Selection of best compound fertilizer amended potting mixture for successful growth of black pepper (<em>Piper nigrum l.</em>) hybrid (“Dingirala”) nursery plants
Authors: Devadason R. D. , De Silva C. S. , De Silva Shanthi , Weerawardena T. E. 
Published: July 2023

Black Pepper, Piper nigrum L.) is a perennial, evergreen, climbing vine and it is widely used as a spice and flavoring agent in the food industry and ayurvada medicine throughout the world. Therefore, continuous supply of pepper is important for the sustainability of these sectors. Pepper is usually propagated vegetatively using stem cuttings. Cuttings are planted in polythene bags filled with a mixture of equal parts of topsoil, cow dung, sand, and coir dust. Scarcity of cow dung and expensiveness resulted with huge demand are the limiting factors in commercial production of pepper. Incorporation of nitrogen and phosphorus containing fertilizers to potting mixture in the absence of cow dung may at least supply plant nutrients which highly essential for early growth of plants. Therefore, this study was carried out to investigate the effect of different compound fertilizer for nursery plants of P. nigrum L, hybrid “Dingirala” in the absence of cow dung in the potting mixture. Four different levels (1, 2, 3, 4 g per pot) of four different compound fertilizers were taken as treatments such as T1- Yara Complex (N:P:K 12:11:18), T2- Yara Grower ( N:P:K 21:7:14), T3- NPK Balance (N:P:K 15:15:15) K as SOP, T4- NPK Balance (N:P:K 15:15:15) K as MOP and T5 a phosphate fertilizer Di-ammonium phosphate (DAP) (N:P:K 18:46 :0). All were mixed into a modified potting mixture of topsoil: sand: coir dust 2:1:1 without cow dung. Control was the potting mixture already recommended by Department of Export Agriculture (top soil: sand: coir dust: cow dung, 2:1:1:1) without inorganic fertilizer. Each treatment contained three replicates per treatment. Complete Randomized Block Design (RCBD) was the experimental design and each block consisted with 50 plants. Two nodal cuttings of Black pepper hybrid Dingirala were planted and maintained in a propagator under a net house at central research station Matale (IM3a). After 105 days from establishment, survival percentage, growth parameters such as shoot length (cm), number of leaves and shoot dry weight (g) were measured. Soil parameters such as soil pH and EC and total N%, P% and K% of tissues were analyzed. Significantly highest (P<0.05) survival rate (91%) was recorded from recommended potting mixture used as control in this experiment and cuttings treated with 1g of Di-ammonium phosphate. Significantly highest (P<0.05) shoot length (39.1cm) was recorded from cuttings treated with 1g of Yara complex fertilizer (N:P:K 12:11:18) and Significantly highest (P<0.05) number of leaves (9.0) was recorded from cuttings treated with 1g of DAP fertilizer.Therefore, cuttings planted with top soil: sand: coir dust: cow dung, 2:1:1:1 is the best potting mixture and in absence of cow dung with normal potting mixture with 1g of Di-ammonium phosphate excelled all compound fertilizers in terms of overall growth, soil and leaf nutrient parameters of Hybrid "Dingirala" pepper nursery plants over the first 105 days after establishment.