Author : Castillo, Rebecca B.

Summary : Field and greenhouse experiments were conducted from 1989 to 1990 on Paoay sandy loam, La Trinidad clay loam, and Paoay clay loam soils to determine the response of potato to application of boron (B), complete fertilizer, and chicken manure. The soil varied in B levels (0.25 to 0.53 mg/kg). The rates of B used were 0, 1, 2, and 5 mg/kg in the field and 0, 1, and 2 mg/kg in the greenhouse. These were applied either directly to the soil or by and soaking the seedpieces in them. Results of field experiment showed that appliying complete fertilizer at 0.86 t/ha or chicken manure at 20/ha increased total and marketable tuber yields in soil containing medium level of B (0.35 mg/kg). Addition of B at 1 mg/kg had only slight effects. Total and marketable tuber yields were noted when B was applied by seedpiece soaking. Increased addition of B to chicken manure reduced tuber yields. In the field, highest B uptakes were observed with the addition of chiken manure or complete fertilizer plus B (up to 5 mg/kg). Application of complete fertilizer and chicken manure increased potassium uptake while application of complete fertilizer alone increased calcium uptake. Greenhouse tests showed highest total tuber yield with added chicken manure in sandy loam soil with low B (0.25 mg/kg) level. In clay loam soils with medium and high B contents (0.35 and 0.53 mg/kg, respectively), combined treatments with chicken manure and B at 1 mg/kg increased total and marketable tuber yields. Shoot dry weights were higher in soils applied with chicken manure than those with complete fertilizer. B uptakes were increased in the three soils when chicken manure was applied. The order of B uptake in these soils is as follows: low B soil > medium B soil > high B soil. The low B soil was most responsive to fertilization. Less effect of complete fertilizer was observed when seedpieces were soaked rather than when B was applied directly to the soil. In all soils studied, potassium and calcium uptakes were high in shoots when chicken manure.