~ 1310 ~ Journal of Pharmacognosy and Phytochemistry 2018; 7(6): 1310-1315 E-ISSN: 2278-4136 P-ISSN: 2349-8234 JPP 2018; 7(6): 1310-1315 Received: 19-09-2018 Accepted: 21-10-2018 Latha P Senior Scientist (Crop Physiology), Institute of Frontier Technology, Regional Agricultural Research Station, Acharya N G Ranga Agricultural University, Tirupathi, Andhra Pradesh, India Sudhakar P Sri Venkateswara Agricultural College, Acharya N G Ranga Agricultural University, Tirupathi, Andhra Pradesh, India Nirmal Kumar AR Institute of Frontier Technology, Regional Agricultural Research Station, Acharya N G Ranga Agricultural University, Tirupathi, Andhra Pradesh, India Vasanthi RP Institute of Frontier Technology, Regional Agricultural Research Station, Acharya N G Ranga Agricultural University, Tirupathi, Andhra Pradesh, India John K Institute of Frontier Technology, Regional Agricultural Research Station, Acharya N G Ranga Agricultural University, Tirupathi, Andhra Pradesh, India Lavanya Kumari P Institute of Frontier Technology, Regional Agricultural Research Station, Acharya N G Ranga Agricultural University, Tirupathi, Andhra Pradesh, India Correspondence Latha P Senior Scientist (Crop Physiology), Institute of Frontier Technology, Regional Agricultural Research Station, Acharya N G Ranga Agricultural University, Tirupathi, Andhra Pradesh, India Phenotyping of groundnut ( Arachis hypogaea L.) genotypes for physiological and yield traits under mid-season drought stress Latha P, Sudhakar P, Nirmal Kumar AR, Vasanthi RP, John K and Lavanya Kumari P Abstract Two field experiments were conducted during Rabi 2014-15 and 2015-16 to screen 12 peanut genotypes for physiological traits and to study the changes in gas exchange parameters under water deficit condition. The two years data on various physiological and yield traits was collected, pooled and subjected to Repeated Measures mixed Analysis of Variance (RMANOVA) at a probability level of 5 % and Principal Component analysis was carried out using SPSS 20.0software. The physiological traits viz., gas exchange parameters, SCMR, SLA, RWC, RI and CSI of peanut leaves significantly differed among irrigation treatments and genotypes. From the PCs, it was clear that among all the twelve variables, photosynthetic rate, transpiration rate and pod yield are the major source of variation both in T1 and T2 treatments. Our results suggest that the genotypes TCGS 1345 followed by TCGS 1343 are promising genotypes which maintained least deviation on physiological traits and recorded high pod yields under water deficit condition. Keywords: Physiological traits, gas exchange parameters, irrigation, peanut, Introduction Globally, peanut occupies an area of 26.4 m ha with a production of 37.1 m metric tonnes and productivity of 1400 kg ha -1 (FAOSTAT, 2015-2016). It is mainly grown in states like Gujarat, Andhra Pradesh, Karnataka, Tamil Nadu and Maharashtra. In India, peanut occupies an area of 45.78 lakh ha with production of 60.48 lakh tonnes and productivity of 1321 kg ha -1 in kharif. In rabi-summer it is being grown in 7.59 lakh ha with production of 14.14 lakh tonnes with productivity of 1861 kg ha -1 . In Andhra Pradesh, in kharif, it is cultivated in an area of 9.3 lakh ha with production of 3.9 lakh tonnes and productivity of 419 kg ha -1 while in Rabi, cultivated in 0.80 lakh ha with production of 2.12 lakh tonnes and productivity of 2650 kg ha -1 (Indiastat.com, 2016-17). In Andhra Pradesh, it is mostly grown under rainfed situation in Anantapur, Chittoor, Kurnool and Kadapa districts.In India, groundnut is mainly grown in states of Gujarat, Andhra Pradesh, Tamilnadu, Karnataka and Maharashtra, mainly growing under rainfed (kharif) conditions. An area of about 70 percent and 75 percent of the production has been concentrated in the four states of Gujarat, Andhra Pradesh, Karnataka and Tamil Nadu. Andhra Pradesh occupies second place in peanut production, but, the productivity is very low under rainfed conditions (419 kg/ha.) compared to irrigated conditions (2650 kg/ha.). Low rainfall and prolonged dry spells during the crop growth period are the main reasons that cripple the peanut productivity. The farmers of the dry land areas are growing a crop either on rainwater in kharif or on conserved soil moisture during the winter. Most of the crop varieties grown have low genetic potential for yield under low moisture scenario. Many measures have been laid out for selecting a crop variety for dry lands. The ability to produce better yield under limited soil moisture conditions is the most desirable criteria. In other words, crop varieties for dry land areas should be of short duration, drought resistant or tolerant and high yielding which can be harvested with in rainfall periods and have sufficient residual moisture in soil profile for post- monsoon cropping. The drought patterns can be grouped in to three types i.e., early season, mid-season and end of season drought respectively. Mid-season drought affects the most vulnerable stages (pegging, pod and seed development) of plant growth in peanut (Nigam et al., 2003) [23] . Nageswara Rao et al., 1989 [24] observed a poor relationship between the yield potential under adequate water availability and the sensitivity of genotypes to mid-season drought and suggested the