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ARS Home » Northeast Area » Beltsville, Maryland (BARC) » Beltsville Agricultural Research Center » Sustainable Perennial Crops Laboratory » Research » Publications at this Location » Publication #314073

Research Project: Sustainable Production Systems for Cacao

Location: Sustainable Perennial Crops Laboratory

Title: Macro and micro nutrient uptake parameters and use efficiency in cacao genotypes influenced by deficient to excess levels of soil K

Author
item LI, YAN-MEI - Southwest University
item Elson, Marshall
item Zhang, Dapeng
item HE, ZHENLI - University Of Florida
item Sicher, Richard
item Baligar, Virupax

Submitted to: International Journal of Plant and Soil Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/7/2015
Publication Date: 4/22/2015
Publication URL: http://handle.nal.usda.gov/10113/63028
Citation: Li, Y., Elson, M.K., Zhang, D., He, Z., Sicher Jr, R.C., Baligar, V.C. 2015. Macro and micro nutrient uptake parameters and use efficiency in cacao genotypes influenced by deficient to excess levels of soil K. International Journal of Plant and Soil Science. 7:80-90.

Interpretive Summary: Cacao (Theobroma cacao L.) is an important economic crop in several tropical counties, but its yields can be limited because of low potassium (K) levels in the soil. In this paper we report influence of deficient to excess levels of soil K on macro and micro nutrient uptake parameters and use efficiency in cacao genotypes. Significant effects of K were found in the concentration, uptake, transport, influx and efficiency ratios of macro and micro nutrients in cacao. Significant increases in use efficiency for N, P, Ca, Mg, B and Mn, and decreases in use efficiency for K and Zn were observed with increasing soil K levels. Knowledge gained from this research on K nutrition and its use efficiency in cacao genotypes will aid resource limited tropical cacao farmers to plant suitable cacao genotypes to match their soil fertility status and in development of suitable fertilizer management practices to improve cacao yields. Further findings of this research will help plant breeders in breeding cacao varieties efficient in utilization of soil K in environments with a limited supply of available K.

Technical Abstract: Cacao (Theobroma cacao L.) is an important economic crop for many of the tropical countries. Adequate levels of soil K are essential for good growth and achieving high cocoa bean yields. Soils under cacao invariably have low levels of plant available K to support good cacao growth. Growth chamber experiment was conducted to assess the effects of soil K levels on nutrient uptake parameters of cacao genotypes. Significant effects of K were found in the concentration, uptake, transport, influx and efficiency ratios of macro and micro nutrients in cacao. Increasing K in the soil significantly increased the K and Zn concentrations and reduced the P, Ca, Mg, and Mn concentrations in cacao plants. Concentrations of K had significant negative correlations with shoot concentrations of Ca, Mg, P, B, and Mn. Overall uptake of P, Ca, Mg, Fe, and Mn decreased and uptake N, K, Cu and Zn increased with increasing soil K levels. Significant increases in efficiency ratios for N, P, Ca, Mg, B and Mn, and decreases in efficiency ratios for K and Zn were observed with increasing soil K levels. Overall at all soil K levels, cacao genotype, Amelonado was efficient in utilization of absorbed Fe, Mn and Zn and ICS 95 genotype was most efficient in utilization of absorbed N, P, Ca, Mg, B, and Cu. The three cacao genotypes used in this study had similar responses of growth and nutrient uptake parameters to varying growth medium K levels. Understanding of K nutrition and its use efficiency will aid in the development of suitable crop management practices and further assist in breeding of cacao varieties efficient in utilization of soil K in environments with a limited supply of available K.