The Early Bearing and High Yield of Sweet Orange ( Citrus SinensisOsbeck) on Red Loam in Guangdong, China

Abstract

Citrus culture in Guangdong Province is renowned for its traditional method of close planting of 1,200-1,500 trees per hectare, its early fruiting in the third year following planting and its high yield. After about 15 years when the trees decline, they are cut down and the land is planted with other crops. In order to harvest the highest possible yield within this period, the growers have developed a series of unique cultural methods. The present paper aims at introducing the early bearing and high yield of sweet oranges in the hilly red loam regions of Guangdong.

For the purpose of early bearing, the taproot must be trained not to penetrate too deep and feeder root development must be encouraged. Adopting the method of temporary planting nursery trees, cutting back the overgrowth of lateral roots outside the tree canopy and applying manure inside will render the feeder roots to spread wide and deep. And resorting to repeated nipping off of the new shoots to promote a spontaneous and simultaneous outburst of fall flushes from the compound buds will help to form numerous parent fruiting shoots and a well-balanced solid framework. This is a prolific and productive tree management system worked out in Guangdong which results in dwarf scaffold with many branches and a thick green canopy. Subsequently, girdling is used to promote flowering and to prevent fruit drop. Fruit bearing is encouraged in order to surpress vegetative growth and heading back pruning is adopted to prevent premature filling up between the rows of oranges. Although these measures entail much labor, they may pay back with higher economic benefit.