Harvesting and Storage Methods for Chestnut Cultivation

Chestnuts have begun to hit the market, and farmers often encounter weight loss, sprouting and severe rotting and deterioration during transportation and storage due to improper management. The following introduces chestnut harvesting and storage techniques for fruit growers' reference.

Timely harvesting

Harvest period: the earliest-maturing chestnut varieties generally mature in late August, and the latest-maturing varieties mature around late October. Most varieties mature in mid-to-late September. Harvesting should be carried out after the chestnuts are fully mature, when the chestnut skin is bright in color, low in water content, high in various nutrient contents, good in quality, and resistant to storage and transportation.

Timely harvesting: when the chestnut burrs turn from green to yellow and split open on their own, and the nuts are brown, harvest when 1/3 of the burrs on the whole tree have split. It should not be too early. It is best to harvest after several consecutive sunny days, avoiding rainy days, otherwise it is easy to cause rotting.

Treatment before storage

Sweating and heat dissipation: freshly harvested chestnut fruits have high temperature, much water, and strong respiration intensity, and must not be piled up in large concentrated heaps, otherwise they are prone to heating and rotting. The burrs should be piled in a higher, cool, and ventilated place, with a pile height not exceeding 1 m. To prevent heating, do not press the burrs tightly, and do not expose them directly to the sun. Weeds and other materials can be covered on top to achieve the purpose of cooling and moisturizing. After piling for about 10 days, take out the chestnut fruits from the burrs, remove diseased and insect-damaged fruits, and dry them in the shade for 2-3 days before storage and transportation.

Fumigation for insect control: after bagging the chestnuts, place them indoors, and use 1.5-2 kg of carbon disulfide per 50 sq m for fumigation to kill insects. Pour the carbon disulfide into a shallow vessel with a large surface area and place it on top of the chestnut bags, allowing the vaporized carbon disulfide gas to disperse into every corner. Close the doors and windows tightly, and seal the gaps of doors and windows with paper. The pests can be killed in 1-2 days.

Preventing sprouting: soaking the fruits in 100 ppm daminozide, 1000 ppm maleic hydrazide, and 1000 ppm naphthaleneacetic acid can inhibit chestnut fruit sprouting.

Chestnut storage techniques

Sand storage method: on the floor of a cool indoor space, spread a layer of straw or sorghum stalks, then spread 7 cm thick fine sand. The moisture of the sand is suitable when it cannot be formed into a ball by squeezing with the hand. Then add chestnuts and wet sand in layers, one layer of chestnuts and one layer of sand, with a ratio of about one part chestnuts to two parts wet sand. The thickness of the sand storage is about 80 cm, covered with straw on top. Where there is no wet sand, rice husk or sawdust can be used instead of wet sand, but attention should be paid to temperature and humidity.

Low-temperature storage and transportation: when the temperature is high after chestnut harvest, they can be stored in a cold storage, and transported to various places after the temperature drops. When placed in cold storage, the chestnuts should be packed in wet gunny bags, the storage temperature should be 0-2 degrees C, the relative humidity about 90 percent, and there should be certain ventilation conditions, with humid cold air passing through.