Specialty vegetable crops

Cultivation Environment

l  Dragon Fruit is a tropical and subtropical fruit, prefers sunlight and fertile soil, but is tolerant of cloudy, dry and hot weather, and infertile soil.   

l  Optimal growing temperature is between 25^oC and 32^oC.  Temperature falling below 5^oC causes serious damage.  Protective measures, such as covering with plastic layers, should be taken when air temperature drops to 10^oC. 

l  Dragon Fruit is not demanding on soil quality, but prefers sandy loam with rich organic matter and good soil aeration property. 

l Optimal soil moisture content is between 60% and 80%.  Sandy loam with a pH value between 5.5 and 7.5 is preferable.  Good soil aeration is required.  Soil that is too sticky may hinder the growth of roots. 

Planting and Spacing

l  There are two methods of cultivation, i.e. trellis-climbing method and post-climbing method.  The post-climbing method is more commonly adopted due to lower production cost and higher land utilisation. 

l  Plant spacing for the trellis-climbing method: 2.5 m x 2.5 m.  3 – 4 seedlings can be planted on each post. 

l  For the post-climbing method, row and plant spacing are 3.2 m and 2.8 m respectively.  3 – 4 seedlings can be planted on each post. 

Fertiliser Application and Management

Basal Dressing: Apply 10 – 15 kg of mature compost, 3 - 5 kg of both peanut cake and bone meal to each post, blend the mixture well before planting the seedlings on it.  

Top Dressing:    1.   After planting, apply top dressing (mainly nitrogenous fertiliser,  

                                 preferably liquid fertiliser made of peanut cake) every 10 – 15 days. 

                           2.  As the plant begins to fruit, apply 0.5 kg of organic fertiliser (N:P:K = 

                                4:2:10), 0.5 kg of both peanut cake and bone meal to each post. 

                          3.   After harvest, apply 0.5 kg of organic fertiliser (N:P:K: MgO =               

                               4:3:3:1)  and 1 kg of peanut cake to each post.               

Irrigation:  While dragon fruit is drought tolerant, irrigation is still necessary.  Its roots are  s

                   hallow and spread widely in topsoil (5 – 15 cm deep in topsoil).  The surface

                   soil must remain moist throughout the year to maintain vitality of the roots.

                   Dragon fruit’s roots cannot stand immersion in water, and prone to damage if

                   immersed in water for 24 hours; in severe case, the plant may wither. 

Plant Adjustment

l  Before the succulent stem reaches the top of the post, keep only one leader stem and prune away all the branches, so as to stimulate growth of the succulent stem and enhance fruiting quality. 

l  When the leader stem grows over the top of the support post, prune away its tip, allow

    lateral buds to grow into branch stems, keep three or more branches that lay on the

    support ring or trellis at the top of the post, so that they grow into fruiting branches. 

   Allow the branches to hang down naturally to accumulate nutrients for early flowering

    and fruiting. 

l  After the plant has reached the fruiting stage, keep 2/3 of the branches as fruiting branches, nip off the flower buds of other branches, and reduce the growth angles of the branches to promote accumulation of nutrient, so that they will grow into strong fruiting branches.

l  The fruiting branches need to hang down.  When they grow to about 90 cm – 120 cm

    long, prune away their tips so that they will flower.  Only after their tips have been

    pruned away will the branches grow to be strong enough for supporting large fruits. 

l  After harvest each year, prune away branches that have withered after fruiting and those

    that have reached the ground or are shaded by others, in order to stimulate growth of new

    branches, thereby ensuring the fruiting volume in the following year. 

Harvesting

l  Harvest period: 25 – 28 days after the flowers have closed, 5 – 7 days after the skins of the fruits have started to turn red, when the fruits become bright red and the succulent scales begin to soften, with wrinkles or minor cracks forming at the tips of the fruits, the fruits can be harvested. We suggest that fruits are consumed as soon as possible after they are harvested. 

l  Fruits ripen in 40 – 50 days after flowering.  When wrinkles or minor cracks form at the

    tip of the fruits, and the scales on the fruits become shorter and lighten in colour, the

    fruits can be harvested.  It takes about 5 – 6 days to harvest all fruits of the same batch of

    flowers.