Rooftop Gardening of Fruit crops

Dr Akash Sharma
Rooftops in urban spaces are rarely considered with great potential for terrace gardening. Due to non-availability of land for kitchen gardens activities in big cities, people in urban areas frequently want to grow some types of fruit trees with the space available in the terrace.
Fortunately, a wide variety of fruit crops can be grown in containers with some degree of successviz., guava, apple, strawberry, pineapple, papaya, orange, blackcurrant, pummelo, sweet orangeetc. A well planned terrace garden ensures round the year supply of fresh fruits.The main benefit of rooftop fruit farming is to provide local supply of fresh fruits every day.
In the rooftop garden, plant growing structures such as earthen and plastic pot, wooden and concrete bed, drums, large rubber planters and their sizes are major concern to grow different crops. As plant growing structures; plant growing media is also a major concern for sustainable rooftop fruit culture. Plant growing media including Cocopeat, Vermiculite, perlite and soil organic matter such as vermicompost, decomposed cow dung, poultry manure etc. improves the soil structure, aeration, slow release nutrient which support root development leading to higher yield of fruit plants.
Preparation of Potting mixture
Fruit can grow in many types and sizes of containers including wooden, ceramic, metal or plastic tubs, buckets, pots with minimum of more than 1.5 x 1.5 x 1.5 feet (LxBxD). Most fruit plants require a large amount of water, so a sizeable container is necessary to prevent plants from drying out. An inch or two of small stones or gravel in the bottom will aid water drainage. Keep in mind that if soil freezes, pottery containers tend to crack and break.
Growing Media and its Composition
Different Media or Substrates
Coco peat: It is a by-product of the coconut industry and is used widely as a substrate due to its low cost, aeration, drainage and long life. It is advisable to use coco peat after treatment with steam or other means of disinfestation.
Vermiculite: It is an aluminum-iron-magnesium silicate. It is a mica-like mineral which expands to open-flake structures on heating at high temperatures. It also contains important minerals, especially calcium and magnesium besides having a near neutral pH. Vermiculite is a critical desirable component of soil less root substrates because of its high nutrient and water retention and good aeration capacity while bearing a low bulk density.
Perlite: It is a crushed volcanic rock that has been heated and expanded to become a lightweight, white material. Perlite is sterile and has a neutral pH. It improves air space and water drainage of the nursery medium. It can hold about 3-4 times of water equal to its weight in water. Use of perlite keeps the weight of the media lesser in comparison to soil.
Soil: The soil with good water and nutrient holding capacity, having sufficient amount of air and assure proper root growth should be used so that the container and plant do not fall over. Garden soil or commercial top soil can be used if they are amended with peat and either vermiculite or perlite. Soil provides the anchorage to the fruit plants in the container.Soil should be placed as the ¼ portion of the substrate filled just above the stones and gravels in the container.
Regular watering of the polybag nursery is very important to ensure proper growth of fruit plants. The frequency of watering should be adjusted depending upon rainfall and other weather conditions, type of potting mixture used and age of seedling. During periods of high temperature, it may be necessary to water a plant twice or thrice a day. Take care not to overwater; plant roots need air as well as water therefore, drip irrigation is an ideal solution of irrigation for container grown fruit plants. Always test the soil with fingers before watering the fruit plants grown in containers.
Training and Pruning of Container fruits
Training System: Training means developing a desired shape of the tree with particular objectives by controlling habit of growth. Training is start from as soon as the new growth emerges after transplanting of fruit plants in the container. Some fruit crops require training like guava, mango, kinnow, oranges, sweet oranges, lime and lemons etc. Mainframe formation work must be strong. Training is a practice in which tree growth is directed into a desired shape and form. Training young fruit trees is essential for proper tree development. The goal of tree training is to direct tree growth and minimize cutting.
Pruning: With few exceptions, fruit trees will develop and maintain their natural shape with little or no training or pruning. They will occasionally become “leggy” when grown indoors or in poor light for too long. Leggy branches should be partially cut back to force branching and bushiness.Frequently, the top will grow rather large and begin to exceed the capability of the root system. Consequently, some leaf shed and twig dieback will often occur. Such plants should be pruned back heavily to rejuvenate them. When plants are heavily pruned, less fertilizer and water will be necessary to compensate for the reduced plant size.
Manuring: Good nutrition is essential for the success of container-grown fruit trees, but excess fertilizer can result in overgrowth, poor fruiting, and possible dieback due to salt accumulation. The polybags must be irrigated on the same day after the application of fertilizers.The fertilizer should contain nitrogen, phosphorus, and potassium in balanced proportions and should include lesser amounts or traces of magnesium, iron, manganese, zinc and copper. The ingredients and quantities of each nutrient contained are listed on the fertilizer label.
Roof top fruit growing is an way of producing fresh fruits within cities by using unused roof space in buildings. We got low-priced and environmentally friendly fruits which can rapidly increase the food security in urban areas ofJammu Province. Groups of stakeholders andcertain marginal areas of Jammu can be benefited with container growing of fruits. Rooftop farming can help to meetfood demand by supplying fresh and hygienic fruits, reducing household expenditure for buyingcostly fruits, creating a healthy atmosphere by improving air quality and absorbing carbon from the air and lessening the impact of climate change.
(The Author is Associate Professor, SKUAST-Jammu)