Research Article, Vegetos Vol: 29 Issue: 1
Impact of Different Pruning Severity and Nutrient Management on Growth and Yield of Lemon cv. Assam Lemon (Citrus limon Burm.)
| Ghosh A1*, Dey K1, Bhowmick N1, Medda PS2 and Ghosh SK1 | |
| 1Department of Pomology and Post Harvest Technology, Uttar BangaKrishi Viswavidyalaya, West Bengal, India | |
| 2Department of Plantation Crops and Processing, Uttar BangaKrishi Viswavidyalaya, Pundibari, Cooch Behar, West Bengal, India | |
| Corresponding author : Ghosh A
Department of Fruits and Orchard management, Mohanpur, Nadia-741252, West Bengal, India Tel: 8967228963 E-mail: ghoshranasonai@gmail.com |
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| Received: February 22, 2016 Accepted: April 13, 2016 Published: April 20,2016 | |
| Citation: Ghosh A, Dey K, Bhowmick N, Medda PS, Ghosh SK (2016) Impact of Different Pruning Severity and Nutrient Management on Growth and Yield of Lemon cv. Assam Lemon (Citrus limon Burm.). Vegetos 29:1. doi: 10.5958/2229-4473.2016.00007.0 |
Abstract
Impact of Different Pruning Severity and Nutrient Management on Growth and Yield of Lemon cv. Assam Lemon (Citrus limon Burm.)
Like many other citrus species, the lemon (Citrus limon Burm.) presents a number of diverse forms slightly varying from each other. Pruning is one of the important approaches for the canopy management of citrus. The result of pruning on growth parameters have been reported by various workers. It is also a highly nutrient responsive perennial fruit crop and requires adequate nutrition for proper growth and yield of the plants. A field experiment was laid out in two factorial Randomized Block Design with four levels of pruning, seven levels of nutrient, consisting .recommended dose of fertilizers (RDF) and different combinations of organic manure (Vermicompost), inorganic fertilizer, bio-fertilizer (Azotobacter),mycorrhiza (VAM) and their interaction during 2013 to 2015.The investigation revealed that all the vegetative parameters viz. trunk girth (32.74cm, 33.26cm and 33.13cm) and its percentage increase (1.25%, 2.88% and 4.56%), canopy volume (85.22 m3 , 100.03 m3 and 125.84 m3 ) and its percentage increase (31.66%, 56.21% and 114.24%), number of laterals per primary shoot (9.53, 11.87 and 10.80) and its percentage increase (31.65%, 63.64% and 98.25%) and leaf chlorophyll content (1.45%, 1.94% and 2.56%) and its percentage increase (48.61%, 98.41% and 172.80%) was recorded best in highest level of pruning with 75% RDF + Vermicompost + Azotobacter + Vesicular Arbuscular Mycorrhiza at 6th, 12th and 18th month after pruning. Among the three season of cropping Ambebahar recorded the best result in respect to yield (total number of fruits/plant) followed by Mrig and Hasthbahar. .
Keywords: Assam lemon; Growth and yield; Nutrient management; Pruning
Keywords |
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| Assam lemon; Growth and yield; Nutrient management; Pruning | |
Introduction |
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| Citrus (Citrussp.), often regarded as ‘queen of fruits’ [1], are well known as one of the world’s major fruit crops that are produced in many countries with tropical and sub-tropical climate. It belongs to the family Rutaceae which consisting of 140 genera and 1300 species. It accounts for 3.7% (255.2 Thousand ha) of total area under fruit and 3.1% (2523.5 Thousand MT) of total fruit production with a productivity of 9.9 MT/ha. In West Bengal, the major lemon belts are Cooch Behar, Jalpaiguri, North and South 24 parganas and West and East Midnapur [2]. The most distinctive characteristics of the lemon fruit are oval to elliptical in shape with highly fragrant rind and have high acidity levels. Assam Lemon is one of the important dwarf cultivars of lemon, suitable for high density planting, extensively grown in the north-eastern parts of India [3]. In northern parts of West Bengal, it is early bearing with three fruiting season, viz. April- May, August-September and November-December. The earlier vegetative flushes of the previous season growth generally are more productive [4]. So pruning is very much essential to manipulate various aspects of vegetative and fruiting. Impact of Pruning and Nutrient Management on Growth and Yield of Lemon | |
| The cultural practice of pruning of stems increases vegetative and floral responses. By modifying the architecture of the aerial parts, shoot pruning profoundly affects tree growth and photosynthesis. Accelerated growth of shoots is generally observed after pruning and, depending on growth conditions, equilibrium between shoots and roots can be reached [5]. As lemon plants bears three times in an year, proper manuring and fertilization has to be resorted for obtaining highest yields and quality production which depends upon healthy and sturdy tree growth [6]. Furthermore, beside application of soul chemical fertilizers in traditional way, combine application of organic, inorganic and bio-fertilizers need to resort for avoiding the deleterious effect of chemical fertilizers and as well as improves physical properties of soil by increasing nutrient and water holding capacity, total pore space, aggregate stability, erosion resistance and temperature insulation. However, a little information is available about the response of lemon against pruning and nutrient management for this area. Keeping in view the present investigation was conducted to study the impact of pruning intensity and nutrient management in growth and yield of lemon cv. Assam lemon. | |
Materials and Methods |
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| Experimental Site | |
| The present investigation was carried out during 2013 and 2015 on 7 years old lemon cv. Assam lemon plants planted at 3m × 3m spacing at Instructional farm of Uttar BangaKrishi Viswavidyalaya, Pundibari, Cooch Behar, West Bengal, which was situated at 26019’86’’ N latitude and 89023’53” E longitude with an altitude of 43 meters above mean sea level. | |
| Treatments and design | |
| There were 4 levels of pruning, namely P0- No pruning (Control), P1- 25 cm pruning from the terminal portion of the shoot, P2- 50 cm pruning from the terminal portion of the shoot, P3- 75 cm pruning from the terminal portion of the shoot and 7 treatments of nutrient management viz. N1- 100% Recommended Dose of Fertilizer (N@210g/ plant-P@140g/plant-K@210g/plant), N2- Vermicompost (20 kg/ plant) + Azotobacter (18 g/plant) + Vesicular Arbuscular Mycorrhiza (150 g/plant), N3- Vermicompost, N4- 75% RDF + Vermicompost + Azotobacter + Vesicular Arbuscular Mycorrhiza, N5- 75% RDF + Vermicompost, N6- 50% RDF+ Vermicompost + Azotobacter + Vesicular Arbuscular Mycorrhiza and N7- 50% RDF + Vermicompost were applied alone and in combination with different levels of the pruning. The experiment was laid out in two factorial asymmetrical randomized block design (RBD) and 28 treatment combination (4 levels of pruning and 7 levels of nutrient) with 3 replications and 6 plants were kept in each treatment. All levels of pruning were done on 21st November, 2013, after harvesting of Mrigbahar. Nitrogenous fertilizer was applied in two split doses. Firstly, half dose of nitrogen and full dose of phosphorus, potassium and vermicompost were applied in February, 2014 and rest half of nitrogen was applied in April, 2014. Azotobacter and Vesicular Arbuscular Mycorrhiza were applied in December, 2013, after harvesting of Mrigbahar. | |
| Observation recorded | |
| All the vegetative parameters were recorded at initial stage and after that at 6 month interval after pruning. Height of the plant (m) was measured with the help of measuring tape and stick from the ground to top of the plant. Spread of the plant (m) was recorded at maximum width of the crown with the help of a measuring tape in both North- South and East-West direction at right angles. Plant girth (cm) was measured with the help of measuring tape at the maximum diameter of the trunk above the ground level. Canopy volume (m3) of a plant was measured by using height and spread of this particular plant. The formula is: canopy volume = 4/3 π a2 b, where a = ½ of plant height and b = average of east - west and north - south spread [7]. Percentage increase in canopy volume was measured by: [(Final volume – Initial volume) / Initial volume] × 100. For number of laterals five primary branches were randomly tagged in each of six selected plants and newly formed laterals arisen from those selected primary branch were counted. Percentage increase in number of laterals per primary shoot was measured by: [(Final number of laterals – Initial number of laterals) / Initial number of laterals] × 100. Total Leaf chlorophyll (mg total chlorophyll/g tissue) was extracted by homogenizing of 1 g fresh leaves in 10 ml of 80% acetone. After filtering, extract fill up to 10 ml in volume, the chlorophyll content was determined via an UV-Vis spectrophotometer (Perkins Elmar) from the acetone extract at 645 nm and 663 nm, as described by Witham et al. [8]. Total chlorophyll content as mg in 1 gram of plant tissue was calculated as: mg total chlorophyll/g tissue = [20.2 (D645) + 8.02 (D663)]. (V/1000 weight), where D = Absorbance values. Percentage increase in leaf chlorophyll content was measured by: [(Final leaf chlorophyll content – Initial leaf chlorophyll content) / Initial leaf chlorophyll content] × 100. The number of fruits harvested under each treatment was recorded from six randomly selected trees and the average number of fruits harvested from six trees was calculated for each treatment likewise. | |
| Statistical Analysis | |
| Analysis of variance (one way classified data) for each parameter was performed using ProcGlm of Statistical Analysis System (SAS) software (version 9.3). Mean separation for different treatment under different parameter were performed using Least Significant Different (LSD) test (P ≤ 0.05). Normality of residuals under the assuming of ANOVA was tested using Kolmogrov-Smirnov, Shapiro-Wilk, Cramer-Von Mises and Anderson Darling procedure using Proc- Univariate procedure of SAS (version 9.3). Data transformation was done followed by the method of Gomez and Gomez [9]. | |
Results and Discussion |
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| Plant height (m) | |
| The data pertaining to plant height has been presented in Table 1. Observation revealed that the plant height was increased in all the treatments up to the end of experiment. Significant variation with respect to plant height was observed among several pruning treatments except in percent increase at 12th month after pruning, where plant height is statistically at par under all pruning level. Maximum plant height (3.56 m, 3.78 m and 4.29 m) and its percentage increase (6.18%, 12.82% and 28.08%) was recorded in highest level of pruning P3 (75 cm pruning from the terminal portion of the shoot) at 6th, 12th and 18th month after pruning followed by medium level P2 (50 cm pruning from the terminal portion of the shoot) of pruning (3.52 m, 3.74 m and 4.24 m; 5.76%, 12.18% and 27.61%) after 6th, 12th and 18th months after pruning. The lowest plant height and its percentage increase was observed in (P0) unpruned plants (3.42 m, 3.61 m and 3.91 m; 4.36%, 10.64% and 20.22%) at 6th, 12th and 18th month after pruning. The effect of different nutrient treatments was significant in plant height except it’s percent increase at 6th, 12th and 18th month after pruning, where the data’s were statistically at par. It cleared that treatments have no effect on percentage increase in height. The highest plant height (3.58 m, 3.65 m and 4.06 m) and its percentage increase (6.18%, 12.82% and 28.08%) was recorded in N4 (75% RDF+ Vermicompost + Azotobacter + Vesicular Arbuscular Mycorrhiza) at 6th, 12th and 18th month after pruning followed by N6 (50% RDF+ Vermicompost + Azotobacter + Vesicular Arbuscular Mycorrhiza) (3.44 m, 3.65 m and 4.04 m; 4.55%, 11.05% and 22.93%). Lowest plant height (3.27 m, 3.45 m and 3.76 m) and its percentage increase (3.36%, 8.94% and 18.57%) was observed in N3 (Vermicompost) at 6th, 12th and 18th month after pruning. These results are in line with that of Nath and Baruah [10] who reported that highest level of pruning gave the best result as it caused better movement of air and light in to the inner part and thereby resulted in greater photosynthesis. This increased photosynthesis activity of the plants leads to higher accumulation of the photosynthates, which were utilized by developing shoots, leading to increase in plant height. | |
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Table 1: Effect of pruning and nutrient management on plant height of lemon cv. Assam lemon. |
| Trunk girth (cm) | |
| Observation revealed that the trunk girth was significantly increased in all the treatments up to the end of experiment (Table 2). However, the data’s were statistically at par under P1 and P2 level at 6th, 12th and 18th month after pruning. Maximum trunk girth (31.06 cm, 31.43 cm and 31.60 cm) and its percentage increase (0.94%, 2.18% and 3.92%) was recorded in highest level of pruning P3 (75 cm pruning from the terminal portion of the shoot) at 6th, 12th and 18th month after pruning followed by medium level P2 (50 cm pruning from the terminal portion of the shoot) of pruning (28.71 cm, 29.01 cm and 29.24 cm; 0.70%, 1.73% and 2.92%). The lowest trunk girth and its percentage increase was observed in (P0) unpruned plants (25.48 cm, 25.67 cm and 27.09 m; 0.58%, 1.34% and 2.45%) after 6th, 12th and 18th months after pruning. Several nutrient treatments have significant effect on percentage increase of trunk girth at 12th and 18th months after pruning. The highest trunk girth (27.10 cm, 27.34 cm and 27.67 cm) and its percentage increase (0.63%, 1.51% and 2.51%) was recorded in N4 (75% RDF + Vermicompost + Azotobacter + Vesicular Arbuscular Mycorrhiza) at 6th, 12th and 18th month after pruning followed by N6 (50% RDF + Vermicompost + Azotobacter + Vesicular Arbuscular Mycorrhiza) (26.90 cm, 27.12 cm and 27.50 cm; 0.62%, 1.44% and 2.49%). Lowest trunk girth (24.47 cm, 24.65 cm and 25.05 m) and its percentage increase (0.56%, 1.31% and 2.12%) was observed in N3 (Vermicompost) at 6th, 12th and 18th month after pruning. Combination of organic, bio-fertilizer with highest amount of inorganic fertilizers gave the best result as biofertilizer increased the availability of nutrients by increasing the absorption and mobilization of nutrients which was supplied by organic and inorganic fertilizers resulted better food reserve and enhanced trunk girth [11,12]. | |
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Table 2: Effect of pruning and nutrient management on trunk girth of lemon cv. Assam lemon. |
| Plant spread (N-S) | |
| The data on plant spread (N-S) presented in Table 3 indicated the significant variation under different pruning levels. However the datas were statistically at par under P1 and P2 level at initial, 6th month and 12th month, and under P2 and P3 level at 18th month after pruning Results indicated that the Plant spread (N-S) was increased in all the treatments up to the end of experiment. Maximum plant height (5.03 m, 5.29 m and 5.95 m) and its percentage increase (6.52%, 13.04% and 40.23%) was recorded in highest level of pruning P3 (75 cm pruning from the terminal portion of the shoot) at 6th, 12th and 18th month after pruning followed by medium level P2 (50 cm pruning from the terminal portion of the shoot) of pruning (4.74 m, 5.01 m and 5.72 m; 5.61%, 11.37% and 37.26%) after 6th, 12th and 18th months after pruning. The lowest plant spread (N-S) and its percentage increase was observed in (P0) unpruned plants (3.99 m, 4.17 m and 4.88 m; 4.85%, 10.03% and 28.07%) at 6th, 12th and 18th month after pruning. Plant spread (N-S) were statistically at par at initial, 12th month (only percentage increase) and 18th month (only spread) after pruning. The highest plant spread (N-S) (5.02 m, 4.43 m and 5.10 m) and its percentage increase (4.98%, 10.09% and 28.33%) was recorded in N4 (75% RDF + Vermicompost + Azotobacter + Vesicular Arbuscular Mycorrhiza) at 6th, 12th and 18th month after pruning followed by N6 (50% RDF+ Vermicompost + Impact of Pruning and Nutrient Management on Growth and Yield of Lemon: Azotobacter + Vesicular Arbuscular Mycorrhiza) (4.14 m, 4.34 m and 5.09 m; 4.93%, 10.05% and 28.27%). Lowest plant spread (NS) (3.49 m, 3.72 m and 4.48 m) and its percentage increase (3.09%, 9.66% and 28.03%) was observed in N3 (Vermicompost) at 6th, 12th and 18th month after pruning. Combination of organic, bio-fertilizer with highest amount of inorganic fertilizers gave the best result as biofertilizer increased the availability of nutrients by increasing the absorption and mobilization of nutrients which was supplied by organic and inorganic fertilizers resulted better food reserve which enhanced plant spread [11,12]. | |
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Table 3: Effect of pruning and nutrient management on plant spread (E-W) of lemon cv. Assam Lemon. |
| Plant spread (E-W) | |
| Experiment results revealed that the plant spread (E-W) was increased significantly in all the treatments up to the end of experiment (Table 4). Results showed that data’s were statistically at par under P1 and P2 level at initial, 6th month and 12th month except under P0 and P1 at 18th month after pruning (only percentage increase). Maximum plant spread (E-W) (5.68m, 6.48m and 6.31 m) and its percentage increase (14.96%, 31.20% and 37.66%) was recorded in highest level of pruning P3 (75 cm pruning from the terminal portion of the shoot) at 6th, 12th and 18th month after pruning followed by medium level P2 (50 cm pruning from the terminal portion of the shoot) of pruning (5.13 m, 5.81 m and 5.99 m; 14.15%, 29.15% and 33.90%). The lowest plant spread (E-W) and its percentage increase was observed in (P0) unpruned plants (4.29 m, 4.83 cm and 5.25 m; 12.33%, 26.53% and 27.73%) after 6th, 12th and 18th months after pruning. Different nutrient treatments had significant effect on plant spread (E-W) except in percentage increase at 12th and 18th month after pruning. The highest plant spread (E-W) (4.65m, 5.19m and 5.60m) and its percentage increase (13.40%, 27.67% and 30.04%) was recorded in N4 (75% RDF+ Vermicompost + Azotobacter + Vesicular Arbuscular Mycorrhiza) at 6th, 12th and 18th month after pruning followed by N6 (50% RDF+ Vermicompost + Azotobacter + Vesicular Arbuscular Mycorrhiza) (4.52 m, 5.09 m and 5.81 m; 13.30%, 27.55% and 29.28%). Lowest plant spread (E-W) (4.28 m, 4.80 m and 5.12 m) and its percentage increase (11.86%, 26.23% and 26.32%) was observed in N3 (Vermicompost) at 6th, 12th and 18th month after pruning. Observation revealed that all the data’s were statistically at par under different treatment combination. These results are in agreement with the findings recorded by Nath and Baruah [10], Boughalleb et al. [11], Kundu et al. [12] and Lal and Dayal [13]. | |
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Table 4: Effect of pruning and nutrient management on plant spread (N-S) of lemon cv. Assam Lemon. |
| Canopy volume (m3) | |
| The data pertaining to canopy volume has been presented in Table 5, were significantly different under different pruning level. However the datas of percentage increase in canopy volume were statistically at par at 6th and 12th month after pruning under P0 and P1. Observation revealed that the plant height was increased in all the treatments up to the end of experiment. Maximum canopy volume (70.94 m3, 82.54 m3 and 112.13 m3) and its percentage increase (25.43%, 47.52% and 102.29%) was recorded in highest level of pruning P3 (75 cm pruning from the terminal portion of the shoot) at 6th, 12th and 18th month after pruning followed by medium level P2 (50 cm pruning from the terminal portion of the shoot) of pruning (63.97 m3, 75.98 m3 and 104.10 m3; 22.76%, 46.45% and 99.90%) after 6th, 12th and 18th months after pruning. The lowest canopy volume and its percentage increase was observed in (P0) unpruned plants (51.50 m3, 60.49 m3 and 77.15 m3; 18.31%, 40.90% and 89.86%) at 6th, 12th and 18th month after pruning. Observation showed that nutrient treatments were resulted in significant variation in the datas except percentage increase at 12th month after pruning. The highest canopy volume (64.77 m3, 65.91 m3 and 87.93 m3) and its percentage increase (42.16%, 44.98% and 93.06%) was recorded in N4 (75% RDF + Vermicompost + Azotobacter + Vesicular ArbuscularMycorrhiza) at 6th, 12th and 18th month after pruning followed by N6 (50% RDF+ Vermicompost + Azotobacter + Vesicular Arbuscular Mycorrhiza) (53.62 m3, 65.18 m3 and 85.71 m3; 19.26%, 44.90% and 92.73%). However, canopy volume (43.48 m3, 52.67 m3 and 67.60 m3) and its Impact of Pruning and Nutrient Management on Growth and Yield of Lemon | |
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Table 5: Effect of pruning and nutrient management on canopy volume of lemon cv. Assam Lemon. |
| percentage increase were minimum (15.16%, 39.25% and 78.68%) in N3 (Vermicompost) at 6th, 12th and 18th month after pruning. These results are in line with that of Nath and Baruah [11] who reported that highest level of pruning gave the best result as it caused better movement of air and light in to the inner part and thereby resulted in greater photosynthesis. This increased photosynthesis activity of the plants leads to higher accumulation of the photosynthetic, which were utilized by developing shoots, leading to increase in plant vigour. | |
| Number of laterals per primary shoot | |
| Observations revealed that the number of laterals per primary shoot was significantly increased in all the treatments up to the end of experiment (Table 6). Maximum number of laterals per primary shoot (7.70, 9.33 and 10.17) and its percentage increase (25.43%, 54.54% and 80.13%) was recorded in highest level of pruning P3 (75 cm pruning from the terminal portion of the shoot) at 6th, 12th and 18th month after pruning followed by medium level P2 (50 cm pruning from the terminal portion of the shoot) of pruning (6.71, 8.09 and 9.60; 20.85%, 44.26% and 74.97%). The lowest number of laterals per primary shoot and its percentage increase was observed in (P0) unpruned plants (4.50, 6.13 and 7.83; 16.56%, 35.03% and 65.17%) after 6th, 12th and 18th months after pruning. The significantly highest number of laterals per primary shoot (5.96, 6.78 and 8.50) and its percentage increase (18.27%, 38.25% and 71.12%) was recorded in N4 (75% RDF + Vermicompost + Azotobacter + Vesicular Arbuscular Mycorrhiza) at 6th, 12th and 18th month after pruning followed by N6 (50% RDF + Vermicompost + Azotobacter + Vesicular Arbuscular Mycorrhiza) (5.86, 6.99 and 8.47; 17.29%, 38.06% and 70.84%). Lowest number of laterals per primary shoot (5.03, 5.37 and 7.40) and its percentage increase (14.78%, 30.49% and 52.45%) was observed in N3 (Vermicompost) at 6th, 12th and 18th month after pruning. These results are in agreement with Nath and Baruah [10] and Guimond et al. [14] who reported that higher level of pruning increases number of laterals in lemon and bing cherry which might be due to simply removal of hormonal influence (and resource sink) of the apical meristem plays a large role in shifting basal meristem determination to ward new shoots and floral initiation. Similar results also found by Kovaleski et al. [15] in highbush blue berry varieties cv. ‘Emerald’ and ‘Jewel’. | |
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Table 6: Effect of pruning and nutrient management on number of laterals/ primary shoot of lemon cv. Assam Lemon. |
| Total leaf chlorophyll content (mg/g fresh weight) | |
| Recorded observations on leaf chlorophyll content have been presented in Table 7. It was significantly increased in all the pruning treatments up to the end of experiment. Maximum leaf chlorophyll content (1.39 mg/g fresh weight, 1.85 mg/g fresh weight and 2.46 mg/g fresh weight) and its percentage increase (47.65%, 96.56% and 163.63%) were recorded in highest level of pruning P3 (75 cm pruning from the terminal portion of the shoot) at 6th, 12th and 18th month after pruning followed by medium level P2 (50 cm pruning from the terminal portion of the shoot) of pruning (1.34 mg/g fresh weight, 1.78 mg/g fresh weight and 2.38 mg/g fresh weight; 46.82%, 95.14% and 161.90%). The lowest leaf chlorophyll content (1.21 mg/g fresh weight, 1.60 mg/g fresh weight and 2.29 mg/g fresh weight) and its percentage increase (43.66 %, 90.45 % and 156.61%) were observed in (P0) unpruned plants after 6th, 12th and 18th months after pruning. Observation revealed that different nutrient treatments have no effect on leaf chlorophyll content. The highest leaf chlorophyll content (1.29 mg/g fresh weight, 1.71 mg/g fresh weight and 2.33 mg/g fresh weight) and its percentage increase (45.06 %, 92.58 % and 160.01%) was recorded in N4 (75% RDF + Vermicompost + Azotobacter + Vesicular Arbuscular Mycorrhiza) at 6th, 12th and 18th month after pruning followed by N6 (50% RDF+ Vermicompost + Azotobacter + Vesicular ArbuscularMycorrhiza) (1.28 mg/g fresh weight, 1.70 mg/g fresh weight and 2.33 mg/g fresh weight; 44.94%, 92.13% and 158.70%). Lowest leaf chlorophyll content (1.23 mg/g fresh weight, 1.62 mg/g fresh weight and 2.27 mg/g fresh Impact of Pruning and Nutrient Management on Growth and Yield of Lemon weight) and its percentage increase (42.71%, 87.71% and 152.59%) was observed in N3 (Vermicompost) at 6th, 12th and 18th month after pruning. It might be due to the fact that Azotobacter stimulates nutrient uptake especially nitrogen which has role in the assimilation of numerous amino acids that are subsequently incorporated in proteins and nucleic acid, which provides framework for chloroplast, mitochondria and other structures in which the most of the biochemical reactions occurs and resulted in to increase in chlorophyll content of leaves, photosynthetic efficiency, translocation of metabolites from the source to sink [16]. | |
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Table 7: Effect of pruning and nutrient management on leaf chlorophyll content of lemon cv. Assam Lemon |
| Total number of harvested fruits | |
| Significant variation with respect of number of harvested fruits was observed in three seasons under different pruning and nutrient treatments. The data pertaining to total number of harvested fruits revealed that maximum number of harvested fruits was recorded (Table 8) in P1 (25 cm pruning from the terminal portion of the shoot) at Ambe, Mrig and Hasthbahar (219, 129 and 39) followed by P2 (50 cm pruning from the terminal portion of the shoot) (146, 88 and 27) at Ambe, Mrig and Hasthbahar. However, the lowest number of harvested fruits was observed in (P0) unpruned plants (103, 46 and 12) at Ambe, Mrig and Hasthbahar respectively. The significantly highest number of harvested fruits was recorded (114, 60 and 17) in N4 (75% RDF + Vermicompost + Azotobacter + Vesicular Arbuscular Mycorrhiza) at Ambe, Mrig and Hasthbahar followed by N6 (50% RDF+ Vermicompost + Azotobacter + Vesicular Arbuscular Mycorrhiza) (112, 54 and 16). Lowest number of harvested fruits (80, 36 and 8) was observed in N3 (Vermicompost) at Ambe, Mrig and Hasthbahar respectively. Increased number of harvested fruits might be due to NPK in association of biofertilizer, VAM and Vermicompost at desired amount, enhanced leaf chlorophyll content resulting in accumulation of more photosynthates, ultimately resulted in more number of fruits at harvest [11,12]. Singh et al. [17] also found the same results in papaya cv. Pusa Dwarf. | |
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Table 8: Effect of pruning and nutrient management on yield (Total number of Harvested fruits) of lemon cv. Assam Lemon. |
Conclusions |
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| From the foregoing discussion, it can be concluded that efficient management of organic, inorganic and biofertilizers rather than sole organic or inorganic is essential to improve vigourand yield of lemon plants. Besides this, prunings have a significant effect in increasing the flower bearing shoots. Hence, light pruning (25 cm pruning from the terminal portion of the shoot) along with integrated use of fertilizers viz. 75% RDF + Vermicompost + Azotobacter + Vesicular ArbuscularMycorrhiza proved as best in terms of total fruits per plants in lemon cv. Assam lemon as compared to plants under control. | |
References |
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