When walnuts grow on trees, they are oval to oblong in shape, about 6-15 cm long and 3-6 cm wide, with a rounded top or sharp or short acuminate top. The base is skewed, approximately round, dark green, and the peel wall is thick.

When the fruit is young, there is a layer of short hair on the green skin. As it matures, the green hair disappears, and many white spots appear on the green skin. As it grows older, the color changes from green to yellow, and then there will be Lots of black spots and gradual cracking.

Extended information:

Most of the walnuts harvested by manual knocking have green peels. Once harvesting begins, the green peels must be removed and dried during harvesting. It is an important measure to ensure the high quality of nuts.

Walnuts with green skin, because the green skin has the properties of heat insulation and preventing moisture loss, the nuts accumulate heat. When the temperature is above 37 degrees, the kernels can easily reach above 40 degrees and be harmed by high temperatures. When harvesting under the hot sun, it is even more necessary to speed up the picking. Walnut peeling, manual peeling is time-consuming and labor-intensive. The following methods are commonly used in production for peeling and cleaning.

1. Pile retting and peeling method: The green fruits should be peeled off immediately in a cool place. When the green skin is not peeled off, they can be stacked in a cool place. Do not expose them to the sun, and then press them about 50 cm apart. Thickness piles upon piles. If you add a 10 cm thick layer of hay or dry leaves to the fruit pile, it can increase the temperature inside the pile, promote fruit ripening, and speed up peeling.

2. Ethephon peeling method: After the fruits are harvested, dip them in an ethephon solution with a concentration of 0.3% to 0.5% for about 30 seconds, and then pile them up to a thickness of about 50 cm in a cool place or in a cool place. Indoors, at a temperature of 30 degrees and a relative humidity of 80% to 90%, the peeling rate will reach over 95% after about 5 days.