EFFECT OF GROWTH REGULATORS ON YIELD AND QUALITY OF WINTER GUAVA CV. ALLAHABAD SAFEDA

Sandeep Kaur 1 and Amarjeet Kaur 2 . 1. MSc research student Department of Horticulture, Khalsa College, (GNDU)Amritsar-143001. 2. Assistant Professor Department of Horticulture, Khalsa College, (GNDU)Amritsar-143001. ...................................................................................................................... Manuscript Info Abstract ......................... ........................................................................ Manuscript History


ISSN: 2320-5407
Int. J. Adv. Res. 5 (9), 98-103 99 in fruit protects the colon mucous membrane by decreasing the exposure time to toxins as well as binding to cancer causing chemicals in the colon. There is an increasing demand of fruits for fresh as well as processing purpose in domestic and international markets (Bisen et al 2014). The importance of plant growth regulators in achieving higher yield and better quality of fruit crops has been well recognized in recent time. According to Katiyar et al (2008) 2,4-D as well as NAA have been found to accelerate the translocation of metabolites in parts of the plant towards developing fruits and improve their quality by increasing their size, TSS, total sugars and ascorbic acid. Reduction in acidity have also been recorded in guava cv L-49 by the application of 2,4-D and NAA (Garisya et al 2013). The application of urea in guava also improved the quality of fruits (Sahay and Kumar 2004). Keeping in view the above facts the present study was therefore, planned to enhance the quality and yield of guava cv. Allahabad Safeda

Materials And Methods:-
The present study was carried out in the well maintained orchard and analysis was done in the laboratory of Department of Horticulture , Khalsa college, Amritsar during 2016-2017. The experiment was conducted in randomized block design. The experiments comprised of 10 treatments consisting of foliar spray of NAA, 2-4 D and urea. The treatments were T 1 NAA (50 ppm), T 2 NAA (75 ppm), T 3 NAA (100 ppm), T 4 2,4-D (30 ppm), T 5 2,4-D (40 ppm), T 6 2,4-D (50 ppm), T 7 urea (1%), T 8 urea (1.5%), T 9 urea (2%) and T 10 control. Spray was done at 50% flowering stage. The data on chemical parameters was recorded. Chemical parameters of fruits was determined by using average sized 10 fruits collected randomly from each replication. The TSS was determined with the help of a hand refractrometer. Sugars in the fruits were determined by the method given by A.O.A.C. (1990). Ascorbic acid was estimated by indophenols dye method.

Results And Discussion:-
Maximum fruit length (8.92cm) was recorded in the fruits harvested from plants treated with NAA 100 ppm followed by (8.46 cm) with 2, 4-D 50 ppm and (8.16 cm) with 2,4-D 40 ppm respectively. The treatment of NAA 75 ppm recorded the fruit length of (7.61 cm) followed by 2,4-D 30 ppm with (7.53 cm) and NAA 50 ppm with (7.23 cm) length respectively. The data followed the ascending trend in fruit length with an increase in the concentration of NAA and 2, 4-D. The descending trend was noted in the fruit length with an increase in concentration of urea. From the perusal of data it was also clear that urea treatment produced more fruit length as compared to control. Urea 1 per cent produced fruit length of (7.22 cm) followed by urea 2 per cent (6.82 cm) and urea 1.5 per cent with fruit length (6.71 cm) which was more than (6.20 cm) under control.
The fruit breadth was affected significantly by the foliar spray of NAA, 2, 4-D and urea as compared to control. Maximum fruit breadth (9.26 cm) was recorded in the fruits harvested from plants treated with 2, 4-D 50 ppm followed by 2, 4-D 40 ppm and NAA 100 ppm with fruit breadth of (9.10 cm) and (8.93 cm) respectively. The treatments of 2,4-D 30 ppm recorded the fruit breadth of (8.73 cm), which was followed by (8.56 cm) with NAA 75 ppm and (7.70 cm) with NAA 50 ppm respectively. Urea 1.5 per cent produced fruit breadth of (7.11cm) which was followed by (6.96 cm) and (6.72 cm) with urea 1 per cent and urea 2 per cent respectively.
The increase in fruit size (length and breadth) might be due to the optimum supply of plant nutrients and growth regulators in right amount during the entire crop growth period causing vigorous vegetative development of the plant, ultimately leading to production of more photosynthates (Awasthi and Lal 2009). The application of NAA might have a role in increasing the auxin level of fruits, which in turn, might have helped in the development of fruit components as there is a direct correlation between auxin content and fruit growth. Increased level of carbohydrates stimulated cell division and cell elongation resulting in larger fruits. The improved fruit size in terms of length and breadth by plant growth regulators has also been reported by Yadav  The foliar application of NAA, 2, 4-D and urea had beneficial effects on the weight of guava fruit and these chemicals helped in increasing fruit weight significantly over control.The maximum fruit weight (203.00 g) was recorded in the fruits harvested from plants treated with NAA 100 ppm which was followed by (183.00 g) with urea 2 per cent and (170.67 g) with urea 1 per cent. It is also evident from the data that all the treatments produced significantly superior fruits than control. The treatment of 2,4-D 50 ppm recorded the fruit weight of (162.33 g) which was followed by (160.33 g) with NAA 75 ppm and (154.33g) with urea 1.5 per cent respectively. The treatments were further followed by 2, 4-D 30, 50 and 40 ppm with (152.33g), (149.00 g) and (146.66 g) fruit 100 weight respectively. All the treatments significantly increased the fruit weight as compared to control which generated (142.66 g) respectively. Increase in fruit weight might be attributed to the exogenous supply of NAA which might have helped in strengthening of middle lamella and consequently cell wall and might have increased the mobilization of food materials and minerals from other parts of the plant towards developing fruits that are extremely active metabolic sink which, in turn could have increased the fruit weight ( It is evident from the data that all the treatments significantly affected the TSS. Maximum TSS (11.05%) was recorded in 2, 4-D 50 ppm and it was followed by 2, 4-D 40 ppm (10.76%) and NAA 100 ppm (10.05%) TSS respectively. All the treatments were statistically at par with each other. The treatment of 2, 4-D 30 ppm recorded the TSS of (9.84%) which was followed by NAA 75 ppm (9.76%), and NAA 50 ppm (9.69%). These treatments were further followed by urea 1 per cent (9.51%), urea 1.5 per cent (9.52%) and urea 2 per cent (9.5%) respectively. TSS content of the fruits under control was the least amounting to (9.18%). Rajput et al (2015) reported that the TSS was increased due to its action on converting complex substances into simple ones, which enhanced the metabolic activity in fruits. The increase might be due to an increase in the mobilization of carbohydrates from the source of sink (fruits) by auxins. This might be attributed to the fact that NAA might have increased amylase activity and thus there was quick metabolic transformation of starch into soluble sugars and early ripening in response to growth substances lead to an increase in TSS. The results of the present study are in agreement with the findings of Agnihotri et al (2013) in guava. Similar results were also obtained by Dubey et al (2002).
It is clearly indicated from the data that the effect of NAA, 2,4-D and urea registered significant effects on titratable acidity. Acidity of fruits was reduced by the application of all the chemicals, however maximum reduction was noted with the foliar spray of 100 ppm NAA. The treatment of 2,4-D 50 ppm recorded the acidity of 0.33 per cent and it showed decrease in acidity with the increased concentration. The fruits under control registered the maximum acidity of 0.39 per cent. The lower acidity might be due to an early ripening of fruits caused by the treatment, where acid might have been used during respiration or fastly converted into sugars and their derivatives by reactions involving reverse glycolytic pathways or might have been used in respiration or both ( The data on effect of foliar application of NAA 2,4-D and urea on total sugars of fruits in guava cv. Allahabad Safeda depicted that significantly higher total sugars (10.46%) were analysed from the fruits treated with 2,4-D 50 ppm followed by 2,4-D 40 ppm with (10.31%) and NAA 100 ppm with (10.04%) total sugars. Treatment of 2,4-D 30 ppm registered (9.84%) total sugars followed by NAA 75 ppm with (9.64%) and NAA 50 ppm with (9.43%) respectively. Control registered the lowest (8.64%)total sugars. The increase in total sugars might be due to the fact 101 that growth regulators being helpful in the process of photosynthesis led to the accumulation of oligosaccharides and polysaccharides in higher amount. Besides this, they also regulates the enzymatic activity and the enzymes quickly metabolized the starch into soluble sugars and early ripening in response to growth substances. Data regarding effect of foliar application of NAA, 2,4-D and urea on reducing sugars of fruits of guava cv. Allahabad Safeda are presented in Table 4.16 and Figure 4.15. From the perusal of data it is clear that NAA, 2,4-D and urea exerted significant influence on the reducing sugars depicting the highest percentage of (4.98%) recorded in the fruits treated with 2,4-D 50 ppm followed by 2,4-D 40 ppm with (4.91%) and NAA 100 ppm with (4.87%) reducing sugars respectively. These treatments are further followed by urea 1.5 per cent with (4.13%), urea 2 per cent with (4.05%) and urea 1 per cent with (3.97%) reducing sugars respectively. Minimum reducing sugars of (3.82%) were recorded in the fruits under control. This might be due to the quick metabolic transformation of starch into soluble sugars. These results are in collaboration with the findings of Agnihotri et al (2013).
The data on effect of foliar application of NAA, 2,4-D and urea on reducing sugars of fruits in guava cv. Allahabad Safeda presented in Table 4.17 and Figure 4.16 depicted that significantly higher non reducing sugars (5.48%) were analysed from the fruits treated with 2,4-D 50 ppm followed by 2,4-D 40 ppm with (5.4%) and 2, 4-D 30 ppm with (5.19%) reducing sugars respectively. Treatment of NAA 100 ppm registered (5.17%) non-reducing sugars followed by urea 1.5 per cent with (5.05%) and NAA 75 ppm with (5.03%) non-reducing sugars. These treatments were further followed by urea 1 per cent with (4.99%), NAA 50 ppm with (4.92%) and urea 2 per cent with (4.86%) non reducing sugars respectively. Control registered the lowest non-reducing sugars percentage that is (4.82%).The better sugar content might be obtained by the synergetic effect of plant growth regulators. The research work of Agnihotri et al (2013) is also in line with the present studies.
The data pertaining to the ascorbic acid content clearly indicated that the different concentrations of NAA, 2, 4-D and urea exerted a significant influence on vitamin C with the highest (260.33mg/100g) content obtained from the plants treated with urea 2 per cent followed by urea 1.5 per cent and 2,4-D 40 ppm with (249.86mg/100g) and (248.93mg/100g). 2, 4-D 50 ppm registered vitamin C content (248.86mg/100g) followed by (247.03mg/100g) with 2, 4-D 30 ppm and (241.96mg/100g) with urea 1 per cent respectively. Minimum range of ascorbic acid (228.36mg/100g) was obtained under controlled conditions. These results are in agreement with the findings of Agnihotri et al (2013). This might be attributed to the fact that quick metabolic transformation of starch into soluble sugars and early ripening in response to growth regulators resulted in the good ascorbic acid content. The increase in ascorbic acid content might have resulted owing to biosynthesis of ascorbic acid from sugar or inhibition of oxidative enzymes or both due to favourable metabolic activity involving certain enzymes and metabolic ions under the influence of plant growth regulators and micro-nutrients (Rajput et al 2016). An increase in ascorbic acid content might be due to perpetual synthesis of glucose-6-phosphate throughout the growth and development of fruits which is thought to be the precursor of vitamin C. The research findings of Bariana and Dhaliwal (2002) also advocated the same in guava fruits cv. Sardar. The earlier findings of Singh et al (2002) and Sharma et al (2011) in guava are also in consonance with the present results.

Conclusion:-
It is concluded from the present study that 2,4-D 50 ppm proved to be the most effective treatment in enhancing the fruit yield and improving the fruit quality as compared to other treatments of NAA and urea.