Effect of Root Pruning and Nitrogen Application on Post Planting Survival, Growth and Establishment of <I>Acacia catechu</I> Willd. Seedlings

Abstract

Containerized/Polybag raised seedlings were root pruned at 0, 5 and 10 cm length from collar regions before planting and given split nitrogen doses of 0, 40, 80 and 120 kg/ha. These conditioned seedlings were studied for morphological, physiological, nutritional status and survival per cent. Root pruning significantly reduced seedling growth and biomass production in monsoon as well as winter planting. Severely pruned (5 cm from collar region) seedlings showed lesser growth and biomass production than light pruned ones (10 cm from collar region) in both planting season. Application of nitrogen up to 80 kg N/ha increased plant growth biomass. Root pruning coupled with nitrogen application improved the morphological attributes and was observed more in light pruned seedlings than severely pruned ones when 80 kg N/ha was applied. Root pruning decreased xylem water potential and root regeneration. Total soluble sugars, starch and carbohydrate content of the transplants increased with increase in severity of root pruning in monsoon planting season, whereas, in winter planting, these reserves increased with increase in root pruning length. Nutrient content and uptake were affected with root pruning length. Nitrogen application increased NPK content and their uptake in the seedlings. Application of 80 kg N/ha in 10 cm pruned seedlings increased the NPK content and their uptake in the seedlings. Survival per cent increased with nitrogen application upto 80 kg/ha and decreased with increase in root pruning severity. Light pruning (5 cm from collar region) with medium application of nitrogen improved the survival percent. In comparison to monsoon, winter transplanting had lower survival per cent in all the treatments.