Correlations between cactus pear (Opuntia spp.) cladode nutrient concentrations and fruit yield and quality
[Thesis]
M. R. Karim
P. Felker
Texas A&M University - Kingsville
1994
105
M.S.
Texas A&M University - Kingsville
1994
A non-irrigated field trial in Texas examined the influence of N, P, K and micronutrient fertilization on the fruit yield and quality of Opuntia clones selected for fruit production. Six Mexican fruit producing accessions from 4 species Opuntia ficus-indica (accessions 1277, 1376 and 1392), Opuntia hyptiacantha (accession 1287), Opuntia streptacantha (accession 1281) and Opuntia megacantha (accession 1380) were selected for intensive study. A 100 kg ha application of N, P, K did not significantly (p >.05) influence fruit yield, but it significantly (p =.024) increased the fruit sugar (soluble solid) content. Correlation analyses were done between cladode concentrations of N, P, K, Ca, Mg, Na, Fe, Zn, Mn and Cu at the 'whole plant level'. A second experiment was conducted to determine the 'cladode level' correlations between cladode nutrient concentrations and fruit number per cladode of accessions 1277, 1287, 1294 (Opuntia ficus-indica), 1376, and 1380. Paired values of fruit number per cladode and nutrient content per cladode were used to compute 'cladode level' correlations. For K, the 'cladode level' correlation was negative (p = <.05) for 2 of the 5 accessions, while the 'whole plant level' correlation was positive (r =.432, p =.044). The negative 'cladode level' correlation has been attributed to export of large quantities of K from cladodes to fruits. For two accessions (accession 1294 and 1376), fruit number per cladode was correlated with cladode P concentrations (p = <.05) at 'cladode level'. (Abstract shortened by UMI.)