Effect of Different Plant Growth Regulators on Growth and Establishment of Rangpur Lime (Citrus limonia Osbeck) and Australian Sour Orange (Citrus aurantium) Root Stock Seedlings Srinivasulu A.*, Ramana K.T. Venkata, Lakshmi L. Mukunda, Sudhakar P., Nagaraju R., Gopal K. AICRP on Fruits (Citrus Research Station, Tirupati-517 502, Dr. YSR Horticultural University, (AP) Horticultural College & Research Institute, Dr. YSRHU, Anantharajupet-516105, AP *email: srinivasulu.horti@gmail.com
Online published on 15 December, 2016. Abstract To study the effect of different plant growthregulators on growth and establishment of Rangpur lime (Citrus limonia Osbeck) and Australian sour orange (Citrus aurantium) root stock seedlings this experiment was conducted at AICRP on Fruits, Citrus Research Station, Tirupati, duringyear 2014–2015. Two months old Rangpur lime and Australian sour orange seedlings were selected for transplanting into poly bags consisting of soil, sand and Farm Yard Manure(FYM). In Rangpur lime and Australian sour orange root stock seedlings, highest values of plant height (30.41 cm and 27.74 cm), SCMR (66.46 and 67.74) were recorded in the GA3 @ 200 ppm treatment (T6), followed by GA3 @ 150 ppm (T5) respectively. Highest number of leaves per seedling (45.97, 40.21), stem girth (1.02 and 0.99cm), canopy spread (18.24 and13.87 cm), leaf area per seedling(77.37 and 65.45 cm2), leaf dry weight per plant (6.87 and 6.87g) and total dry weight of plant (13.04 and 12.69 g) were recorded in IAA @150ppm treatment(T9) respectively in both the root stocks. Maximum root growth values were recorded in the IBA root dipping treatments for both the root stocks. Longest tap root (22.50 and 21.30 cm) and number of fibrous roots (142.33 and 138.63) were recorded in root dipping treatment-T1 (IBA 250 ppm). Number of secondary roots per seedling (28.05 and 23.55) and root dry weight per seedling were found highest (3.43 and 3.07 g respectively) with IBA 750 ppm. All parameters were recorded lowest values in control treatment. Hence, it was recommended that for growth of Rangpur lime and Australian Sour orange root stock seedlings root dipping with IBA 250 ppmat thetime transplanting followed byspraying with GA3 150 ppm or IAA @150ppm at monthly intervals was found economical. Top Keywords Growth regulators, Rangpur lime, Australian sour orange, IAA, IBA, GA3. Top |