Influence of Pruning Methods on Growth and Fruiting of Naomi Mango Trees under New Valley Conditions

During the 2021 and 2022 seasons, this research was conducted in the Balat area of Afaq Farm, located in the New Valley Governorate. Evaluating the timing and location of pruning and its effect on the growth and fruiting of Naomi mango trees. The experiment was carried out in a completely randomized block design with seven treatments and using three replicates, with two trees for each treatment. The current results are as follows: Shoot length, leaf area, total chlorophyll, shoot length, fruit set, and fruit set were significantly increased due to above-or below-bud pruning in March, May, or August compared to unpruned trees (check treatment). Pruning in May or August is generally better than in March. In addition, pruning under the buds at any time is better than pruning above the buds. There were no significant differences in most of the studied traits between the use of pruning in the months of May and August. In addition, the use of no previous treatments increased productivity and improved fruit quality compared to unpruned trees. In general, pruning trees in May above or below the bud gave the highest values for these studied traits. All pruning operations led to a significant improvement in the chemical components of fruit juice in terms of higher values of total and reducing sugars and total soluble solids and a significant decrease in total acidity compared to the control treatment. The results obtained indicated a noticeable improvement in vegetative growth and fruiting characteristics because of pruning Naomi mango trees during the months of May and August, much less than buds


Introduction
Mango is a tropical and seasonal fruit that is generally available during the summer season in Egypt and the main harvest collection period is May to September.The mango (Mangifera indica L., Family Anacardiaceae) is known as the queen of fruit with an excellent exotic flavor.Global production of the fruits of mango amounted to about 50 million tons (FAO, 2020).In Egypt, among the fruit crops, mango is second, followed by citrus.The area under mango tree cultivation in the reclaimed land has increased particularly rapidly.It reached about 32, 10 acres, with 294, 10 acres of productive mango, while annual production totaled 76, 61 tons, according to statistics (M.A.L.R.2021).Mango is one of favorite fruits in New Valley Governorate.
Nevertheless, mango cultivation is still limited and large quantities of mango are imported from other governorates, although mango is one of the most successful fruit crops that can be grown in newly reclaimed desert land.However, this work could contribute to the provision of cultural information on mango cultivation in the New Valley Governorate.The Naomi tree is medium-sized and fairly erect.Young leaves are reddish-brown.The seed is monoembryonic.The flesh is fiber-free, yellow in color, and has a mild flavor.The fruits are medium in size, rectangular, oval in shape, and change color when ripe.Naomi is a midseason mango (Tomer et al., 1993).In mango, just before or during flowering the removal of the apical bud or inflorescence on terminal buds results in the development of auxiliary suppressive buds usually adjacent to the point of the cut.These buds usually develop as inflorescences, from the initiation of normal bud development especially if pruning is performed before or shortly after flowering (Issarakraisila et al., 1991).
Some mango varieties have been successfully grown that were previously introduced to Egypt and exhibited excellent fruit quality under various regional conditions such as Keitt, Kent, Heidi, Naomi and Tommy Atkins cultivars  2009), to motivate dormant vegetable buds, umbrella pruning is carried out so that buds grow a lot and easily create an umbrella.To prevent trees from being large through annual pruning, three trim strategies have been developed as part of the flowering management program, the regeneration of completely large trees that are no longer produced due to volume and height, and the reshaping of medium-sized trees to be smaller and more manageable sizes.Generally, the commercial production of mango trees starts from three to four years after cultivation with the enlargement of the aircraft and the continuation of the production of increasing returns until the shading of the adjacent trees is forced to grow up and away from the harvest.Because of the shading by the upper branches, the low branches that support the productive legs for the previous year decrease.It occurs on flowering stem stations and fruit production in mangoes.Therefore, with an increase in the size of the umbrella, the continuation of the competition for the available light and the production moves to the top.The branch cut for the mango leads to several buds in the next flow period.By declining in the bud, pruning aims to form an umbrella, the aim of pruning in trees is to reduce umbrella dimensions or make it more suitable for trim that has become crowded as part of the flowering management program.Depending on the original size of the trees, this type of pruning requires cutting branches, which countries range from 2 to 10 cm.To restore the umbrella within the final required dimensions, the depth of pruning should be at least one meter in the canopy.(Daven port, 2006).
Mango plants that are one trimming (flow) can stimulate directly spy buds in their separation, and the growth of the new buds (HIIDAYAT, 2005).For a number more than the buds produced through pruning, and for the formation of buds, there are many ready nodes.The principle of pruning is to stimulate the obstetric; the formation of vegetative buds and to increase the productivity of the mango factory, the branch is broader.(Kusumo, 1989).The growth of mango trees is evident in the branches of the station that stem through the outskirts of the scaffolding to the union of graft.To form a group of buds at every termination of a flow, each flow of vegetative growth must be characterized by a close to each other in long internal shapes.The growth record of these flows in the branches was described as intercalary units and buds and the leaves are collected at the end of each intercalary unit from STEM as intermittent menus (Davenport & Nunez-Elisea, 1997).
Therefore, from the current study the goal was to study the methods of pruning and their effects on the growth and fruiting of mango Naomi.

Materials and Methods
The current research was implemented during two seasons, 2021 and 2022 on the developing mango trees in the Balat area in the farm of Afaq, New Valley Governorate, Egypt.Where the soil is from the conjunctiva.Relative humidity data and monthly air temperatures during the two studied seasons, as the averages are in Table (1)  The pruning location is shown in Plate (1) according to Fadhilnor and Tengku Ab.Malik (2018).The trees were 6 years old and spaced 2x3 meters apart.The seven different treatments were as follows: 1-Unpruned trees control (T1).2-Prune in March above node (T2).3-Prune May above node (T3).4-Prune August above node (T4).5-Prune in March below node (T5).6-Prune in May below node (T6).7-Prune in August below node (T7).
Growth 'transactions are evaluated and the following transactions have been studied.

1-Vegetative growth and flowering criteria:
All vegetative and flowering growth criteria shoot length, leaf area and panicle were measured in the mid of July.Leaf area (cm 2 ): (Ahmed & Morsy, 1999) and Total chlorophyll was measured in leaves by using chlorophyll meter.

2-Yield parameters:
a-Fruit set: fruit set percentage was calculated by dividing number of fruit set at pea stage per panicle to number of hermaphrodite flowers per and expressed in percentage.b-Fruit weight and yield per tree: fruit were harvested and their weight (kg) recorded, then the yield / tree (kg) was recorded by multiplying the average fruit weight (kg) by total number of fruits per trees.c-Fruit diminution: were measured by Vernier Caliper (in cm).

Statistical analysis -:
The least significant difference (LSD) test was used at the 5% level to differentiate between means and a completely randomized design with three replications and a factorial was followed throughout the entire work according to Snedecor and Cochran (1990).

1-Vegetative and flowering traits:
Data represented in in Figure (1) and Table (2) declared the effect of pruning methods on total chlorophyll, leaf area and shoot length as well as panicle length and fruit set of Naomi mango trees during 2021 and 2022 seasons.From the data obtained, it is clear that the results during the two studied seasons followed the same trend.In a general show, the data in the Table and the following figure showed that pruning is in May or August, whatever, above or below buds significantly stimulated the shoot length, leaf area and total chlorophyll as well as panicle length and fruit set compared to prune in March or untreated ones (control).The maximum values of shoot length, leaf area and total chlorophyll as well as panicle length and fruit set were recorded on pruning in May below node (T6), followed by pruning in May above nodes (T3), respectively.On the other hand, the lowest values for growth and flowering parameters were obtained in untreated (control) trees (T1), followed by pruning in March above the node (T2 respectively.No significant differences were found in shoot length leaf area, and total chlorophyll due to pruning trees in May or August above or below nodes.In addition, no significant differences were found in panicle length, fruit set and fruit retention due to pruning trees in May above or below nodes were done.
Therefore, pruning trees in May or August above or below nodes significantly improves vegetative traits and total leaf surface area, which leads to a significant increase in flower formation and fruit set.The positive effects of this pruning certainly improve growth and flowering traits leading to increase the yield production.

2-Yield components and fruit characters:
The clear data in Table (3.4)affects pruning methods on No. fruit/tree, yield/tree and fruit weight as well as fruit diminution, percentage of pulp and peel of Naomi mangoes during 2021 and 2022 seasons.It appears that the results followed the same trend during the two seasons studied from the data obtained.In general, view pruning trees in May and August above or below the node.significantly increased the number of fruit per tree and yield/tree as well as fruit weight, fruit dimension and percentage of pulp and peel to untreated one (control).The highest yield components and fruit physical characters were recorded on the trees that pruned below the node in May (T6) followed by pruning above the node in May (T3) .The obtained highest values of fruit numbers / tree were (37.7 & 35.0 fruit), yield/tree (17.13 & 14.72 kg) and fruit weight (454.6 & 420.6) g as an av. of two seasons studied due to pruned trees in May below the node (T6) or pruned trees in May above the node (T3), respectively.Contrarily, these values on check tree were (25.0 fruit, 6.48 Kg & 260.7 g) respectively.Hence, the corresponding increment percentage for yield was (164.35 & 127.16%) and fruit weight was (74.38 & 61.33%) due to use (T6 and T3) over control (T1), respectively.The better fruit diminution registered on trees that pruning in May below the node (T6) or in May above the node (T3) (15.35&15.00cm) in fruit length and (8.65&8.2) as an av. of studied seasons, respectively, whereas the least fruit diminution was recorded on trees that unpruned (control, T1) (10.9 & 5.85 cm), respectively.Then, the corresponding increment percentage of fruit diminution due to such treatments over control (T1) was (40.73 & 37.61%) and (47.86 & 40.17) respectively.
Moreover, the obtained highest values of percentage of pulp were (86.27 & 85.85 %) due to prune trees in May below the node (T6) or above the node (T3) respectively.Contrarily, these values on check tree were (80.97%) as an av. of studied seasons, respectively.Hence the corresponding increment percentages for such trait over check treatment were (6.54 & 6.03%) respectively.On other side, the percentage of peel significantly decreased due to use any pruning methods compared to unpruned.The least peel % was recorded due to prune the trees at May below the node (T6, 10.16%) followed by pruned trees at May above the node (T3, 10.50%).Whereas the highest peel fruit % was recorded on trees that unpruned (control, 14.10%) as an av. of two studied seasons.Hence, the decrement % of peel was attained (27.94 & 25.53%) either due to prune below or above node compared to unpruned one, respectively.
The best yield components and fruit characters were recorded on pruned shoots in May below node (T6) during the two studied seasons.On other hand, the worse results were recorded on unpruned trees (control) (T1) during the two studied seasons.
Typically, we can conclude that pruning trees in May or August above or below the node improved the productivity of Naomi mango trees.Moreover, the pruning below the node is better than pruning done above it.4-Prune August above node (T4).5-Prune in March below node (T5).6-Prune in May below node (T6).7-Prune in August below node (T7).The results showed that pruning trees below nodes is better than pruning above this unit.This finding maybe due to the transferring the carbohydrates and nutrients contained in the remaining part of the wood to the new growth increasing its growth.
Olivira et al, (2017), mentioned that pruning of all kinds, has in effect on the mango crop.It is also important that may emerge or not, and, accordingly, the growth of height with increased density of cultivation is that the way the plant is trained is important, (Sousa et al., 2012).mango trees that divide the shape at 5 meters x 4 m dramatically not reduce the : A-Total soluble solids percentage (T.S.S. %): Was estimated by hand refractometer.b-Total and reducing sugars: -The percentages of reducing and total sugars were determined according to the volumetric method of Lane and Eynon outlined in A.O.A.C. (2000).C-Total acidity: -The percentage of acidity was determined according to A.O.A.C. (2000).

Table ( 5): Effect of pruning methods on chemical properties of Naomi mangos during 2021 and 2022 seasons
Prune in March below node (T5).6-Prune in May below node (T6).7-Prune in August below node (T7).