Modeling of P-Loss Risk and Nutrition for Mango (Mangifera indica L.) in Sandy Calcareous Soils: A 4-Years Field Trial for Sustainable P Management

The aim of this study was to quantify the effect of different varieties, planting densities, tree training systems and canopy aspect (north and south) on tree water use efficiency and nitrogen (N) availability in relation to mango fruit yield and fruit size as well as soil fertility (particularly total carbon (C) and total N as well as C and N isotope compositions) in a 5-year-old mango plantation of tropical Australia. Mango foliar samples were collected from a 5-year-old, factorial field experiment, where we tested the effects of two mango varieties (Calypso vs Keitt); two planting densities (medium vs high); two training systems (single leader vs conventional); and two sampling canopy aspects (north vs south) on foliar total C (%), total N (%), and stable C and N isotope compositions (δ13C and δ15N). The 0–10 cm of surface soils were also assessed for total C, total N, and δ13C and δ15N of different varieties, planting densities, and training systems. In addition, mango fruit yield, and fruit size were measured. There were significant genetic effects on foliar total N, tree water use efficiency (WUE) as reflected by foliar δ13C, N availability as indicated by foliar total N and δ15N, mango fruit yield, and fruit size in 5-year-old mango trees in tropical Australia. Overall, Keitt had higher foliar δ13C and N availability (higher total N and lower δ15N) as well as higher mango yield and greater fruit size, compared with those of Calypso. There were also significant environmental influences on foliar δ13C and N availability. In particular, high planting density had higher N availability (higher total N), and lower foliar δ13C as well as higher N loss (higher δ15N), compared with those of medium planting density. High planting density treatment also had higher soil total N, compared with that of medium planting density treatment. The conventional training system had higher N availability and foliar δ13C, compared with those of the single leader training system. The northern side of tree canopy (sunny side) had lower fruit number, compared with that of the southern side (shady side) of tree canopy. There were significant genetic and environmental influences on tree WUE and N availability as well as mango fruit yield and fruit size in the 5-year-old mango trees. Among them, Keitt’s fruit was significantly larger than Calypso and had higher foliar δ13C (higher WUE). Although high planting density increased soil total N, it also resulted in lower foliar δ13C and more N loss. Our results highlighted the significant potential for improvement of foliar δ13C and N availability as well as fruit yield and soil fertility with both genetic selection and site management regimes.

The experiment was carried out 2015-16 in Mango orchard at Fruit Research Station Kuthulia, College of Agriculture Rewa (M.P). The study revealed that the Effect of micronutrients on growth, yield and fruit quality of mango (Mangifera Indica L.) cv. Dashehari with 7 treatments in Randomized Block Design with three replications, Observations were recorded on growth yield & quality parameters. The maximum plant height was recorded (9.59m) in Treatment T4, RDF + Foliar spray of 0.4% Zinc sulphate + 0.2% copper sulphate + 0.2% Boric acid (2 Spray at just before flowering and marble stage) followed by (9.03m) treatmentT5, RDF + Zinc sulphate 100 g + Copper sulphate 50 g + Boric acid 50 g (soil application) in basin after harvest + Foliar spray of 0.2% Zinc sulphate + 0.1% Boric acid (2 Spray at just before flowering and marble stage. The maximum plant spread was recorded (Mean of N-S 11.93m E-W 12.87) in treatment T2, RDF + Zinc sulphate 200 g + Copper sulphate 100 g + Boric scid 100 g (soil application) in basin after harvest. The maximum number of fruits per plant was recorded (288.00) in treatment T5, RDF + Zinc sulphate 100 g + Copper sulphate 50 g + Boric acid 50 g (soil application) in basin after harvest + Foliar spray of 0.2% Zinc sulphate + 0.1% Boric acid (2 Spray at just before flowering and marble stage) However the maximum tree volume (1100.79 m3) was recorded in treatment T4, RDF+ Zinc sulphate 0.4%+ Copper sulphate 0.2% + Boric acid 0.2%(2 spray at just before flowering and marble stage). The maximum length and width of fruit were recorded (10.67cm), (5.97cm) in treatment T5, RDF+ Zinc sulphate 100g + Copper sulphate 50g + Boric acid 50g (soil application) + Zinc sulphate 0.2%+ Boric acid 0.1%(2 spray at just before flowering and marble stage). The maximum fruit yield was recorded (64.04kg/tree) in treatment T5, RDF + Zinc sulphate 100 g + Copper sulphate 50 g + Boric acid 50 g (soil application) in basin after harvest + Foliar spray of 0.2% Zinc sulphate + 0.1% Boric acid (2 Spray at just before flowering and marble stage). The minimum fruit yield was recorded (29.55kg)in treatment T7control RDF only. The maximumpulp percentage was recorded (79.94%) in treatment T5, RDF+ Zinc sulphate 100g + Copper sulphate 50g + Boric acid 50g (soil application) + Zinc sulphate 0.2%+ Boric acid 0.1%(2 spray at just before flowering and marble stage) The maximum acidity was recorded (0.26%) in treatment T4, RDF + Foliar spray of 0.4% Zinc sulphate + 0.2% copper sulphate + 0.2% Boric acid (2 Spray at just before flowering and marble stage).The maximum total soluble solids (TSS) was recorded(21.13 0Brix) T5, RDF + Zinc Sulphate 100 g + Copper sulphate 50 g + Boric acid 50 g (soil application) in basin after harvest + Foliar spray of 0.2% Zinc sulphate + 0.1% Boric acid (2 Spray at just before flowering and marble stage).

A field experiment was conducted on a silty clay soil in the Gangetic plain of West Bengal for two consecutive years (2008–09 to 2009–10) to assess the drip vis-a-vis surface irrigation under varying levels of NPK fertilizers on fruit yield, nutrient uptake, water use efficiency and quality of banana. The treatments consisted of three drip irrigation levels at 50, 60 and 70% of cumulative pan evaporation (CPE) and three fertigation levels at 50, 60 and 80% of recommended dose of NPK fertilizers including surface irrigation at IW/CPE 1.0 laid out in an augmented factorial complete block design with three replications. The results of the study showed that fruit yield, yield components and quality parameters of banana increased with increasing levels of drip irrigation and fertigation. Maximum fruit yield (46.59 t/ha), yield components and quality attributes was observed in drip irrigation at 60% of CPE with 80% of recommended dose of NPK fertilizers applied through drip system. However, leaf nutrient uptake was relatively higher in drip irrigation at 70% of CPE with 80% of recommended dose of NPK fertilizers. Maximum crop water use efficiency (0.40 t/ha-cm) was registered in drip irrigation at 60% of CPE with water savings of 39.7% over surface irrigation. Thus, application of drip irrigation at 60% of CPE with 80% of recommended dose of NPK fertilizers through drip-fertigation was found to be the best option in obtaining of higher fruit yields, yield components and quality of produce. Alternatively, surface irrigation at IW/CPE 1.0 could also be advocated with almost same efficiency if the initial investment for laying the drip irrigation system is an impediment for the banana growers of the region.

The present investigation was conducted in 2024 -25 at Department of Fruit Science, Pt. K.L.S. CHRS, Pendri, Rajnandgaon (C.G.) India to evaluate the effect of plant growth regulators (GA₃ and NAA) and micronutrients (ZnSO₄ and Borax) on fruit yield and quality of mango (Mangifera indica L.) cv. Dashehri. The experiment comprised fifteen treatments and three replications. Individual, and combined applications of growth regulators and micronutrients, laid out in a randomized block design (RBD). Significant variations were observed among treatments for fruit yield, fruit volume, total soluble solids (TSS), reducing and non-reducing sugars, and titratable acidity. The combined application of NAA @ 20 ppm + Borax @ 0.2% (T8) recorded the highest fruit yield (69 kg/tree), maximum fruit retention at pea, marble, and pre harvest stages, highest fruit setting percentage (0.7%) and highest number of fruits per panicle (4.93). Whereas maximum fruit weight, TSS, and total sugar content with the lowest acidity recorded under T13 (NAA @ 20 ppm + ZnSO₄ @ 0.5%). In contrast, the treatment T0 (control) recorded the minimum values for all parameters. The results suggest that the combined use of growth regulators and micronutrients improves fruit yield and quality attributes of mango cv. Dashehri.

The present investigation was conducted during 2019 at DAV University, Jalandhar, to find out the effect of organic manures and chemical fertilizers on the growth and yield of summer squash (Cucurbita pepo L.) cv. Punjab Chappan Kaddu. The experiment consisted of eleven treatments and three replications. Out of these, an application of 25% of the recommended dose of chemical fertilizer + vermi-compost 15t/ha (T8) had a beneficial effect on minimum days to the first female flower (74.67 days), minimum days to the first fruit set (76.33), minimum days to the first fruit harvest (78.33). The maximum plant height (122.85cm) was recorded in 25% of the recommended dose of chemical fertilizer + FYM 25t/ha (T5). 75% of the recommended dose of chemical fertilizer + EM (Effective Micro-organism) Bokashi 2.5q/ha (T9) resulted in minimum days to male flower appearance. The maximum sex ratio (0.38), was obtained with the application of 50% of the recommended dose of chemical fertilizer + EM Bokashi 3q/ha (T10). The maximum number of pickings (26) and number of fruit per plant (9.85) were obtained with the application of 50% of the recommended dose of chemical fertilizer + EM Bokashi 3q/ha (T10). The maximum fruit yield per plant (2.20 kg), fruit yield per plot (26.26 kg), fruit yield per ha (405.57q) were recorded with the application of 50% of the recommended dose of chemical fertilizer + vermi-compost 15t/ha (T7). The maximum Total Soluble Solids (TSS) (2.40B°) were recorded with the application of 75% of the recommended dose of chemical fertilizer + FYM 20t/ha (T3) while, the ascorbic acid was maximum (52.50 mg/100g) when 25% of the recommended dose of chemical fertilizer + vermi-compost 15t/ha (T8) were applied. The highest net returns and benefit: cost (4.5) were obtained when 50% of recommended dose of chemical fertilizer + FYM 25t/ha (T4) was applied.

Evidence for self-compatibility and variation for inbreeding depression within breeding populations of fennel (Foeniculum vulgare Mill.)

Experiment was conducted at Melkassa Agricultural Research Center, centeral rift valley of Ethiopia from September 2008 to January 2009 with the objective to determine the effects of different concentrations and combinations of 2,4-dichlorophenoxyacetic acid (2,4-D) and gibberellic acid (GA3) spray on fruit yield and quality of tomato. The experiment consisted of two tomato varieties-one processing (Roma VF) and one fresh market (Fetan), three levels of 2,4-dichlorophenoxyacetic acid (2,4-D) (0, 5 and 10 mg l-1) and four levels of gibberellic acid (GA3) (0, 10, 15 and 20 mg l-1) arranged in 2 × 3 × 4 factorial combinations, in Randomized Completed Block Design with three replications. The result showed that increased in fruit length from 5.44 to 6.72 cm at 10 mg l-12,4-D combined with 10 mg l-1 GA3 above the control. Increased fruit weight by 13% due to 2,4-D and reduced fruit weight in single or combined application of GA3 with 2,4-D. Fruit pericarp thickness was increased by about 50% due to 2,4-D and GA3 application above the control. Titratable acidity, total soluble solids and lycopene content were also increased due to combined application of 2,4-D and GA3 spray. Lower fruit pH is another quality attributes of tomato affected by 2,4-D application while that of GA3 has no effect. Final fruit yield were significantly improved above the control even though both varieties responded deffirently. For Roma VF, GA3 at concentration of 10 and 15 mg l-1 resulted in maximum fruit yield of 69.50 and 67.92 ton ha-1, respectively in the absence of 2,4-D. For Fetan, maximum marketable fruit yield of 74.39 and 74.20 ton ha-1 was obtained from treatment combinations of 10 + 15 and 5 + 0 2,4-D and GA3, respectively. Hence, yield increment of about 35% for Roma VF and 18% for Fetan were produced at 10 mg l-1 GA3 and 10 + 15 mg l-1 2,4-D and GA3, respectively over the control. Significant increase in fruit size and weight due to 2,4-D and increased fruit number due to GA3 spray contributed to increased fruit yield. The results indicated that both PGRs are important in tomato production to boost yield and improve fruit quality under unfavorable climatic conditions of high temperature. Therefore, it is important to further investigate application methods and concentrations of the PGRs under concern in different growing conditions on different tomato cultivars. Key words: Gibberellic acid, 2,4-dichlorophenoxy acetic acid, tomato,Lycopersicon esculentum Mill, fruit yield, quality.

Reducing fertilizer doses under sustainable agricultural management is possible by increasing nutrient utilization efficiency, which will decrease crop production costs and boost economic return. Soil amendments known as water retention agents (WRAs) are added to the soil to enhance crop growth conditions. We hypothesize that the addition of WRAs may support the soil-retaining nutrients given through fertilization and prevent them from leaching into tropical soils characterized by severe rainfall due to WRAs’ exceptional capacities to absorb and store water. Mango trees (Mangifera indica L. cv Tainong No. 1) aged 18 years were fertilized with 100% or 80% of the recommended doses of nitrogen (N), phosphorus (P), and potassium (K). The experimental design included three treatments, i.e., complete recommended doses of N, P, and K (CRF), 80% of the complete recommended doses (RRF), and water-retaining agent (40 kg ha−1) + 80% of the complete recommended doses (WRARRF). Reducing the fertilization doses by 20% for mango trees in the studied tropical soil significantly (p < 0.05) minimized the nutrient availability in the soil compared to the complete fertilization doses. WRARRF compensated for the nutrient reduction by increasing the availability of N, P, and K. The addition of WRARR increased N, P, and K in mango leaf by 11%, 4%, and 7% in the first year and by 11%, 6%, and 7% in the second year, respectively, compared to CRF. The addition of WRARR increased the partial fertilizer productivity (PFP) value by 36% and 41% in the first and second years, respectively. The highest mango fruit output was achieved by the addition of WRARRF, which resulted in increases in mango fruit yield of 11.9% and 16.5% in the first and second years, respectively, compared to RRF. Fruit quality traits showed the descending order: WRARRF > RRF > CRF. WRARRF produced the maximum economic benefit (USD 7372 per hectare) compared to CRF and RRF. The polyacrylamide/attapulgite water-retaining agent exhibited remarkable improvement in mango fruit yield and economic profit by regulating the release of nutrients in tropical soils. Water-retaining agents are an effective strategy for overcoming the extensive fertilization used in mango orchards, which has resulted in numerous environmental contaminations and the inefficient use of fertilizers.

The present experiment was conducted under the semi-arid subtropical red lateritic zone of eastern India in West Bengal with seven years old popular mango (Mangifera indica L.) varieties grown at Horticulture Research Farm of Department of Horticulture and Postharvest Technology, Institute of Agriculture, Visva-Bharati, Sriniketan, West Bengal, India during 2015 and 2016. The varieties were evaluated for various morphological characters, yield and physicochemical quality of fruits. The results revealed that Kohinoor exhibited maximum tree volume (41.99 m3), fruit yield (21.03 kg/tree) and fruit weight (253.33 g/fruit). Whereas, Kohitoor exhibited maximum TSS (20.07 oB), TSS/acid ratio (100.35) and ascorbic acid (43.17 mg/100g) content of the fruits. Acidity content was found lowest (0.17%) in Gulab Khas. Regarding morphological characters, yield and physicochemical quality of fruits, the varieties Kohinoor, Kohitoor, Inayat Pasand are superior in quality and stand to promise for the small family farming orchard in the red lateritic zone of eastern India.

An on-farm trail (OFT) on assessment of flowering season of pomegranate was tested. The experiment was conducted with three treatments comprising mrig bahar flowering as a control and hast bahar flowering with and without application of micronutrients and kaolin clay during June to February for three consecutive years from 2019–2022 in the different farmer fields at the Tharad taluka of Banskantha district, Gujarat, India. The treatment T1 Mrig bahar (June-July) flowering recorded the maximum total number of flowers (293.67) hermaphrodite flowers (108.9) and fruit setting (71.85%). Further, T1 exhibited the highest average number of fruits plant-1 (79.0) and maximum fruit yield (11.78 kg plant-1) followed by T3 and T2 treatments (10.14 kg plant-1 and 9.02 kg plant-1) respectively. In terms of total fruit yield, Treatment T1 exhibited the highest fruit yield of (9813 kg ha-1). Whereas, maximum individual fruit weight 179.44 g plant-1 and Total Soluble Solids (15.75°Brix) were found in Treatment T3. Moreover, treatment T3 Hast Bahar (Sept–Oct) flowering with foliar spray of micromix 0.2% and kaolin Clay 4.0%) has the lowest average fruit cracking (6.30%) and the lowest incidence of sunburn (8.80%) across the three years. However, treatment T1 recorded highest average fruit cracking (18.90%). Further, during the Mrig bahar season, incidence of leaf spots and fruit rot was observed higher compared to the Hast bahar flowering. In case of economics, treatment T3 obtained the highest average income of 411813 ha-1 as compared to treatment T2 and T3 ` 353074 ha-1 and 333425 ha-1, respectively.

<p><strong>Purpose:</strong> This study was aimed to quantify the effect of different variety, planting density, training system and canopy position on tree water and nitrogen use efficiencies in relation to mango fruit yield and size as well as soil fertility in a 5-year-old mango plantation of tropical Australia.</p><p><strong>Material and Methods:</strong> Soil (0-10 cm) and mango foliar samples were collected from a 5-year-old, factorial field experiment testing the effects of two mango varieties (Calypso vs Keitt), two planting densities (medium vs high), two training systems (single leader vs conventional) and two sampling canopy positions (north vs south) on foliar total carbon (TC, %), total nitrogen concentration (TN, %), and stable carbon (C) and nitrogen (N) isotope compositions (δ<sup>13</sup>C and δ<sup>15</sup>N) as well as the corresponding total C, total N and δ<sup>13</sup>C and δ<sup>15</sup>N in the surface soil of tropical Australia. In addition, mango fruit yields and sizes were determined. Soil and foliar total C and N as well as δ<sup>13</sup>C and δ<sup>15</sup>N were determined on mass spectrometers at Griffith University. Each of the above treatment was replicated 6 times for foliar samples and 3 times for soil samples.</p><p><strong>Results:</strong> There were significant genetic effect on foliar total N concentration (TN, %), tree water use efficiency (WUE) as reflected by foliar δ<sup>13</sup>C, N use efficiency (NUE) as indicated by foliar TN and δ<sup>15</sup>N, mango fruit yield and sizes in the 5-year-old mango plantation of tropical Australia. Overall, mango variety of Keitt had higher tree WUE and NUE as well as higher mango yield and greater fruit size, compared with those of mango variety of Calypso. There were also significant environmental influences on mango tree WUE and NUE as well as mango yield and fruit size. In particular, high planting density had higher tree NUE, and lower WUE as well as higher N loss, compared with those of medium planting density. High planting density treatment also had higher soil total N, compared with that of medium planting density treatment. The convention training system also had higher tree NUE and WUE, compared with the single leader training system. The northern side of tree canopy (sunny side) had lower fruit number, compared with the southern side (shady side) of tree canopy.</p><p><strong>Conclusion:</strong> There were significant genetic and environmental influences on tree WUE and NUE as well as mango fruit yield and sizes in the 5-year-old mango plantation, highlighting the significant and exciting opportunities to improve mango tree WUE and NUE as well as fruit yield and soil fertility with both genetic selection and site management regimes.</p>

Under sub-tropical region, poor fruit set is a major constraint in semi-soft pears resulting in lower fruit yield. To study the effect of plant growth substances on fruit production and quality, the plants of pear cv. Punjab Beauty were sprayed with the plant growth substances viz., boric acid (200, 300 ppm), CPPU (5, 10 ppm), NAA (10, 20 ppm) and P-Ca (150, 300 ppm) at full bloom stage. Among all the applied treatments, boric acid @ 200 ppm proved to be most effective with maximum fruit set (6.91 %), fruit retention (59.9 %) and yield (57.8 kg/plant), while, maximum fruit weight (162.3 g) was observed with NAA (20 ppm). The highest internal fruit quality in terms of maximum TSS (12.4o Brix), TSS/acid ratio (53.4) and ascorbic acid (12.8 mg kg-1) was observed in 200 ppm boric acid. However, the total phenol (30.9 mg GAE/100 pulp) and flavonoid (36.1 mg CE/100 pulp) content was significantly higher with NAA (20 ppm). The plant growth substances reduced the polyphenol oxidase activity in fruits. Overall, the application of boric acid (200 ppm) resulted in improved fruit set, yield and quality in pear cv. Punjab Beauty.

Under sub-tropical region, poor fruit set is a major constraint in semi-soft pears resulting in lower fruit yield. To study the effect of plant growth substances on fruit production and quality, the plants of pear cv. Punjab Beauty were sprayed with the plant growth substances viz., boric acid (200, 300 ppm), CPPU (5, 10 ppm), NAA (10, 20 ppm) and P-Ca (150, 300 ppm) at full bloom stage. Among all the applied treatments, boric acid @ 200 ppm proved to be most effective with maximum fruit set (6.91 %), fruit retention (59.9 %) and yield (57.8 kg/plant), while, maximum fruit weight (162.3 g) was observed with NAA (20 ppm). The highest internal fruit quality in terms of maximum TSS (12.4o Brix), TSS/acid ratio (53.4) and ascorbic acid (12.8 mg kg-1) was observed in 200 ppm boric acid. However, the total phenol (30.9 mg GAE/100 pulp) and flavonoid (36.1 mg CE/100 pulp) content was significantly higher with NAA (20 ppm). The plant growth substances reduced the polyphenol oxidase activity in fruits. Overall, the application of boric acid (200 ppm) resulted in improved fruit set, yield and quality in pear cv. Punjab Beauty.

Poor fruit retention and low yield are major production constraints in Alphonso mango, often attributed to imbalanced nutrient management. A field experiment was conducted during 2023-24 and 2024-25 at the Centre of Excellence for Mango, College of Horticulture, Dapoli, to study the effect of different soil and foliar nutrient application strategies on fruit retention, yield and quality of mango (Mangifera indica L.) cv. Alphonso. The experiment was laid out in a Factorial Randomized Block Design with four nutrient management treatments comprising F1- recommended dose of fertilizers (RDF), F2- RDF in split application, F3- RDF with foliar application of Amrashakti (2.5%) and F4- RDF with foliar application of KNO3 (1%), in combination with irrigation and mulching treatments. Results revealed that F2- RDF in split (N-30% P-40% K-20% after harvest, N 30% P-40% K-20% during fruit set, N-20% K-30% at marble stage, N-20% P-20% K-30% egg stage) significantly improved fruit retention (6.71%), number of fruits per tree (134.50) and fruit yield (34.76 kg/tree) compared to other treatment. Improved fruit quality in terms of fruit weight (254.46 g), fruit length (9.69 cm), fruit width (8.23 cm), pulp:stone ratio (5.21) and spongy tissue incidence (5.94%) was also recorded under same treatments. The study indicated that split application of nutrient is essential for enhancing productivity and fruit quality of Alphonso mango under Konkan agro-climatic conditions.

Low productivity and severe fruit drop are major constraints in Alphonso mango cultivation in the Konkan region, primarily due to improper nutrient and water management. A field experiment was conducted during 2023-24 and 2024-25 at the Centre of Excellence for Mango, College of Horticulture, Dr. Balasaheb Sawant Konkan Krishi Vidyapeeth, Dapoli, to study the combined effect of nutrient application and irrigation on fruit retention, yield and quality of mango (Mangifera indica L.) cv. Alphonso. The experiment was laid out in a Factorial Randomized Block Design (FRBD) with twelve treatment combinations comprising four nutrient management practices (F1-F4) and three irrigation-mulching regimes (I1-I3) replicated thrice. Results revealed that the combined application of RDF in split (N-30% P-40% K-20% after harvest, N-30% P-40% K 20% during fruit set, N-20% K-30% at marble stage, N-20% P-20% K-30% egg stage) + irrigation and mulching (F2I3) recorded significantly higher fruit retention (7.28%), number of fruits per tree (145.50) and fruit yield (38.23 kg/tree) compared to other treatments. Improved fruit quality parameters such as fruit weight (263.93 g), fruit length (10.06 cm), fruit width (8.56 cm) pulp: stone ratio (5.54), total soluble solids (18.73 0Brix), titratable acidity (%) and minimum days from flowering to harvest (115.77 days) and spongy tissue incidence (2.33%) were also observed under the same treatment. The enhanced performance may be attributed to improved nutrient availability, better soil moisture status and reduced physiological stress during critical stages of fruit development. The study concluded that integrated nutrient management combined with irrigation and mulching is essential for improving productivity and fruit quality of Alphonso mango under Konkan agro-climatic conditions.