~ 3084 ~ Journal of Pharmacognosy and Phytochemistry 2018; 7(4): 3084-3090 E-ISSN: 2278-4136 P-ISSN: 2349-8234 JPP 2018; 7(4): 3084-3090 Received: 09-05-2018 Accepted: 13-06-2018 Khushboo Chandra Department of Plant Breeding and Genetics Dr. Rajendra Prasad Central Agricultural University, Pusa, Samastipur, Bihar, India Anil Pandey Department of Plant Breeding and Genetics Dr. Rajendra Prasad Central Agricultural University, Pusa, Samastipur, Bihar, India SB Mishra Department of Plant Breeding and Genetics Dr. Rajendra Prasad Central Agricultural University, Pusa, Samastipur, Bihar, India Kavita Department of Plant Breeding and Genetics Dr. Rajendra Prasad Central Agricultural University, Pusa, Samastipur, Bihar, India Correspondence Khushboo Chandra Department of Plant Breeding and Genetics Dr. Rajendra Prasad Central Agricultural University, Pusa, Samastipur, Bihar, India Association and cause: Effect of physiological parameters with seed yield among Indian mustard ( Brassica juncea L. Czern & Coss) genotypes under climatological drought condition Khushboo Chandra, Anil Pandey, SB Mishra and Kavita Abstract Modern agriculture is facing multiple challenges including the necessity for a substantial increase, in production to meet the needs of a burgeoning human population. Water shortage is a deleterious consequence of both population growth and climate change and is one of the most severe factors limiting global crop productivity. In order to study correlation and cause effect of deficit irrigation on some physiological traits on yield an experiment on Indian mustard (Brassica juncea L. Czern & Coss), was conducted in Randomized Complete Block Design (RBCD) accommodating 20 genotypes, from various Rapeseed & Mustard centres located across country, randomly in three replications during Rabi 2016-17, one subjected to a drought regime inside the Rainout shelter under residual moisture condition and another one provided with normal irrigated field condition in Dr. Rajendra Prasad Central Agricultural University, Pusa, Samastipur. Analysis of variance revealed considerably exploitable variability for all the 15 traits. Under both conditions of phenotypic correlation revealed that grain yield per plant showed significant and positive correlation with RWC, LMSI, CC, CA, PERO, PRO, RGR, LAI, SLW, OY except ELWL. Phenotypic path coefficient under both condition revealed that all the physiological parameters showed the low direct effect except oil yield showed high direct effect on grain yield per plot. This indicated that improvement in all the physiological parameters which showed significant positive effect and direct effect on grain yield per plot will ultimately enhances the grain yield. Keywords: Brassica juncea L., physiological traits, climatological drought, root parameters, deficit irrigation Introduction Drought stress, as the most important factor limiting growth and yield of crops, affects about 40 to 60 percent of global agricultural lands (Shao et al., 2006; Rashidi, 2013) [12, 10] . In total, drought covers areas of 60 million Kilometres. In the context of agriculture, drought can be defined as the situation in which the amount of water available to the plant in the root zone is less than that required to sustain maximum growth and productivity (Deikman et al. 2012) [5] . Drought avoidance strategies include deep rooting, conservative use of available water and adjustment of life cycle to match rainfall (Touchette et al. 2007) [13] . Among the major food crops, Brassica crops are the most affected by drought due to the fact that they are mainly grown in arid and semiarid areas. Hence, the need for a coherent and long-term planning with the aim of achieving self-sufficiency in edible oils production is undeniable. Yield is a complex, dependent character as it is associated with other morpho-physiological traits that are transmitted quantitatively and more prone to environmental fluctuations than ancillary, independent morpho-physiological qualitatively inherited traits which cumulatively affect the yield expression. Any change in component traits likely to affect the whole network of cause and effect. The intern might affect the true association of traits, both in magnitude and direction and tend to vitiate association of yield and yield components (Biradar et al., 2007) [4] . Material and Methods The experiment consisting of 20 Indian mustard genotypes was planted on 15 th October 2016 under two conditions i.e. no irrigation and normal (two) irrigations, laid out in Randomized Complete Block Design (RCBD) with three replications during Rabi season(2015-16), including check for association and cause-effect study, received from different All India Co- ordinated Research Project- Rapeseed & Mustard centres: DRMR, Bharatpur, Rajasthan, CCSHAU, Hisar, Haryana, BARC, Trombay, Maharashtra, GBPUAT, Pantnagar, Uttarakhand, CSAUAT, Kanpur, U.P, IARI, New Delhi, ARS, RAU, Sriganganagar, Rajasthan and DR.RPCAU, Dholi, Bihar, providing only basal dose of fertilizers i.e.