Mulberry is propagated mainly through saplings obtained from disease-free nurseries.
When mulberry cuttings are planted in nurseries, several soil borne pathogens cause various diseases. Stem-canker, cutting-rot, collar-rot and die-back are the major nursery diseases, which cause more than 30 per cent mortality of cuttings and saplings in nursery.
Ploughing
For destroying the various soil borne pathogens during summer months, the land selected for nursery preparation should be deeply ploughed and solarised by covering the plots with transparent polythene sheets for about a month.
If soil is infested with nematode/ root rot pathogens soil fumigation should be done with Durofume (Ethylene dibromide + methyl bromide, 1:1) at rate of 9 ml/m.
Application of Organophosphate and Carbamate nematicides like Furadan 3G (Carbofuran) at the rate of 4.0 kg or Rugby 10G (Sebufos) at the rate of 3.0 kg/acre of nursery bed is recommended.
The farm implements used in nursery preparation should be dipped in Kerosene or 5 per cent formaldehyde solution before next use. For avoiding occurrence of soil borne diseases, a bioformulation nursery guard should be applied.
One kg of nursery guard is mixed thoroughly with 60 kg of well-decomposed farmyard manure (sufficient for 2,000 stem cuttings) and added to 10-12 litres of water to maintain the 15-20 per cent moisture.
The mixture is stored under the shade for one week by covering with gunny cloth to enhance the multiplication of trichoderma colony.
It is then broadcasted in nursery beds at the rate of 2 kg/m and incorporated into the soil by light digging before planting the cuttings. Planting material from healthy plots only should be used.
Weed removal
Stem-cuttings should be soaked in 0.2 per cent Dithane M-45 for half an hour before plantation in nursery beds. Weeds around the nursery beds should be periodically removed and properly disposed of.
(Dr. N. B. Chowdary, Scientist, Research Extension Centre sub unit, Central Silk Board, Giddalur – 523357, Prakasam District, Andhra Pradesh and Dr. Ch. Satyanarayana Raju, Scientist, Regional Sericultural Research Station, Central Silk Board, Anantapuramu, Andhra Pradesh, email: recsugid@gmail.com, Mobile: 08520882624.)