Annals of Biology 36 (1) : 132-135, 2020 The Response of Dill Plant Morphology and Production Parameters to Different Urea Application Levels when Grown in Calcareous Soil : Correlation Analysis GHAID J. AL-RABADI 1 , SADDAM A. AL-DALAIN 2 , MUSTAFA AL-RAWASHDEH 1 , MOHAMED B. AL-NAWAISEH 2 , AL-RAMAMNEH, EZZ AL-DEIN 2 , JAWAD A. DALAEEN 3 AND HAMMAD K. ALDAL’IN* ,4 1 Department of Animal Production, Faculty of Agriculture, Mutah University, Al-Karak 61710, Jordan *(e-mail : hammadhammad1977@yahoo.com; Mobile : 00962797119618) (Received : October 8, 2019; Accepted : December 15, 2019) ABSTRACT Dill plant is well accepted as an important crop with important usage in the food and pharmaceutical industry. Quantifying production parameters of dill plant after nitrogen fertilizer application is necessary to determine profitability and helps in minimizing environmental pollution. The objective of this study was to predict morphological changes (number of seeds per umbel, number of umbels per plant, number of branches per plant and plant height) and production parameters (1000-seed weight, harvesting index, seed yield, above ground biomass, oil yield and yield content) of dill plants after five different urea application levels (0, 30, 60, 90 and 120 kg/ha). This study revealed the existence of excellent linear correlation between morphological changes and the level of urea application level [correlation value (r) ranged from 0.89 and 99]. This study also showed the existence of an excellent correlation between production parameters and urea application level (r ranged from 0.94 and 97). Under cultivation/climate conditions in this experiment, it can be concluded that the predetermined level of urea fertilizer can predicate morphological changes and production parameters in dill plants. From an economic perspective, the excellent linear fitting can provide a good vision to the usefulness of the application of a predetermined level of nitrogen application. Key words : Dill plant, linear analysis, correlation, production parameters, nitrogen fertilizer 2 Department of Agricultural Sciences of Al-Shoubak University College, Al-Balqa Applied University, Al- Salt 19117, Jordan. 3 Karak University College, Al-Balqa Applied University, Al-Salt 19117, Jordan. 4 Department of Medical Support, Al-Karak University College, Al-Karak, Jordan. INTRODUCTION Dill plant has been reported to possess many important nutritional, pharmaceutical and industrial benefits (Gour et al., 2017; El-Gizawy et al., 2018). Dill plant has significant economic importance as a medicinal herb that possesses many bioactive compounds that have been reported to be useful in human medicine (Yaldiz et al., 2018; Meena et al., 2019). Although there is no available statistics regarding dill production in Jordan, dill produced from the small scale cultivation is not enough to meet local requirements. Different cultivation practices have been adopted in literature to increase the production of dill plants. These practices include manipulation of sowing date, planting distance (i. e. row spacing), the addition of different types of fertilizers, using different levels of same fertilizers and irrigation (Tajpoor et al., 2013; Kadbe, 2016; Popovic et al., 2019). Nitrogen (N) is well known to be the most important nutrient that is required by plants to ensure protein and enzyme synthesis and consequently maintain plant growth and development. Many studies have been conducted to evaluate the influence of N application on production parameters in dill plant (Kadbe, 2016; Gour et al ., 2017). However, the addition of N fertilizers did not always enhance overall dill production. Several factors have been reported to influence N utilization by the plant, such as volatilization, leaching, and denitrification and soil properties (Tajul et al., 2013). From an economic perspective, prediction of dill plant production