Effect of nitrogen fertilizer on tea yield and yield components in supplemental irrigation and rainfed conditions

In order to investigate the effect of nitrogen fertilizer on tea yield and yield components in supplemental irrigation and rain fed conditions an experiment was conducted at Feshalam Tea research station in Fouman (Guilan) during (2008-2010). In this study, line-source irrigation technique and the strip plot experiment on randomized complete block design was used. Six levels of nitrogen, zero, 100, 200, 300, 400 and 500 kg ha-1 (N0 to N5) from urea as the main plots and five contiguous irrigation levels consist of full irrigation (I4), deficit irrigation (I1, I2, I3) and no-irrigation (I0) in four replications as sub-plots were arranged. The results showed that supplementary sprinkler irrigation and nitrogen fertilizer increased the number of harvested shoots in the months of water shortage during growing season. Full irrigation (3424 m3) with less nitrogen uptake increased dry matter of tea shoots. The highest yield (3928 kg ha-1 of made tea) was obtained with consumption of 200 to 300 kg N ha-1 under full irrigation condition and the lowest yield (788 kg ha-1 without irrigation and fertilizer. Application of 100 to 200 kg N ha-1 produced the highest yield (1672 kg ha-1) in rainfed conditions.