Effect of GA3 and urea spray on flowering fruit retention and fruit quality of mango cv. langra.
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Date
2014
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JNKVV
Abstract
ABSTRACT
Langra mango is cultivated on a large scale in eastern Madhya Pradesh especially in Rewa region. It is prone to heavy fruit drop as seen in the other commercial varieties also Investigations have shown that plant regulating substances play an important role in terms of quantity as well as quality improvement in mango urea is an important nutrient for plant growth and development. Pre-harvest spray of GA3 advances the fruit maturity and ripening by several weeks and significantly improves fruit quality and reduce spoilage losses during storage. Therefore looking to these aspects, the present investigation entitled “Effect of GA3 and urea spray on flowering, fruit retention and fruit quality of mango cv Langra, was carried out during the year 2012-13 at the Fruit Research Station, Kuthulia, College of Agriculture, Rewa (M.P.). The physical and chemical qualities of the treated fruits were determined in the laboratory of the department of soil science of this campus.
The treatments comprised three sprays of GA3 (0, 15 and 30 ppm) and three spray of urea (0, 3 and 6%). Thus nine treatment combinations were tested in a randomised of these treatment combinations, thus the total number of mango plants under study were twenty seven. These were spaced at 10m x 10 m distance. The periodical observations related to flowering, fruit settings productivity parameters and physico- chemical parameters properties of mango fruits were taken as per recorded and standard procedures. The data so obtained were statistically computed before their presentation.
The important results obtained during the present investigation are summarized as below.
Phenological parameters
In the present research, spraying of GA3 at 30 ppm along with 6% urea spray proved the best where the date of first appearance of flowering was earliest on 18 January. Consequently the date of 50% flowering reached earliest on 18 February and full bloom of lowering on 8 March followed by GA3 (15ppm) and 3% urea spray.
Flowering behaviour
The number of male and hermaphrodite flowers did not change upto significant extent due to different concentrations of GA3 and urea spray on Langra mango. Accordingly the total (male + hermaphrodite) flowers at 30ppm GA3 were lower (715.33/panicle) as against higher (777.11/panicle) at 0 ppm GA3. The reverse situation was true in case of urea spray. The total flowers at 6% urea were higher (763.22/panicle) as against lower (718.66 flowers/panicle) at 0% urea spray.
Fruit settings/panicle
The different concentrations of GA3 as well as urea spray did not influence significantly the pea- size, marble size and mature size fruits/panicle. However slight changes observed where in GA3 at 15ppm spray and urea 6% spray performed better over the other respective concentrations. GA3 (15ppm) recorded non-significantly higher pea size fruits (6.88/panicle), marble size fruits (1.44/panicle) and mature size fruits only 0.67panicle. Similarly urea spray at 6% brought about higher fruit settings which were 6.10, 1.55 and 0.78/panicle, respectively.
Productivity parameters
Different concentrations of GA3 influenced the productivity parameters significantly. Spraying of GA3 at 15 and 30ppm increased equally the number of fruits (183.55/plant) as well as equally increased the fruit yield (46.95 to 47.05 q/ha), being significantly superior to without GA3 spray. Urea spray with 6% brought about significantly higher number of fruits (192.44/plant) over the lowest urea concentrations. Even 3% urea proved significantly superior to 0% urea spray (180.77 fruits/plant) as well as equally increased the yield (q/ha) with urea spray (6 and 3%) .
Physical parameters
The GA3 spray treatments influenced the length and width of mango fruits significantly but not the weight of fruits. Maximum length (10.33 cm) and width (6.13 cm) was recorded under 15 ppm GA3, being significantly superior to other treatments. The increasing levels of urea spray significantly increased all physical parameters. It is apparent that the combined input of GA3 and urea further encourage all these parameters synergistically. Their additive effect was eventual.
Among the physical parameters and the specific gravity was influenced significantly due to GA3 and urea spray as well as their interactions, but fibre content remained unchanged in the mango fruits. GA3 15ppm and urea 6% resulted in significantly higher specific gravity (1.01 to 1.02) over the remaining respective treatments. When both these chemicals applied together the specific gravity was further augmented upto 1.03.
The pulp, peel and stone percentages in mango fruits did not change upto significant extents due to GA3 levels, however peel and stone percentages deviated significantly in higher urea levels but the pulp percentage was not significant.
Physiological weight loss
Irrespective of the treatments, the physiological weight loss of mango fruits was found to increase by more than two to three fold with the increase in the storage period upto 12 days.
The physiological weight loss of mango fruits was influenced significantly due to GA3 and urea spray levels as well as their interactions during storage period upto 12 days.
The physiological weight loss was significantly reduced due to 15 ppm GA3 followed by 30ppm GA3 at every stage of observation during storage period. Similarly 6% urea spray also resulted in minimum weight loss upto 12 days period. Thus the overall picture indicate that both GA3 and urea spray proved highly beneficial in reducing the weight loss of mango fruits during storage period.
Spoilage percentage
The spoilage percentage of mango fruits enhanced by multi-fold with the increase in storage period from 4 to 12 days. Thus the total spoilage percentage in different treatments ranged from 42.78 to 73.33%.
The spoilage loss of mango fruits was significantly reduced due to 15 and 30ppm GA3 as well as 6% urea spray. At 12 days, the spoilage loss was minimum (42.78%) due to 15 ppm GA3 as against 73.3% under 0% GA3. Similarly, the spoilage loss minimum (49.44%) due to 6% urea spray as against 62.22% under 0% urea spray. Thus the overall picture indicate that the both GA3 as well as urea spray performed the best in reducing the fruit spoilage during storage period of mango fruits.
The storage life of mango fruits at room temperature enhanced upto significant extent nearly upto two days due to 15 and 30 ppm GA3 as well as 3 and 6% urea spray over control. This was eventual because of the fact that the urea chemical or GA3 growth regulator reduced the physiological weight loss as well as spoilage percentage upto significant extent which resulted in increased storage life of the mango fruits.
Organoleptic rating
This includes appearance sensory score colour flower, test and texture of mango fruits which was observed after treatment with GA3 and urea spray under different concentrations. Both the levels of GA3 15 and 30ppm and urea spray (3 and 6%) resulted in significantly maximum organoleptic rating over no applications. In case of 15 and 30ppm GA3 the highest organoliptic rating ranged from 7.33 to 7.72 and incase of urea spray (3 and 6%) the maximum rating ranged from 8.22 to 8.89. In case of colour and taste, these values comes under excellent score.
Chemical parameters
The total sugars, reducing and non-reducing did not change due to GA3 and urea spray treatments.
There were no any changes in the TSS and acidity of the mango fruits due to different concentrations of GA3. However, urea spray brought about significant changes in both these chemical parameters. Urea spray upto 6% recorded significantly higher TSS (22.350Brix) and significantly lowest acidity (0.26%). On the other hand, the reverse trend was obtained at 0% urea where TSS was significantly lowest (20.250Brix) and the acidity was significantly highest (0.30 %).
The significantly lowest acidity due to 6% urea spray was recorded in mango fruits during pre-storage conditions.
CONCLUSION
The findings allude that GA3 (15ppm) and urea spray (6%) have significant role in augmenting productivity and physico- chemical properties of mango fruits with minimum weight loss and spoilage of fruits.
SUGGESTIONS
The experiment may be continued further for two years or more so that final recommendations may be made for the mango growers of this region.