Growth and Yield Analysis using Different Spatial Density in Lactuca sativa Production at Cuttington University, Liberia

Using optimum plant spacing is one of the important agronomic practices to maximize the productivity of lettuce. It enhances high yield due to the methods of planting density used. A field experiment was conducted to assess the responses of lettuce to different plant spacing at the Agricultural Research field, at Cuttington University. Three treatments and three levels of intra-row spacing were studied on one type of lettuce variety. These treatments were used to determine the growth analysis of lettuce taking into account all appropriate agronomy practices with equal applications of plant nutrients. The treatments (20cm X 20cm, 20cm X 30cm, and 20cm X 40cm) were arranged in a randomized complete block design (RCBD) with three blocks and three replications in the experiment. The results revealed that marketable and total fresh yield per plant was significantly affected by the main effect of plant spacing. Increasing planting density increased the total fresh leaf yield per unit area of lettuce. The highest yield was obtained using 20cm x 40cm planting density, this shows that by increasing the planting distance, the crop absorbs soil nutrients. Also, 20cm X 30cm planting density slightly performed but could not accumulate a high yield compared to 20cm X 40cm. However, 20cm X 20cm planting density could not obtain the expected yield outcome due to clustering in the total plant population. Reduction in plant spacing lead to a high plant population and such population are usually clustered. Hence, 20cm X 40cm is an optimum plant spacing to grow lettuce.