(129) Effect of Foliar Application of Calcium, Boron, and Molybdenum in Nutrient Content of Poinsettia Plants

Abstract

The effect of foliar application of calcium, boron, and molybdenum on macronutrient and micronutrient content of poinsettia (Euphorbia pulcherrima) plants cv. Supjibi was evaluated. Plants were grown under greenhouse conditions in 7-inch containers. Fourteen treatments were applied (10 replicates per treatment); these were formed by three calcium levels (calcium nitrate at 300, 400, and 500 mg·L-1), boron (borax at 0.2, 0.5, and 0.8 mg·L-1), and molybdenum (sodium molybdate at 0.3, 0.4, and 0.5 mg·L-1) and their combinations. Plants were spayed three times during the growing period: 51, 72, and 94 days after transplant. Plants were covered with black polyethylene from 5 pm to 7 am every day in order to induce bract development. N, P, K, Ca, Mg, B, Mo, Mn, Fe, Zn, and Cu content was evaluated 2 weeks after finishing the induction period. The treatment with a combination of Ca+Mo increased by 26% the N content compared with the control. Application of B+Mo, and Ca+B decreased the P content by 32% and 28%, respectively. Treatment with Ca+B+Mo increased foliar K by 46%. B+Mo increased 72.5% Ca content, 38% Mg, and there was about 75 times more Cu than in the control (2.20 vs. 166.7 mg·L-1). Treatments with Ca and B decreased Mn content by 32.7%. Ca (500 mg·L-1) decreased B content by 76%. Treatments did not have any significance on Mo, Fe, and Zn content. As a general conclusion it can be said that foliar applications of Ca, B, Mo, alone or in certain combinations, affected significantly the content of foliar nutrients due to specific nutrient interactions in plants.