Effect of boron fertilizers on mango yield

The importance of boron fertilizers. Boron is a key micronutrient that affects the growth and development of plants, including fruit trees such as mangoes. The use of boron-containing fertilizers has become an important tool for improving tree productivity and crop quality in many regions of the world. In this article, we will conduct a comparative analysis of the effectiveness of boron fertilizers and their impact on key yield indicators such as fruit number, size, flavor, and disease resistance. So let’s get started! 

Deficiency of trace elements in the soil is one of the main reasons for the poor quality of mango fruits and low yield. In addition, the consumption of such fruits also causes micronutrient deficiencies in humans. Boron deficiency negatively affects flowering and the formation of pollen tubes, which leads to a decrease in the yield and quality of mangoes. Soil and foliar fertilizing with boron is considered a productive method of overcoming boron deficiency.

Boron as a nutrient acts as a regulator of the synthesis of stimulators and inhibitors of plant growth.

Boron as a trace element:

1. Needed by plants throughout the growing season, because it regulates the synthesis and transport of carbohydrates and ascorbic acid from the leaves to the fruiting organs.
2. Under the influence of boron, plants bloom earlier and produce seeds, diseases are sharply reduced and seed productivity increases.
3. Numerous scientific studies on the effect of boron on the growth and development of plants are focused on its positive effect on the fertilization of flowers and the formation of fruits.

The purpose of this study was to investigate the effect of three boron-containing fertilizers on the formation of biometric indicators of plants and on the productivity of 10-year-old mango trees.

Materials and methods. Studies on the effect of boron-containing fertilizers on the formation of yield indicators of 10-year-old mango trees Mangifera indica L. were carried out at the  in Dinh Quan District, Donghai Province in Vietnam in January 2023.

Study conditions:

1. The soils of the experimental site are acrisols (soils with subsurface accumulation of low-activity clay minerals and low base saturation (from the Latin acris, which means very acidic). Acrisol is a highly weathered soil found in moderately warm regions and humid parts of the tropics and subtropics. Acrisols have poor chemical properties, low levels of plant nutrients, high levels of aluminum and high susceptibility to erosion).
2. The climate of the research area is tropical monsoon; there was no precipitation during the period of fertilizer application.
3. Three boron-containing fertilizers were chosen for research: Wonder Leaf Mono B 11 of the Ukrainian company “Wonder” LLC, Foliar Boron of the English company Omex Agriculture and Boron of the Australian company Nutri-Tech Solutions (Table 1). The consumption rate of each drug is 20 ml per 20 liters of water.
4. The control involved no treatments.
5. Treatment with the studied fertilizers was carried out during the flowering and fruiting phase twice – on January 6 and 14, 2023 (Fig. 1), the assessment of stem biometric parameters (thickness, length) was carried out three times – on January 14 and 24, and March 2, 2023. The productivity was recorded 60 days after the withering of the flowers – from August 10 to 20, 2023.

Table 1

Characteristics of the fertilizers used in the research.

Figure 1. Research conditions

Results and discussion. The effect of boron-containing fertilizers on the formation of biometric indicators of mango plants is shown in Figure 2 (a, b, c).

The results show that foliar application of boron from different sources clearly resulted in a positive effect on the acceleration of reproductive growth of mango compared to control plants. Different aspects of the tree canopy did not show significant variations in the studied parameters. The results of this study show that boron is involved in plant reproductive physiology, i.e., in pollen tube elongation, pollen germination, and translocation of sugars and carbohydrate synthesis.

Picture 2a.

Picture 2 b.

Picture 2 c.

The results of the effect of boron-containing fertilizers on the parameters of mango productivity are shown in Table 2.

Table 2

Effect of boron application on mango Mangifera indica L. fruit yield

Research results indicate the positive influence of boron-containing fertilizers in the formation of biometric indicators and indicators of mango productivity. Thus, when using Wonder Leaf Mono B 11, the average amount of fruits in inflorescence was 5.2 pcs., which exceeded the same indicator when using Foliar Boron by 1.4 pcs. and was smaller by only 0.8 units, compared to the introduction of Boron. The highest value of the weight of the fruit – 169.17 g – was also obtained when using Wonder Leaf Mono B 11.

Regarding the number of fruits on the plant, the largest number was 199.77 pcs. was obtained when applying Boron, exceeding the values obtained from the application of Foliar Boron and Wonder Leaf Mono B 11 by 4.13 and 1.3 units, respectively. The highest yield from one plant – 34.8 kg, as well as from a unit area, was also obtained when using Wonder Leaf Mono B 11.

The positive effect obtained from the use of this fertilizer can be partly explained by its improved composition, because the fertilizer contains phytohormones – auxins, gibberellins and cytokinins, as well as polysaccharides. In addition, the fertilizer is enriched with free amino acids, amino acids that are added to the product separately, and not as part of the protein.

According to research by Venancio et al., 2024, it was established that the application of gibberellic acid during the flowering phase led to higher average values of the number of stenospermocarpic fruits. Cytokinin treatment reduced the number of stenospermocarpic fruits and resulted in higher mean values of the number of productive branches. Boron, auxin, and the combination of gibberellin with boron did not reduce stenospermocarpy indicators. Hormonal balance plays a critical role in the development of stenospermocarpic fruits, with gibberellin associated with the development of this disturbance, while cytokinin has an antagonistic effect. Application of boron and auxin did not have a predominant effect on increasing or decreasing stenospermia. Meanwhile, Nazir et al., 2024 treated 4 mango orchards with combinations of micronutrients, including boron (B), copper (Cu) and zinc (Zn), applied as foliar sprays and in the soil along with recommended doses of nitrogen, phosphorus, and potassium. (NPK) and FYM (farmyard manure).

The effects of these treatments on disease severity (anthracnose) and fruit yield were evaluated by measuring trace element levels in leaves and soil before and after application. The results showed that application of all three trace elements significantly reduced disease severity and increased fruit yield in all orchards. The most effective treatments were observed as H3BO3 (0.8%) + CuSO4 (0.5%) + ZnSO4 (0.8%) and Bura (200 g of plant (-1)) + ZnSO4 (400 g of plant (-1)) + CuSO4 (200 g plants (-1)), which reduced disease damage by 26 and 21%, respectively, and yielded up to 392 and 371 kg, respectively. The current study showed that the use of micronutrients could be a potential way to reduce mango anthracnose disease in integrated disease management programs.

These and other studies indicate a wide range of applications of boron in mango nutrition systems, both to improve the formation of flowers, fruits and branches, increase fruit yield, and to protect plants from diseases.

Boron, as a constituent element of the plant nutrition system, plays and will play an extremely important role in terms of its influence on the formation of flowers, fruit setting, increasing yield and increasing the resistance of plants to harmful objects. In this context, the use of boron-containing fertilizers acts as a factor in the intensification of crop cultivation, with a view to complying with scientifically based recommendations on nutrition.