1、Response of apple trees to boron fertilization under conditions of low soil boron availability

Boron fertilization, regardless of application mode, increased fruit yield; the efficiency of foliar B sprays was higher than soil B application. Apple fruits of trees fertilized with B to the soil were bigger, more colored, richer in B, and had higher soluble solids concentration, and titratable acidity compared to those of the control trees.

2、Optimum Timing of Foliar Nutrient Sprays

The most relevant influences as known up to date are tabulated. For an optimum yield response to foliar fertilization it is possible that the optimum growth stage of the plant for the timing of foliar nutrient sprays does not necessarily fall within the recommended time interval as dictated by pesticide spraying.

3、Fertilizing Fruit Trees

Applying Nitrogen Based on Annual Growth Rate Stone fruit trees (i.e. peach, cherry, plum and nectarines) can be fertilized at a maximum rate of 1/8 pound of nitrogen per inch of trunk diameter (measured 1 foot above ground level). Apply this amount if the tree’s annual growth is on the low end of the recommendation given in Table 1.

4、Soil boron fertilization: The role of nutrient sources and rootstocks in citrus production

Soil B extracted with hot water and total leaf B positively correlated with doses of the nutrient applied to the trees. Levels of B in the soil and in the leaves did not vary with fertilizer sources. Fruit yield of trees grafted onto Rangpur lime and Swingle citrumelo was more responsive to B doses than those grafted onto Sunki mandarin.

Effects of foliar applications of zinc and boron nano

Results obtained indicate that a single foliar spray with relatively low amounts of B or Zn nano-fertilizers (34 mg B tree −1 or 636 mg Zn tree −1, respectively) led to increases in pomegranate fruit yield, mainly due to increases in the number of fruits per tree.

Effects of foliar applications of boron on citrus fruit and on foliage and soil boron concentration

An experiment was conducted in a 5 year old citrus orchard, for four years, to study the effect of boron (B) containing spray mixtures (nitrogen, phosphorus, potassium + amino acids) on fruit yield and quality and on the foliage B concentration.

Boron and fruit quality of apple

Optimal fruit quality was obtained when fruit B contained 14.7 mg B kg -1 dry wt corresponding with an application of 80 g borax tree -1. It is suggested that B may affect fruit quality through its influence on seed production.

Preliminary report on yield productivity and mineral composition of the fig tree as a function of boron and cattle manure fertilization in Brazil

Fertilization with cattle manure is widely recommended for fig tree crops. Campo-Dall’orto et al. [4] recommend the applica-tion of 10 kg of cattle manure per planting hole, at planting time, and an equivalent amount per plant every year.

Applying boron to coconut palm plants: effects on the soil, on the plant nutritional status and on productivity boron to coconut palm trees

Boron (borax) dosages were applied in equal halves directly into the soil in the months of January and February of 2005. Boron concentration in the soil and plant and plant productivity were evaluated. The higher palm tree production was associated to levels of 0.6mg dm-3 of B in the soil and 23.5mg kg-1 in leaves.

Effect of Postharvest Sprays of Boron and Urea on Yield and Fruit Quality of Apple Trees: Journal of Plant Nutrition: Vol 29 , No 3

Postharvest B spray with/without urea improved flower B status, fruit set, and tree yield. However, the efficiency of combined B spray with urea in improving reproductive growth was lower than that of foliar B application without the addition of urea.

The application of boron fertilizer is a critical practice for improving fruit quality and promoting healthy growth in fruit trees. Boron plays a vital role in plant development, flowering, fruiting, and disease resistance. Below, I will explain the best timing, methods, and precautions for applying boron fertilizer to fruit trees.

1. Optimal Timing for Boron Fertilizer Application

Spring Application

Spring is a crucial period for tree growth. Applying boron during this time stimulates new shoot growth, increases leaf quantity and photosynthetic efficiency, and lays the foundation for summer fruit expansion. The ideal timing is before bud break in early spring or prior to flowering in late spring.

Autumn Application

Autumn, when fruits mature and are harvested, is also a key period for nutrient replenishment and quality enhancement. Boron applied during this phase improves fruit development, firmness, and sweetness, boosting market value. The best time is from post-harvest to before leaf fall.

2. Application Methods

Soil Application

Soil application is the most common method. Boron dosage and type should be determined based on soil tests. Generally, 3–5 kg of borax (50% boron) per mu or 1–2 kg of boric acid (20% boron) per mu is sufficient. Prior to application, deep tillage ensures better dissolution and root absorption.

Foliar Spraying

Foliar spraying offers rapid boron supplementation. Depending on tree growth stages and soil boron levels, apply sprays during early growth and fruit expansion periods, with 7–10-day intervals. Use 0.3%–0.5% boric acid solution or 0.1%–0.2% borax solution.

3. Precautions

Avoid Overapplication

Excessive boron can lead to excessive vegetative growth, reducing fruit quality and yield. Control dosages strictly to prevent overuse.

Balance with Other Nutrients

Fruit trees require balanced nutrients. Combine boron with nitrogen, phosphorus, and potassium to maintain overall nutritional equilibrium.

Consider Soil pH

Boron types vary by soil acidity. Acidic soils benefit from high-boron boric acid, while alkaline soils suit low-boron borax. Test soil pH before selecting the appropriate boron source.

Monitor Pests and Diseases

Overapplication may induce pests or diseases. Regularly inspect trees and address issues promptly.

proper boron use enhances fruit quality and tree health. By timing applications correctly, using suitable methods, and avoiding excess, boron’s benefits are maximized. Pairing boron with complementary nutrients, soil testing, and vigilant pest management ensures thriving trees and economic returns.