Impact of Soil Application of Farm Yard Manure, Pigeon Wilt and Humic Acid on Vegetative Growth, Yield and Fruit Quality of “Kiet” Mango Cultivar

This study was carried out during two successive seasons 2021 and 2022 on the Thirteenth-year-old Mango ( Mangifera indica L.). cv. Keit cultivar trees grafted on sokary stone and grown in Al-Busaili - Central Laboratory for Agricultural Climate of the Agricultural Research Center at the North West of the Nile Delta, Rashid Center, Beheira governorate, Egypt. The trees are grown in a greenhouse to impact the soil application of farmyard manure, pigeon wilt and humic acid on vegetative growth, yield and fruit quality of “Kiet” mango cultivar. The distance between trees was 2.0 m and the distance between rows is 2.0 meters. This factorial experiment consisted of thirteen treatments arranged in a Randomized Complete Block Design (RCBD) design with five replicates for each treatment and one tree for each replicate. The treatment consisted of 13 treatments (control, farmyard (5, 10 and 15kg), mixture of farmyard with pigeon wilt and humic acid). Results showed that the treatment of OM at 15 kg + 1/2 kg HA+ 3.5 kg Pio. recorded the best values of fruit weight, the number of fruit and yield/plant, physical characters i.e. (fruit length, fruit width, pulp weight and fruit firmness), and all chemical compositions i.e. (TSS, TSS/ acidity, vitamin C content, total sugars, reducing sugar and non-reducing sugar percentage), as compared with the control treatment which recorded the minimum values of this studied characters, during both seasons.

Pakistan and Brazil (FAO, 2017). Because of the constant population increase, the consumption of food resources is more, resulting there is a lack of food resources. Nitrogenous fertilizers known as chemical fertilizers are inorganic in nature and contain high cost, cause considerable damage to soil, and the environment and also harm human health when it is used in high quantity. Recently, most countries moved for searching natural alternatives which are able to replace the use of chemical/ inorganic fertilizers or pesticides and can reduce the pollution of the environment as well as the cost of agricultural production (Alalaf, 2019).
Biostimulants are synthetic or natural substances that can be applied to soil and plants that cause change to structural or vital physiological processes to enhance plant growth by improving resistance to abiotic stresses Bio stimulants such as humic acid and vermiwash have proven to be beneficial organic amendments to be used in the current scenario of an increasing trend of organic farming. It has reduced the dependency on inorganic fertilizers in order to achieve sustainability without compromising the quality and quantity. Humic acid is a natural resource that can be used as an alternative to inorganic fertilizers. Humic acid is a naturally existing polymeric organic compound that is converted due to the decay of organic matter and initiated in humus, peat as well as lignite (Sharif et al., 2002). Humic acid consists of a combination of organic acids which are aromatic in nature and contain various heterogeneous functional groups that have impervious interaction with different metal ions such as Mg, Zn, Ca and Cu (Piccolo 2012).
Humic acid and vermiwash play a vital role in the improvement of growth and high yield without compromising quality if supplemented with the nutrients. They are of organic origin, thus ensuring sustainability and rich in essential nutrients, ensuring proper nutrition availability. The incorporation of humic acid and vermiwash is done in two ways viz. foliar application and soil amendment. The effect of these biostimulants was studied in various crops by using different methods of incorporation at different doses. This review focuses on the research done on the usage of these biostimulants and evaluates the result of various studies for future reference and research (Hudda et al., 2020). Therefore, the main objective of this research was to study the impact of soil application of farm yard manure, pigeon wilt and humic acid on vegetative growth, yield and fruit quality of the "Kiet" mango cultivar

MATERIALS AND METHODS
This study was carried out during two successive seasons 2021 and 2022 on the Thirteenth-years-old Mango (Mangifera indica L.). cv. Keit cultivar trees grown in Al-Busaili -Central Laboratory for Agricultural Climate of the Agricultural Research Center at the North West of the Nile Delta, Rashid Center, Beheira governorate, Egypt. The trees are grown in the greenhouse to impact the soil application of farm yard manure, pigeon wilt and humic acid on vegetative growth, yield and fruit quality of "Kiet" mango cultivar. This factorial experiment consisted of thirteen treatments arranged in a Randomized Complete Block Design (RCBD) design with five replicates for each treatment and one tree for each replicate.

Experimental Design:
The experiment was arranged in a Factorial experiment Randomized Complete Block Design (RCBD) design with 13 treatments were applied and each treatment comprised five trees arranged randomly in blocks. The treatments of this experiment could be summarized as follows: 1. Control 2. 5kg faramyard manure (FYM) 3. 5kg faramyard +1/2 kg humic acid 4. 5 kg faramyard + 3.5 kg pigeon wilt 5. 5 kg faramyard + 1/2 kg humic acid + 3.5 kg pigeon wilt 6. 10 kg faramyard manure (FYM) 7. 10 kg faramyard +1/2 kg humic acid 8. 10 kg faramyard + 3.5 kg pigeon wilt 9. 10 kg faramyard + 1/2 kg humic acid + 3.5 kg pigeon wilt 1o.15 kg faramyard manure (FYM) 11.15g faramyard +1/2 kg humic acid 12.15kg faramyard + 3.5 kg pigeon wilt 13.15kg faramyard + 1/2 kg humic acid + 3.5 kg pigeon wilt Data Recorded: Samples from five trees of each experimental plot were taken to determine growth parameters at the end of the season as follows: A) Yield: The produced fruit yield on each replicate tree resulting from the applied treatments was expressed as the number of fruits/tree and weight of fruits in kg/ tree which was attained at the harvest stage.
The yield of each treatment was recorded as yield weight/tree by the multiplying number of fruits × average weight of fruit .

B) Fruit Physical Characteristics:
A sample of 5 fruits per tree from each replicate was collected randomly, i.e. 25 fruits for each of the applied treatment was picked randomly at harvest when the fruits were yellow-colored in both seasons, then transported quickly to the laboratory to determine physical and chemical fruit characteristics. Regarding physical fruit characteristics the following parameters were determined: Average fruit weight (g/ f r u i t ) : Fruit samples were weighted and the average fruit weight for each replicate was calculated. Average fruit length (L) and diameter (D) in cm: were measured by using a hand caliper. Fruit firmness: was expressed as (pound / Inch 2 ) according to (Magness and Taylor, 1982). Flesh firmness was measured on two opposite sides of the fruit using a Magness Taylor pressure tester.

Fruit Chemical Characteristics:
Regarding chemical fruit characteristics, samples of 5 fruits from each replicate tree i.e., 25 fruits for each of the applied treatment was picked randomly at harvest to determine the following parameters: Total soluble solids of fruit juice (TSS %): were used to determine the percentage of TSS b y h a n d r e f r a c t o m e t e r a c c o r d i n g t o C h e n a n d M e l l e n t h i n ( 1 9 8 1 ) . The percentage of total acidity: was determined in fruit juice according to Chen and Mellenthin (1981). Five milliliters from the obtained juice were used to determine the titratable acidity. The titratable acidity was expressed as grams citric acid / 100 milliliters of fruit juice. TSS/ acid ratios: were calculated for each replicate of the applied treatments. Total sugars: were determined in fresh fruit samples according to Malik and Singh (1980). Sugars were extracted from 5-gram fresh weight and determined by phenol sulfuric and Nelson arsenate-molybdate colorimetric methods for total and reducing sugars, respectively. The non-reducing sugars were calculated by the difference between total sugars and reducing sugars.

Vitamin C (Ascorbic acid):
The ascorbic acid content of the juice was determined by titration with 2, 6 dichloro phenol-indo-phenol (A.O.A. C., 1985) and calculated as milligrams per 100 ml of juice.

NPK (%):
The NPK contents were determined in the dry leaves and fruits. Their dry weights were determined following drying in a drying chamber to a constant weight of 75℃ for 72 hours according to Tandon (1995). After dryness, the plant samples were milled and stored for analysis as reported. However, 0.5 g of the leaves and fruits powder was wet-digested with H2SO4+ H2O2 mixture according (Lowther, 1980) and the concentrations of nitrogen (N), Phosphorous (P) and potassium (K) were determined. Total Nitrogen: Total nitrogen was determined in digested plant material calorimetrically by Nessler`s method (Chapman and Pratt, 1978). Nessler solution (35 IK/100 ml d. w. + 20g HgCl2 / 500 ml d. w.) +120 g NaOH / 250 ml d. w. Reading was achieved using a wavelength of 420 nm and N was determined as a percentage at the three growth stages as follows: % N = NH4 % x 0.776485

Phosphorus:
Phosphorus was determined by the Vanadomolyate yellow method as given by Jackson (1973) and the intensity of color developed was read in a spectrophotometer at 405nmat during the three growth stages.

Potassium:
Potassium was determined according to the method described by Jackson (1973) using Beckman Flame photometer at the three growth stages.

Statistical Analysis:
Results of the measured parameters were subjected to computerized statistical analysis using MSTAT package for analysis of variance (ANOVA) and means of treatments were compared using LSD at 0.05 according to Snedecor and Cochran (1990).

A.Yield:
Results in Table (1) show the effect of farmyard manure, pigeon wilt and humic acid on fruit weight, the number of fruits/ tree and the yield/tree of mango during the 2021 and 2022 seasons. Results observed that in the first and second season FYM was affected significantly by the treatment of FYM at 15 kg + 1/2 kg HA+ 3.5 kg Pio. which recorded the higher values of fruit weight, the number of fruits/ tree and yield/tree than other treatments (610.63 and 683.91 g, 58.07 and 65.04 and 35.46 and 44.48kg/ tree), followed by FYM at 10 kg + 1/2 kg HA+ 3.5 kg Pio. (549.57 and 615.51 g, 54.32 and 60.84 and 29.85 and 37.45kg/tree), as compared with the control treatment which recorded the lower fruit weight, the number of fruits/ tree and yield/tree(342.53 and 383.64 g, 33.79 and 37.85 and 11.57 and 14.52 kg/tree), during both 2021 and 2022 seasons. Marzouk and Kassem (2011) found that, the application of organic manures (chicken manure, cow dung and composted domestic refuse either alone or in combinations with mineral NPK on Zaghloul dates did not differ from each other in their effect on yield and fruit quality. While, Magda et al. (2012) found that, increasing humic acid doses from 32 to 48g/tree enhanced the yield and fruiting parameters of Manfalouty pomegranate trees.
These results agree with those obtained by El-Mohamedy and Ahmed (2009) concluded that humic acid caused the highest yield in a number of fruits/tree or weight (kg/tree) compared with untreated trees of mandarin. In this respect, Abbas et al., (2013) showed that kinnow mandarin tree received humic acid at 30 ml and exhibited the highest number of fruits per tree. The positive effect of chicken manure on tree yield could be due to a higher content of organic matter and nitrogen and some nutrients leading to improve the nutritional status of trees surely reflected in tree yield (Kannaiyan, 2002).

B.Fruit Physical Characteristics:
The effect of farmyard manure, pigeon wilt and humic acid on fruit physical properties expressed as fruit length, fruit width, firmness and pulp weight of mango Kiett trees during 2021 and 2022 seasons are presented in Table (2) FYM at 15 kg + 1/2 kg HA+ 3.5 kg Pio. which recorded the higher values of fruit length, fruit width, firmness and pulp weight than other treatments (14.76and 16.53g, 10.78and 12.07,35.38 and 39.63 and 517.98and 580.14), followed by FYM at 10 kg + 1/2 kg HA+ 3. (2013) on olive trees. They found that the highest average fruit size (volume), weight, and shape index (length\ diameter) were recorded from trees that were sprayed with humic. Chen et al. (2004) explained the effect of humic substances as the increase in fruit weight and fruit dimensions as a consequence of HA-S application after fruit set is probably ascribed to the uptake of mineral nutrients by the grapevines, but the possible hormone-like activity of the HA-S (i.e., auxin-, gibberellin-and cytokinin-like activity).

C.Fruit chemical characteristics:
Results pertaining to the effect of farmyard manure, pigeon wilt and humic acid on total soluble solids (TSS), acidity, TSS/acidity, vitamin c, total sugars, reducing sugar and non-reducing sugar of mango Kiett trees during 2021 and 2022 seasons are given in Table  (3). It is apparent from the table that significantly maximum total soluble solid, TSS/acidity and vitamin c were observed in the treatment of FYM at 15 kg + 1/2 kg HA+ 3.5 kg Pio. (19.68 and 22.04 %, 24.86 and 27.85, 44.88 and 50.27, 15.74 and 17.63, 8.56 and 9.58 and 7.19 and 8.05 ), respectively, as compared with control treatments which recorded the lowest mean values of total soluble solids, TSS/acidity and vitamin c (9.62 and 10.78%, 6.55and 7. 33, 25.62 and 28.70, 9.32 and 10.44, 5.07 and 5.67 and 4.25 and 4.76), while significantly maximum of acidity percentage was noted under the control treatment (1.47 and 1.64 %) whereas significantly minimum of acidity percentage recorded with FYM at 15 kg + 1/2 kg HA+ 3.5 kg Pio. (0.79 and 0.89 %), during 2021 and 2022 seasons TSS was observed under the control treatment (9.62 and 10.78 %), during both seasons, respectively. The increase in TSS might be due to the accumulation of sugars and other soluble components from hydrolysis of protein and oxidation of ascorbic acid as reported by Pandey et al. (1990) in ber.
Acidity was slightly decreased with increasing levels of humic acid in both seasons. These results are in accordance with Ferrara and Brunetti (2010) and Abbas et al., (2013) on different fruit crops.
The improvement in the sugar of fruits may be due to the balanced absorption of macro and micronutrients which have exerted a regulatory role as an important constituent of endogenous factors in affecting the quality of the fruits. The carbohydrate reserves of the roots and stems are drawn upon heavily which might have resulted in higher sugar contents in fruits. These findings are in alignment with Dey et al. (2005) in guava.

D.NPK In Leaves:
Results concerning the effect of treatments of farmyard manure, pigeon wilt and humic NPK in leaves during 2021 and 2022 seasons are listed in Table (5). Results cleared that, the available nitrogen, phosphorus and potassium were significantly affected by various treatments. However, the maximum NPK percentages in leaves were observed in the treatment of FYM at 15 kg + 1/2 kg HA+ 3.5 kg Pio. (1.70 and 1.91, 0.598 and 0.670 and 2.88 and 3.22%), followed by FYM at 10 kg + 1/2 kg HA+ 3.5 kg Pio. (1.62 and 1.81, 0.568 and 0.637 and 2.74 and 3.06 %), respectively, whereas significantly minimum NPK percentages were observed under the control treatment (1.00 and 1.12, 0.354and 0.397 and 1.72 and 1.91%), during both seasons, respectively acidon.
The role of humic acid in physiological processes comes through the promotion of enzymes and the transfer of photosynthesis products as well as a role in the division and elongation of cells (Fawzyet al., 2007), leading to increased growth, thus increased leaves mineral content. As well as the role of humic acid in improving the properties of soil, and containing this acid on a number of nutrients (Harper et al., 2000) and therefore increased concentration of these elements in the leaves. These results are in harmony with those reported by EL-Kheshin (2016) on mango trees, (El-Salhy, 2017) on Balady Mandarin. The reasons behind these results might also be that due to that the effect of adding humic acid is limited to its high content of nutrient elements as well as providing a nutrient base that increases the activity of the microorganisms (Tisdale et al., 1997). Khattak and Muhammad (2010) reported that humic substances can ameliorate negative soil properties and improve nutrient uptake under salinity conditions. Humic acid can be improved the efficiency of program fertilization, due to microbiological activity can be stimulated by humic substances, by which it is possible to enhance the uptake of minerals. If an adequate amount of humic substances is present within the soil, then it is fertile soil. So, it can be concluded that humic acid may enhance growth, the uptake of some nutrients, reduce the uptake of toxic elements and could improve plant response to salinity.