1、Foliar Fertilization of Crop Plants: Journal of Plant Nutrition: Vol 32 , No 6

Soil application method is more common and most effective for nutrients, which required in higher amounts. However, under certain circumstances, foliar fertilization is more economic and effective.

2、Foliar Fertilization for Sustainable Crop Production

Here I review the extensive work that has been carried out on the effectiveness of foliar-applied nutrients, the mechanisms of foliar absorption, and transport.

3、The Effects of Foliar Sprays with Different Silicon Compounds

In this review, the effects of foliar sprays with different Si compounds will be presented. The rationale for this review is to provide an up-to-date systematic overview of the different types of foliar feeding with Si compounds [14, 15].

Studies on the influence of foliar nutrient sprays on the root exudation pattern in four crop plants

Foliar application of nitrogen in the form of NaNO 3 and phosphorus as Na 2 HPO 4, was found to alter the exudation pattern of amino acids and sugars and such influence differed in different plant species.

Foliar spraying with silicon and selenium reduces cadmium uptake and mitigates cadmium toxicity in rice

These findings demonstrate that foliar spraying with Si and Se is effective in reducing Cd accumulation in rice cultivars with high Cd translocation ability, mainly by reducing stem Cd concentrations and ameliorating plant photosynthetic processes.

Concepts and applications of foliar spray for microbial inoculants

The antagonistic effect of the two species varied with Fusarium isolates and in effective period after application; hence, the combined foliar application of both strains was most successful (Panwar et al. 2014).

Microsoft Word

Concerning the effect of microelements on yield components, data presented in Table 6 indicated that application of micronutrient mixture as foliar spray was generally more effective than the control plants in both seasons of study.

Effects of foliar dressing of selenite and silicate alone or combined with different soil ameliorants on the accumulation of As and Cd and antioxidant

The results of this study showed that the root application of silicon fertilizer alone did not reduce leaf Cd concentration, but its combination with the spraying application of Si or Se reduced the leaf Cd concentration to be lower than its Chinese national standard.

Foliar application of zinc sulphate and zinc EDTA to wheat leaves: differences in mobility, distribution, and speciation

When ZnSO 4 and ZnEDTA fertilizers are used for foliar application, it is unclear which treatment is more efficacious; results vary depending on what parameter is used to define ‘agricultural efficacy’.

Foliar Application: A Thriving and Flourishing Domain in Agriculture

Foliar spraying is also beneficial in dry conditions where there is little soil moisture, as plants are able to assimilate urea through the leaves [1,6]. Just 2 to 4kg of urea can be dissolved in 100 litres of water can be effectively used for foliar spray.

Brassinosteroid, also known as brassinolide, kokusanol, or rapemaster, is a plant growth regulator. It primarily functions by inhibiting abscisic acid biosynthesis, promoting cell division and elongation, enhancing stress resistance, and improving crop growth, yield, and quality. In agricultural production, both foliar spraying and root application of brassinosteroid are common methods, but their effectiveness varies.

1. Foliar Application:

Foliar application involves directly spraying the brassinosteroid solution onto plant leaves. This method is simple to operate and allows precise control over dosage and concentration. the waxy cuticle layer on leaf surfaces often forms a protective barrier, hindering absorption. Additionally, limited uptake through stomata further restricts effectiveness. Thus, foliar spraying is generally weaker in effect and更适合用于幼苗期或对芸苔素敏感的作物（suitable for seedlings or crops highly sensitive to brassinosteroid）.

2. Root Application:

Root application involves applying the solution directly into the soil near the plant’s root system. This method ensures effective absorption and higher utilization rates. deeper root systems may require multiple applications to achieve optimal results. improper use could potentially damage roots and disrupt normal growth. This approach is more suitable for field crops or plants with higher tolerance to brassinosteroid.

3. Comparative Effectiveness:

Foliar Spraying:

• Weaker effectiveness: Absorption is limited by the waxy cuticle and stomata.
• Limited applicability: Best for seedlings or sensitive crops.

Root Application:

• Better effectiveness: Ensures efficient absorption and higher utilization.
• Broader applicability: Suitable for field crops or tolerant plants.

4. Practical Recommendations:

Select the application method based on crop type, growth stage, and sensitivity to brassinosteroid. For seedlings or sensitive crops,优先采用喷叶施用（foliar spraying is preferred）. For field crops or tolerant plants,根灌更有效（root application is more effective）. Always monitor dosage and concentration to avoid phytotoxicity from overuse.

both foliar spraying and root application have distinct advantages and limitations. The choice should align with crop type, growth stage, and sensitivity. Proper use of brassinosteroid can enhance stress resistance, increase yields, and support agricultural productivity.