Two greenhouse experiments were carried out to evaluate the effect of lime on soil pH, Mn level and Al saturation and growth, dry matter production and foliar nutrient content in 6-month old cacao (Theobroma cacao L.) plants. A factorial randomized complete block design (4 genotypes x 5 treatments) was replicated 5 times. Two Ultisols from the humid zone of Puerto Rico were used. A Dystropeptic Tropudult (Maricao) with a pH of 4.8, high in Al, received four levels of lime (0, 4, 8 and 12 meq/lOOg of Ca as Ca(OH)2), and one treatment of 4 meq/lOOg Al as A12(S04)3. A Plinthic Palehumult (Torres) with a pH of 4.9 high in Mn, received four lime levels (0, 3, 6, and 9 meq/100 Ca) plus a treatment of 170 mg/kg Mn as MnSO*. Liming reduced extractable Al, Mn, P and Mg in both soils. Growth of 6-month old seedlings increased as Al and Mn decreased. Foliar P, Ca and Mg increased with liming and Al, Mn and Zn decreased. The leaves of the Al-toxic plants were small and chlorotic. In treatments where toxicity of Mn was observed, leaves had 4000 to 6000 mg/kg Mn. Young leaf interveinal areas were chlorotic and older leaves, stems and apical meristems had necrotic spots.


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