Call Prefix : PR-T

Call Suffix : 1992

Call Cutter : D - Hort 14

Location : SEARCA Library

Format : TD

Publisher : Central Luzon State University,

Publication Date : November 1992

Publication Place : Muñoz, Nueva Ecija, Philippines :

Summary : The study was conducted to determine the nutritional status and productivity of carabao mango trees regularly induced with potassium nitrate when fertilized and applied with indole acetic acid. The treatments evaluated were: Zinc (Zn) and Calcium (Ca) application; nitrogen (N), phosphorus (P), potassium (K) or NPK levels, 0-0-0, 0.4-0.4-0.0, and 0.8-0.8-0.8 kg N, P2O5, and K2O, respectively; per tree and IAA application. The experimental trees were 35 years old and induced regularly with potassium nitrate. Significant interaction effects were observed on the number of fruits and yield per tree. The trees applied with Zn (0.5 kg ZnSO (subscript 4)/tree) and 0.8,-0.8, -0.8 kg N, P (subscript 2) O (subscript 5), and K (subscript 2) O, respectively but not sprayed with IAA produced the highest number of fruits (1176.5) and fruit yield (214.70 kg) per tree. The trees applied with Ca but without NPK and sprayed with IAA registered the least number of fruits (22.5) and the lowest yield (4.7) kg per tree. The application of N, P, and K significantly increased pH of ripe fruits from 4.77 in the control (0-0-0) to 4.96 and 4.98 in those applied with 0.8-0.8-0.8 and 0.4-0.4-0.0 kg N, P (subscript 2) O (subscript 5), and K (subscript 2) O/tree, respectively. However, the application of different levels of NPK, and Zn and Ca did not increase significantly the level of N, P, K, Ca, magnesium (Mg), Zn, copper (Cu), Manganes (Mn), and iron (Fe) contents of the leaves of flower induction and after harvest. A significant increase in N, P, K, Zn, and Cu contents of the leaves were observed from fertilizer application to flower induction; but the level of N, K, and Cu after harvest did not differ significantly from that before fertilizer application. The Mg level after harvest was significantly lower than before fertilizer application. On the other hand, Ca and Fe contents before fertilizer application was significantly higher than at flower induction and after harvest. A significant positive correlation was observed.