Waterapple [Syzygium aqueum (Berm. f.) Alston], a member of the family Myrtaceae, is a tropical fruit plant cultivated in Assam, Meghalaya and, to a limited scale in West Bengal. Water apple is locally called jamrul, gives handsome returns to farmers of North 24-Parganas district of West Bengal. The crop has also been popularized in red laterite zone of West Bengal. The taste of the fruit is very good due to dry climatic conditions prevalent during flowering and fruiting. The crop is conventionally propagated by layering but success rate is said to be low (Biswas and Roy, 1983). As no investigation has been made in the red lateritic zone of West Bengal, where the climate is completely different from that in other parts of the state, an experiment was set up to find out congenial time for air layering in water apple. The experiment was conducted in a private orchard at Jhargram, Paschim Midnapore, West Bengal. Air layering was done on 10th and 25th of every month from June to November in 2004 and 2005. Eight-year old water apple plants were used in the study. Each time, thirty layers were prepared with three replications in a randomized block design on 10-12 month old shoots of 3.5 cm diameter. The layers were detached from the plant when roots were clearly visible. Five rooted layers from each replication were selected randomly for recording observations. The remaining layers were planted in polybags and placed in the nursery for studies on field establishment. Data on establishment was recorded 90 days Effect of season on success of air layering in water apple in red laterite zone of West Bengal S. N. Ghosh Department of Fruits and Orchard Management Faculty of Horticulture Bidhan Chandra Krishi Viswavidyalaya, Mohanpur-741252, India E-mail: profsnghosh@rediffmail.com ABSTRACT An experiment was conducted during 2004-05 on farmers’ field at Jhargram to work out optimum time for air layering in water apple. Results revealed that air layering performed during June and July resulted in highest rooting success (100%) with maximum field establishment (100%). Considering overall performance, the months of June and July can be recommended for air layering in water apple in red laterite zone of West Bengal. Key words : Air layering, water apple, season, West Bengal after detachment. Data on root number of layers, time taken for separation of layers, root growth and establishment of layers were collected and statistically analyzed. Data presented in Table 1 indicate that the highest number of rooted layers (100%) was recorded when layering was done from 10th June to 25th July, whereas establishment percentage was maximum (100%) from 10th June to 25th August, followed by 10th September. After 10th September, it showed a decreasing trend and was zero on 10th November, when rainy season completely ceased. It was interesting to note that the percentage of rooted layers in water apple was maximum during the rainy season. Meteorological data (Table 2) indicate that a maximum temperature of 40.3oC and a minimum of 25.2oC, with relative humidity of 95% at 7.00 am and 51% at 2.00 pm are congenial for getting higher percentage of rooted layers of water apple in the red laterite zone of West Bengal. The maximum percentage of rooted layers was recorded in rainy season (June to July); this may be attributed to the prevalent favourable weather conditions which fostered better root formation and development. Suitability of air layering in rainy season (June to September) in many fruit crops has also been advocated earlier by many workers (Sharma and Grewal, 1989; Ghosh, 1998; Ghosh and Banik, 2008). For separation of rooted layers from the mother plant, a minimum of 80 days were required during September-October, while, during June-July, it took a maximum of 110 days. Short communication J. Hortl. Sci. Vol. 3 (2): 164-165, 2008 165 Field establishment of rooted layers is considered to be an important observation in any layering experiment, as, the ultimate aim is to get maximum number of plant surviving under field conditions. Results from Table 1 indicate that establishment of rooted layers was highest (100%) when the operation was done during 10th June to 25th August, followed by 10th September, and, it reduced thereafter. It is clear from data in Table 1 that root growth was maximum in layers prepared on 10th July which resulted in highest root number (11.5) and longest root length (11.6 cm), followed by 25th July. Considering the production of maximum number of rooted layers and their establishment, the months of June and July are the best, followed by August, for air layering in water apple in red laterite zone of West Bengal. REFERENCES Biswas, S. and Roy, B.N. 1983. Induction of rooting in air- layering of water-apple by auxin and non-auxinic chemicals. Punjab J. Hort., 23: 209-211 Ghosh, S.N. 1998. Studies on vegetative propagation in sweet orange (Citrus sinensis Osbeck) cv. Mosambi. The Hort. J., 11: 21-28 Ghosh, S.N. and Banik, B. C. 2008. Effect of season on success of air layering in acid lime grown in red laterite zone of West Bengal. Environ. Eco., 26: 1204- 1205 Sharma, R.C. and Grewal, G.P.S. 1989. A note on propagation studies in litchi (Litchi chinensis Sonn.). Haryana J. Hortl. Sci., 18: 74-76 Table 2. Meteorological data during the period of investigation Month Temperature (0C) Humidity (%) Rainfall Number of Maximum Minimum Maximum Minimum (mm) rainy days 1st to 15th June 40.3 28.7 81 51 11.4 1 16th to 30th June 37.7 27.5 87 58 154.1 4 1st to 15th July 32.0 25.2 94 80 199.6 7 16th to 31st July 33.2 25.5 95 75 119.4 7 1st to 15th August 33.4 26.3 90 68 142.7 5 16th to 31st August 34.1 25.7 94 66 203.2 5 1st to 15th September 32.9 25.4 95 78 211.0 7 16th to 30th September 33.4 25.2 94 71 33.0 3 1st to 15th October 33.2 23.8 97 69 178.7 4 16th to 31st October 29.8 22.5 95 75 18.3 2 1st to 15th November 30.8 16.8 90 47 0 - 16th to 30th November 29.5 12.9 90 39 0 - Table 1. Effect of season on success of air layering in water apple* Date of layering Number of rooted Days taken for Number of Length of Establishment layers (%) detachment of layer (days) roots/layer longest root (cm) of rooted layer (%) 10th June 100 (84.26) 110 10.0 8.5 100 (84.26) 25th June 100 (84.26) 110 10.8 10.0 100 (84.26) 10th July 100 (84.26) 100 11.5 11.6 100 (84.26) 25th July 100 (84.26) 95 11.0 11.0 100 (84.26) 10th August 85 (67.21) 95 11.2 9.0 100 (84.26) 25th August 80 (63.43) 90 9.0 8.4 100 (84.26) 10th September 60 (50.77) 80 7.0 7.0 95 (77.08) 25th September 35 (36.27) 80 5.0 5.2 60 (50.77) 10th October 30 (33.21) 80 3.4 4.0 60 (50.77) 25th October 25 (30.00) 80 3.2 3.8 60 (50.77) 10th November 0 (0.00) - - - 0 (0.00) 25th November 0 (0.00) - - - 0 (0.00) S.Em ± 1.4 2.0 0.2 0.2 1.9 C.D. (P=0.05) 4.2 5.8 0.6 0.5 5.6 Figures in the brackets are angular transformed value * The results are the average of 2004 and 2005 (MS Received 28 December 2007, Revised 23 September 2008) Air layering in water apple J. Hortl. Sci. Vol. 3 (2): 164-165, 2008