In terms of area under cultivation, citrus is the third largest fruit crop, after banana and mango, that is grown in India. Citrus plants include sweet orange, mandarin, sweet lime, kagzi lime and grape fruit. With their sweet and tangy flavor and a wealth of health benefits, citrus fruits are a true gift from nature.
Climatic requirement and soil:
Sweet orange and grape fruit thrive better in low-rainfall sub-tropical climate. If grown in regions with heavy rainfall, sweet orange does not ripen properly with rind remaining green and it also tastes insipid.
Mandarin, lime and lemons prefer humid tropical climate with warmer winters and high rainfall. Extremes of weather and frost are harmful for such trees.
Citrus plants thrive on loamy, well drained soil. A regular potting mixture of equal parts of garden soil and compost with some amount of cocopeat allows roots to grow and spread well. The pH of the soil should remain within 6.0 to 6.5.
Selection of plants:
One should choose varieties of citrus plants such as Kagzi Kalan lemon, Kinnow and Nagpur mandarin, Ducan, Foster and Thompson grape fruit, Mosambi, Pineapple, Malta sweet orange. Grafted varieties start flowering and fruiting much earlier than seed-grown ones. The plants should be free from any disease and have a healthy foliage.
Selection of Container:
Citrus plants grown in ground develop adequate root structure which helps the plant to flourish. In contrast, container plants need specialized care. Young citrus plants should be grown in small containers of about 8 inches since it shall be easier to maintain proper soil moisture and prevent root rot. Two to three year old trees will need a 10 to 12 inch diameter container and eventually a bigger size container for mature tree.
Terracotta, plastic or wooden containers with several drainage holes help in good aeration of the roots.
Placement of Container:
At least 6-7 hours of sunlight is needed for good flowering and fruiting. During scorching summer months, plants can be shifted in semi-shade.
Citrus varieties prefer infrequent, deep watering as opposed to frequent shallow watering. Water when the top layer is dry. The leaves should be showered daily during warm, dry months to maintain humidity. Cool conditions in winter will necessitate less frequent watering than hot, sunny summer conditions.
When the tree starts flowering, reduce the frequency of watering to avoid bud-drop. Watering during this period should be done only when 2-3 inches top layer of soil is dry. After fruiting starts, soil can be kept moist with deep watering as needed.
Fertilizing and Pruning:
Citrus plants need extra nitrogen, so fertilize in spring and after monsoon with manure, kitchen waste compost, vermicompost, leaf mould etc. These slow releasing products will feed the plant over time. Liquid fertilizers and micronutrients may also be added time to time. The pH of soil can be maintained in acidic range by addition of one teaspoonful of tea leaves once a month. Bonemeal and mustard cake powder can be added in small quantities during growing period.
Prune off any new shoots that arise from below the graft union. These are rootstock shoots and won’t grow into the desired citrus variety. Pruning of the tree can be done in early spring to remove errant or leggy branches.
Aphids, scale, and mealybug pests tend to attack the plant. Dabbing mealy bugs with cotton swabs dipped in rubbing alcohol or spraying neem oil periodically helps in controlling them.