FFECT OF NITROGEN AND PHOSPHORUS ON THE GROWTH AND YIELD OF LETTUCE

Abstract

An experiment was conducted at the Horticulture Farm of Sher-e-Bangla Agricultural University, Dhaka during the period from October 2004 to January 2005 to study the effect of different levels nitrogen (N) and phsophorus (P205) on the growth and yield of lettuce. The different treatments of nitrogen were control (No), nitrogen 50 kg/ha (N30), nitrogen l 00 kg/ha (N 100) and nitrogen 150 kg/ha (N 1so) as well as different treatments of phosphorus were control (Po), phosphorus 50 kg/ha (P50) and phosphorus 100 kg/ha (P100). The experiment was conducted in the Randomized Complete Block Design (RCBD) with three replications. Data were recorded from ten randomly selected plants of each unit plot on growth and yield of plants. Parameters on plant height, leaves number, leaf area, fresh leaf yield per plant, gross yield, marketable yield, dry matter content and fiber content were studied. Application of different levels of nitrogen and phosphorus significantly influenced the growth and yield of lettuce. The best performance was obtained from N1soP100 treatment combination in case of all parameters that was considered to be the best combination of fertilizer management for maxirmzmg the yield of lettuce. The treatment N150 resulted the highest gross (44.50 t/ha) and marketable yield (43.52 t/ha). The highest gross yield (40 t/ha) was recorded from P100 treatment, while the lowest (35.5 t/ha) was recorded form Po treatment The combined effect of various levels of nitrogen and phosphorus were also found significant m case of yield lettuce. The treatment combination of N1soP100 produced the highest gross (45.50 t/ha) and marketable yield (44.50 t/ha). The lowest gross (32.0 t/ha) and marketable yield (31.0 t/ha) were recorded from the control treatment The benefit cost ratio was maximum (2.97) in the treatment combination of N1soP1oo whereas the minimum (2.18) was recorded from the control treatment (N0Po).