The Southwest monsoon rains are receding and dry days are ahead of us during the short ‘Indian Summer’ month of October.
Caterpillars are already devouring the leaves of limes and lemon trees as we prepare to give the plants the bahar treatment to induce flowering and fruiting.
Many a gardener unnecessarily kills the leaf-eating caterpillars when actually they are doing him a service free of cost!
The number of leaves has to be reduced anyway to change the citrus plants from the vegetative phase induced by the rains to the reproductive phase at the end of the monsoons.
WHAT IT’S ALL ABOUT
After the monsoons, plants can be disciplined to flower when we want the flowers, subject to the environmental conditions and our needs.
In jasmine, citrus fruits and guava, it is known as the ‘bahar’ treatment for flower induction.
The ‘phoolon ka bahar’ is what gives the name to the treatment. It is used commercially to get a good crop of guavas in winter, and of lemons in winter and summer when they fetch the maximum price because of the high demand.
The caterpillars of the Swallow Tails and Common Mormon may look like bird shit on leaves, but the adults are a sight to behold. The appearance of the caterpillars is actually a camouflage to protect them from insect-eating birds.
They are a common sight these days on the leaves of lime and lemon plants as also on kumquats and bael, or wood apple trees. The host range is across the Rutaceae family.
HOW IT WORKS
The bahar treatment in citrus plants consists of water stress and pruning. The soil is dug up lightly and allowed to dry below the citrus plants till the leaves begin curling up.
Dead and dying branches are cut and removed along with succulent ‘water sprouts’ and any shoots that may emerge from the wild rootstock on which the lime or lemon has been budded or grafted. This is called pruning.
Together, the denial of water and the pruning induce stress in the plant. At this point, the tree is manured with a mixture containing nitrogen, phosphorus and potassium and irrigated generously with water.
All the cut ends are treated with any free copper compound like the Bordeaux mixture or Copper Oxy Chloride (available under trade names such as Bordo, Blitox, Fytolan, Nag Copper, Blue Copper, etc) to prevent die-back disease.
All you need to do is make a slurry of the powder and apply with a watercolour paint brush or any soft bristled tooth brush. The bottom half metre of the tree trunk, just above the ground, is also painted with the copper compound.
Copper is a very important nutrient in citrus plants and the fungicide provides it to the plant.
Prune again in the last week of February for flowers at Shigmo time and fruits during the summer season that follows. Remember that citrus plants love sunshine, so grow them in full sunlight to keep them healthy and to give you lots of limes and lemons during summer to quench your thirst with limboo paani, lime cordial or lemon squash.
The author is a former Chairman of the GCCI Agriculture Committee, CEO of Planter's Choice Pvt Ltd, Additional Director of OFAI and Garden Superintendent of Goa University, and has edited 18 books for Goa & Konkan