Question

WHAT IF? Apple growers in Japan sometimes make a nonlethal spiral slash around the bark of trees that are destined for removal after the growing season. This practice makes the apples sweeter. Why?

Short answer

Non-lethal spiral slash cutting around the bark of trees is removed after the planting season because this practice leads to the sweetening of apples. The spiral cut decreases the optimal bulk flow of phloem sap to the root sinks, permitting more fluid to move from the source leaves to the fruit sinks and sweeten them.

Step-by-step solution

Sweetening of fruits

Sucrose is naturally present in sugar cane, sugar beets, apples, oranges, carrots, and other fruits and vegetables that lead to a sweet taste.

Photosynthesis, a natural mechanism that converts sunlight into energy, is used by all green plants to make sugars, including glucose and fructose, which the plant converts to sucrose. Fructose, glucose, and sucrose occur naturally in all plants and serve as the foundation for all food energy.

Source and sink phenomena

A plant can be separated into the source and sink sections, with sources being the areas where net carbon dioxide fixation occurs and sinks being the areas where assimilates are stored or consumed.

The phloem transport system connects the plant's essential elements. Pressure flow refers to the process by which sugars are transported from sources to sinks via the phloem. Active transport at the sources transports sugar molecules into the sieve elements (phloem cells).

Spiral slash around the bark of trees is made to form sweeter apples

Farmers form a non-lethal spiral slash around the bark of trees removed at the end of the growing season. Non-lethal spiral slash stops the phloem sap from flowing in quantity to the root.

Phloem sap travels from sugar production locations to sugar use or storage sites. As a result, more phloem sap can flow from the source leaves to the fruit sinks, sweetening them.