Leafing through

Our am is to always update you on the latest. Nowadays you must have noticed the distortions on the leaves of Alstonia tree. See the accompanying picture. The leaves are blistered. This is due to the attack of gall insect. The insect damages the leaves from the back and makes a house for it by making a gall. It feeds from within. It is not easy to control as it is well protected. To control it in time,spray rogor/metasystox dissolved at one milliliter to a liter of water. Spray from the down side of the leaves too. Repeat the spray after a week or 10 days.

* I find some black coloured insects at the buds of my chrysanthemum plants. What kind of insect is this? How can I control it? What kind of damage does it cause?
Parneet Kaur,Chandigarh
The insect that you have seen is aphid. It sucks sap from the terminals thus weakening the buds. As the blooms open they enter the folds of the petals and suck sap thereby shortening the bloom life. Spray rogor,dissolved at one milliliter to a liter of water. Repeat after a week.

* There are some wavy lines on my nasturtium plants and also on some dahlia leaves. What kind of disease is this and what’s the remedy? The leaves seem to sag.
Parmajit Singh,Mohali
The lines you have seen are the damaged trail of leaf miner insect. It feeds under the parchment like structure and thus is not affected by common sprays. For this,spray systemic chemicals like rogor or metasystox,dissolved at one milliliter to a liter of water.

* After how many days can I pluck red radish. I planted it about 28 days back.
Savita,Chandigarh
Be ready to pluck them after about a week or so. They should be ready by then

* How much fertilizer should I add to my mango plant? It is an Amarpali
Kulbir Singh,Chandigarh
To recommend the amount of fertilizer,I’ll have to know the age of the mango tree!

ASK DR GREEN at satishnarula@yahoo.co.in