Obigbesan, 1981;Shiwachi et al, 2004).…”

“…While leaf K concentration ranged from 2.52-3.25% in TDr '97/00609', it was 1.61-1.85% in TDr '93-32' even at 600 kg ha −1 NPK application. The range of leaf Zn concentration observed in the present study was within the range reported by Shiwachi et al (2004) when yam varieties were grown in nutrient solution. However, lower ranges were observed for Ca and Mg in our study.…”