| Disease | THREE COMBINATIONS OF AMMONIUM SULFATE,DOUBLE SUPER PHOSPHATE AND POTASSIUM CHLORIDE (0,10,20 KG N/RAI, 0,5,10 KG P205/RAI AND 0,10 AND 20 KG K20/RAI,MAKING 27 COMBINATIONS) WERE APPLIED TO MINT PLANTS GROWN IN NAN PROVINCE,THAILAND.
ALL THE P AND K FERTILIZERS WERE APPLIED ONE DAY BEFORE PLANTING WHILE N APPLICATION WAS SPLIT:ONE-HALF OF N FERTILIZER WAS APPLIED AT THE SAME TIME AS P AND K: THE OTHER HALF WAS APPLIED AFTER THE FIRST HARVEST.
RESULTS SHOW THAT N INCREASED FRESH + DRY WEIGHTS ON MINT AND ALSO THE TOTAL OIL PRODUCTION, APPLYING 10 KG N/RAI GAVE THE HIGHEST YIELD AND OIL PRODUCTION AT FIRST HARVEST WHILE APPLICATION OF 20 KG N/RAI GAVE SIMILAR RESULTS IN THE 2ND HARVEST.
P AND K HAD NO EFFECT ON THE MINT YIELD AND OIL PRODUCTION, HOWEVER, N AND P SHOW SYNERGISTIC EFFECTS. |