Guavas are harvested throughout the year. The fruit matures 90-150 days after flowering. Guava fruits develop best flavour and aroma only when they ripen on tree. In most of the commercial varieties, the stage of fruit ripeness is indicated by the color development which is usually yellow. Ripening of guava starts on the tree and continues even after harvest. It is accelerated in rainy season due to high temperature and slows down in rainy/winter season due to low temperature. During the height of the season, harvest intervals cannot be more than 2 or 3 days. Otherwise, losses in overripe and insect-or disease-damaged fruits can become very severe.

Guava is a delicate fruit requiring careful handling during harvesting and transporting. The fruit is soft and requires considerable care in picking and handling. Although harvesting needs to be mechanized as the industry expands, at the current time harvesting is done by hand using pails for temporary storage of fruits. The fruits are harvested selectively with the stalk and leaves.

Mechanical harvesting trials with a tree shaker are very positive, but there are problems that need to be resolved before mechanical harvesting can become a reality. The type of machine, shaking stroke, proper maintenance of harvest fruits, and ripening of green fruits harvested are some problems that need to be solved.

Once picked, the fruit deteriorates rapidly if left standing in the hot sun in the fields. Filled pails are emptied into lug containers, which in turn are loaded onto trucks to be hauled to the factory. When in the field, they should be stored in a cool location under the trees or in a centralized shed protected from the scorching sun. Good ventilation is necessary to check build up of heat.

However, when overnight storage is necessary, the boxes should be placed in a well-aerated, covered area. Storage overnight in tightly stacked boxes on the truckbed is undesirable since the temperature within the stack of boxes can be higher than the surround air temperature.

For distant markets, wooden or corrugated fiberboard boxes are used along with good cushioning materials-paddy straw, dry grass, guava leaves or rough paper. If feasible, fruits should be hauled to the factory twice a day or as soon after picking as possible.

The fruits should reach the consumer in a firm condition. For local market, fully yellow but firm fruits are harvested, whereas half yellow should be picked for distant markets. The best way to maintain quality is to process the fruits soon after harvest and have the fruit puree immediately chilled, frozen, or aseptically packaged. If necessary, the factory should be run 24 hours a day. An alternative procedure that may be used is to have reefer chill vans in the field to receive the fruits as fast as they are picked. This alternative may be economically unsound now, but efficiency approaching these requirements should be strived for to maintain quality.

Generally, there are 2 crops per year in southern Puerto Rico; the heaviest, with small fruits, in late summer and early fall; another, with larger fruits, in late winter and early spring. In northern India, the main crop ripens in November-February and the fruits are of the best quality. An average winter crop in northern India is about 450 fruits per tree. Trees may bear only 100-300 fruits in the rainy season but the price is higher because of relative scarcity despite the lower quality. Of course, yields vary with the cultivar and cultural treatment. In Egypt guava will be available in late July to April.