“STUDIES ON COMBINED INFLUENCE OF  PRUNING AND EXOGENOUS APPLICATION OF  GROWTH REGULATORS ON FLOWERING AND  FRUITING BEHAVIOUR OF SWEET ORANGE  (Citrus sinensis Swingle) cv. SATHGUDI”

DUPATI ASHOK KUMAR

“STUDIES ON COMBINED INFLUENCE OF PRUNING AND EXOGENOUS APPLICATION OF GROWTH REGULATORS ON FLOWERING AND FRUITING BEHAVIOUR OF SWEET ORANGE (Citrus sinensis Swingle) cv. SATHGUDI”

Date

2019-09-19

Authors

DUPATI ASHOK KUMAR

Publisher

COLLEGE OF HORTICULTURE ANANTHARAJUPETA -516 105, YSR KADAPA DISTRICT ANDHRA PRADESH

Abstract

A field investigation entitled “Studies on combined influence of pruning and exogenous application of growth regulators on flowering and fruiting behaviour of Sweet Orange (Citrus sinensis Swingle) cv. Sathgudi” was conducted at Fruit science block, sweet orange orchard, College of Horticulture, Anantharajupeta, Dr. Y.S.R.H.U. during the year of 2018-19. The experiment was laid out in factorial randomized block design with twelve treatments with single control and replicated thrice. This interaction study was conducted with three major objectives viz, to analyze the combined influence of pruning and exogenous application of PGRs on vegetative growth, initiation of flowering, on fruiting behavior, fruit yield and quality in sweet orange. Among the different interaction treatments tested, to initiate flowering, improve behavior and quality improvement in sweet orange (Citrus sinensis Swingle) cv. Sathgudi, T2 (P1C2 – Pruning 10 cm + NAA @ 100 ppm) recorded less number of days taken for flowering, more number of flowers per shoot, maximum flowering percentage, highest flower retention percentage, maximum fruit set percentage, more number of fruits per shoot, more number of fruits per tree, minimum fruit drop percentage, highest fruit yield per tree, less peel to pulp ratio, highest juice content, maximum total soluble solids, low titrable acidity, more ascorbic acid content and maximum total sugars content. Maximum shoot length and fruit length were recorded in T4 (Pruning 10 cm + GA3 @ 100 ppm). Maximum fruit volume was noticed in T1 (Pruning 10 cm + NAA @ 50 ppm). Minimum number of seeds per fruit was observed under T11 (Pruning 15 cm + 2% KNO3). Maximum fruit weight and highest reducing sugars content were recorded in T9 (Pruning 15 cm + GA3 @ 50 ppm). Highest fruit volume and maximum fruit diameter were measured under T1 (Pruning 10 cm + NAA @ 50 ppm). Less peel thickness and minimum peel weight were noticed under T12 (Pruning 15 cm + 3% KNO3). It can be concluded from the present study, those among all the interaction treatments, T2 (P1C2 – Pruning 10 cm during the second week of September + NAA @ 100 ppm in two sprays during October at fortnightly intervals) was the best for early flowering, fruit growth and development and quality parameters of sweet orange.

Description

In the present investigation an attempt was made to initiate the flowering, improve the fruiting and increase the quality of sweet orange. In this research work combined influence of pruning with different levels and growth regulators with different concentrations for only one season (Hasta bahar) there is need to conduct the same experiment for at least two successive years, since Sathgudi is a good sweet orange cultivar to arrive at concrete recommendation to the farming community. There is need to study the influence at different pruning levels and concentrations of growth regulators in sweet orange as well as all the citrus fruits to know about their influence. There is need to use the different growth regulators and different pruning levels in fruit crops other than citrus Potassium nitrate has the capacity to enhance flowering, fruiting and quality in different crops, so there is need to conduct experiment regarding effect of these chemicals on regulation of flowering and fruiting and quality assessment.