Bags protect fruits before harvest

Post-harvest activities


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Protect fruit from pests while the fruit is still on the tree or vine by covering it with a bag. Some examples are given of farmers using this technique in the Philippines, the Republic of China, and the People’s Republic of China, for protecting guavas, peaches, bananas, and grapes.

HOST: Do you have problems with pests attacking your fruit? Many farmers deal with this problem by spraying expensive, poisonous chemicals on their fruit. However, some farmers in Asia use quite a different method that is very effective and may be less expensive. They cover each individual fruit or bunch of fruit with a bag or sack. Some even use loosely woven baskets made from coconut fronds. They do this soon after the fruit has formed and is still on the tree or vine. This protects the fruit from being attacked by insects and diseases, and even from birds. The bag also protects fruit from other kinds of damage when it is being harvested and transported.

Of course, it takes quite a bit of time and effort to use this method, but farmers who do say that it is worth it. Some of them also find that their customers will pay a higher price for fruit that has been protected this way.

Farmers use bags on some vegetable vine crops, on mangos, papayas, jackfruit, guavas, bananas, and grapes. Some of the coverings commonly used are paper, including newspaper, jute sacks, and plastic bags. If you use plastic bags, you might want to punch a few small holes in the bags to allow air to circulate. Perhaps you wish to try this method yourself.

If you decide to try this, you may be able to buy the bags or you could make them yourself. They should close at the top, but be sure they are big enough to cover each fruit, or bunch of fruit, completely. They should also be big enough to allow for proper growth of the fruit inside them. For example, to cover a bunch of bananas, you might want to try using a big jute sack.

Cover your fruit soon after it has formed or at least a month before it ripens. Here are a few examples of how some farmers use this method.

Elly Piano in the Philippines noticed that fruit flies were damaging his guava fruits. He tried covering them with plastic bags to protect them and had no more trouble with fruit flies. He also wraps bitter gourds in newspaper while they’re still on the vine to prevent insect damage.

At Long Quan in Sichuan Province of the People’s Republic of China, farmers protect their peaches from insects with homemade paper envelopes. They put one on each peach left on the tree after thinning, when the peaches are about 2 1/2 centimetres (1 inch) in diameter. They discard the paper at harvest time.
In Che Che Township, Republic of China, Lin Chen Chen ripens his bananas in blue plastic bags. He ties a bag over each bunch after it has formed. He produces beautiful bananas this way.

In Tachun township, also in the Republic of China, grapes are protected from insects and mildew in specially treated paper bags. Each bag has a printed message and the grower’s trademark on it, and the farmers leave them on the bunches of grapes when they harvest them. They get very good prices for their high quality grapes with each bunch individually wrapped like this.

Special note
The following suggestions are from “Bagging Young Fruit,” in the Agroforestry Technology Information Kit produced by the International Institute of Rural Reconstruction, Silang, Cavite, Philippines. They provide information on the times at which bags should be applied to fruit on the trees. Depending on the types of fruits grown by the farmers you serve, you might include one or more of them in the information you pass on to them.
Mango – 10-15 days after the time when you first see fruit starting to form

Jackfruit – when fruit is the size of your fist
Banana – as soon as the male blossom is removed
Cacao – when fruit or pods are at least 4 to 6 centimetres (2 inches) long
Guava – when you first see fruit starting to form

Information sources
1. Interview recorded by Jennifer Pittet with Mr. Eusebio T. Imperial, Program Associate, The International Institute of Rural Reconstruction, Silang, Cavite, Philippines.
2. “Bagging of young fruits,” in the Agroforestry Technology Information Kit, 1989, International Institute of Rural Reconstruction, Silang, Cavite, Philippines.
3. Interview recorded by Jennifer Pittet with Elly Piano, farmer, Philippines, re. the use of bags on guava and bitter gourds for preventing insect damage.
4. Interview recorded by George Atkins with Madam Xiong Zhi Lin, Chief Agronomist, Agricultural Management Office, Science and Technology Commission of Chengdu, Chengdu, Sichuan, People’s Republic of China, re. homemade paper envelopes for protecting peaches on the tree.
5. Interview by George Atkins with Lin Chen Chen, Che Che Township, Republic of China, re. blue plastic bags for protecting bananas on the tree.
6. Interview by George Atkins with member of Tachun Farmers Association, Republic of China, re. paper bags for protecting and marketing high quality grapes.