It is that time of the year when your plants are vulnerable...
Once a visitor to my nursery asked me which is the best fertiliser for my plants and I replied…The dust of your feet. Visit your plants regularly and they will talk to you, tell you what is deficient and what disease they are suffering from! They will also tell you what insect is gnawing at them. Stand near it, look at it and you will know about it, after some experience. And we will help you explore it!
You may have casually seen some black ants moving about on your plant. Did you ever think what their interest was? Now, look for an insect, the aphid, and you will surely find them aplenty, mostly on the terminal growing parts of the plants. So, you thought the ants came to hunt for them? No. And don’t be surprised if I told you that these insect nymphs are their dairy ‘cows’. They are always vigilant to protect them and in case of an emergency, they even pick and carry them gently to a safer place! At merry times, these ants gently rub their antenna on the soft-bodied insects, which in turn ooze out ‘honeydew’ that the ants relish.
But why to talk about ants and aphids now? Because this is the time of the year when they appear in large numbers on almost all the plant species, be it the crop plants, fruit plants, vegetables, ornamentals or seasonal flowering plants.
The users of the two-wheelers are more familiar with this insect, the adults of which become airborne when wind swept and fall into the exposed eyes of the driver during this period! This is the time of the year when they lay eggs to multiply in large numbers, but nature has its own interesting ways. There appear Ladybird beetles, the predators, which devour on their young ones with magical hunger. An adult can eat about 50 aphid nymphs in a day! And then there is competition, a fight for survival. Seeing the mass massacre, the adult aphids start giving birth to young ones straight, bypassing the egg-laying process. They are in such large numbers that they considerably damage the plant by sucking the sap and devitalising them. There is curling of leaves and even the fruits get out of shape.
Another glaring symptom that appears on the plants is blackening of the leaves on either side. This is due to the oozing honeydew from the aphid nymphs that invite all kinds of moulds. These cut of the photosynthesis area of the leaves and thus harm the plant. To control aphids and sooty mould, you can spray rogor and blitox mixed together, at one-and-a-half ml and two-and-a-half gram to a litre of water, respectively. Mix with it a small amount of sticker that is also available at pesticide shops. Repeat the spray after a week to 10 days.
(The author is a Chandigarh-based horticulturist. He retired from Punjab Agriculture University)
