~ 2332 ~ International Journal of Chemical Studies 2018; 6(2): 2332-2335 P-ISSN: 2349–8528 E-ISSN: 2321–4902 IJCS 2018; 6(2): 2332-2335 © 2018 IJCS Received: 18-01-2018 Accepted: 21-02-2018 Shivangi Arvind Department of Horticulture, College of Agriculture, G.B. Pant University of Agriculture and Technology, Pantnagar, Uttarakhand, India Shant Lal Department of Horticulture, College of Agriculture, G.B. Pant University of Agriculture and Technology, Pantnagar, Uttarakhand, India CP Singh Department of Horticulture, College of Agriculture, G.B. Pant University of Agriculture and Technology, Pantnagar, Uttarakhand, India SK Guru Department of Plant Physiology, College of Basic Science and Humanities, G.B. Pant University of Agriculture and Technology, Pantnagar, Uttarakhand, India Rajesh Kumar Department of Horticulture, College of Agriculture, G.B. Pant University of Agriculture and Technology, Pantnagar, Uttarakhand, India Correspondence Shivangi Arvind Department of Horticulture, College of Agriculture, G.B. Pant University of Agriculture and Technology, Pantnagar, Uttarakhand, India Effect of leaf to fruit ratios on the physico- chemical quality of guava ( Psidium guajava L.) cv. pant prabhat planted under high density Shivangi Arvind, Shant Lal, CP Singh, SK Guru and Rajesh Kumar Abstract An experiment was conducted during years 2016-17 and 2017-18 to determine the effect of leaf to fruit ratio on the physico-chemical quality of guava planted under high density. Plants at four spacing namely S1= 1.0 m x 1.0 m, S2= 1.5 m x 1.5 m, S3= 2 m x 1 m and S4= 2 m x 1.5 m were selected and different leaf to fruit ratio treatments of T1=4:1, T2=8:1, T3=12:1, T4=16:1 and T5=Defoliation of fruiting shoots (appx. 24:1) were imposed on them while untreated trees served as T6= control (appx. 32:1). The results revealed that highest mean fruit weight, fruit length, fruit volume, total soluble solids, reducing sugar and total sugar per cent was recorded in spacing S4. The maximum mean fruit weight, fruit length, fruit volume, total soluble solids and total sugar per cent were recorded in moderate leaf to fruit ratio of T4 and T3. Keywords: leaf to fruit ratio, guava, high density, quality Introduction Guava is a native crop of South America but is now widely grown in almost all the tropical and sub-tropical parts of the globe. Its popularity seems to be increasing with time among consumers who are health conscious as well as farmers who wish to maximize crop productivity with minimum resources. In the present scenario where area for fruit cultivation is constantly decreasing, the concept of high density planting becomes highly relevant. Moreover, guava is the choicest crop for adoption of this practice as it bear fruits on the current season growth and is highly responsive to pruning, both factors very crucial for being planted under high density. However, for achieving the optimum quality of fruits, the proper balance between the source and the sink is quintessential especially under high density plantations, where over shading of the canopy becomes a major problem with time, leading not only to poor quality fruits but also enhancing the risk of pest and diseases in the dense canopy. However, the concept of leaf to fruit ratio is not new, but such studies have been restricted to high value crops like apple, grapes, dates etc. Moreover, it also varies with the species, cultivar and agro-ecological conditions. Orjuela and Barreto (2009) [1] estimated seven leaves (146 cm 2 ) for optimum quality of one fruit of Pineapple guava ( Acca sellowiana Berg). In this purview, an experiment was designed with the objective of examining the effect of various leaf to fruit ratios on the physico-chemical quality of guava under high density planting system and eventually determine an optimum leaf to fruit ratio to be maintained for guava. Materials and methods The present experiment was conducted at the Horticulture Research Centre, Pattharchatta, of G.B. Pant University of Agriculture and Technology, Pantnagar during the years 2016-17 and 2017-18. Seven years old grafted guava plants of cultivar Pant Prabhat planted at four spacing namely S1= 1.0 m x 1.0 m, S2= 1.5 m x 1.5 m, S3= 2 m x 1 m and S4= 2 m x 1.5 m; were selected for the study as per uniformity in growth, shape and vigour. Five treatments of different leaf to fruit ratio ranging from low (T1=4:1, T2=8:1), moderate (T3=12:1, T4=16:1) to high (T5=Defoliation of fruiting shoots with an average leaf to fruit ratio of 24:1) were incorporated while untreated trees served as T6= control (with an average leaf to fruit ratio of 32:1) The experiment was designed in a factorial randomized block fashion replicated thrice giving altogether twenty four treatment combinations. The selected plants were pruned almost to an equal height of about 2 m in the month of February. The treatments were imposed in the