Durian biological

Study was conducted from October 2023 to July 2024 on 20 7-year-old Musang King in Vietnam.

Full research report in pdf … Investigation of biological characteristics of Musang King

Presentation paper by Prof. DR. Tran Van Hau on Sept 11st 2025 …

Following are the extractions from the paper, to be practiced in the field ..

…………………………………. End of Research ………………………………………

Rule of thumb to follow …

Calcium moves around the plant in the transpiration stream via the xylem vessels. Calcium will therefore be deposited in plant organs that have the strongest demand for water; this is principally the leaves. New developing leaves are always going to be the strongest sink for calcium. The demand for calcium by the leaves is over 75 times more than the fruit.

Water flow and therefore calcium movement to the developing fruit is a little more complex.

Early fruit development (the first six weeks from fruit set) is the crucial window in which calcium moves into the fruitlets. During early fruit development the surface to volume ratio of the fruit is high. This increases transpiration and helps water to move readily into the fruitlets taking calcium with it. Also, the outermost layer of the young fruitlet’s skin has only a small amount of wax on it. This makes it more permeable to water movement.

Calcium absorption occurs for about six weeks after fruit set. Absorption then levels off and can slightly decline as fruit enlarges through to harvest. This is because there is a dilution effect as the total fruit calcium is now spread over a larger volume of fruit. Unlike other nutrients, like potassium and nitrogen, calcium does not move in the phloem and so will not re-distribute from the leaves to the fruit. Therefore, at this stage, the only way to get more calcium into the fruit is by regularly applying calcium sprays directly to the fruit.

When we look for the best fertilizer in the market with scientifically research proven. Those raw materials utilized for Hydroponics will do the work. These are the cardinal rules …

Urea free
Chloride free
High ratio of Nitrate / Ammonium
Appropriate sulfur content, high Sulfur content may compete with Nitrate
Soluble Phosphorous, instead of Citrate-soluble Phosphorous.
Supplement of calcium is utmost important during application of fertilizer 1-1-1.5