Association of plant parasitic nematodes in cultivated crops results in heavy yield losses. In recent years, nematode problems in tree fruit crops are great concerns to the farmers due to the economic loss caused by nematodes and the associated fungal pathogens.
Although effective biocontrol agents like Paecilomyces lilacinus, Pochonia chlamydosporia, Pasteuria penetrans and Mycorrhizae are available as commercial formulations to manage the nematodes, there are some bottle necks for these bioagents to reach the target sites, the roots. In fruit tress generally the roots are at a depth of about 2-2½ feet and whatever inputs we give, they hardly reach the target site making nematode control a difficult task.
Subsoil root drenching is a simple technique to make the inputs to reach the roots we can get a good control of nematodes. PVC pipes of 2½ feet length and ¾ inch dia is taken. A half feet of the pipe is perforated and buried in soil in such a manner that only ½ foot is above the soil, by making hole with a crow bar.
Three such pipes can be buried around the tree 2 feet away from the trunk. All the inputs can be applied in to the pipe and they easily reach the root zone, the target site. It is a low cost affair as the cost per tree is only around Rs.10-12 and the benefits are many fold. If drip system is already installed in the field, we can make a notch on the top of the pipe and the dripper is seated on the pipe so that the water is also reach the root zone easily.
By using this sub soil drenching technique we can reduce the weed growth to a considerable extent.
Dr. M. Sivakumar, Professor, Department of Nematology, Tamil Nadu Agricultural University tried this technique in pomegranate and found successful in managing nematodes, Dr. S. Subramanian, Head of the department of Nematology told that the inputs we apply for the nematode control for fruit trees hardly reaches the roots and it is the major reason for the increase in nematode population. This practicable technique can be followed wherever feasible to get more benefits.
Dr. K. Ramaraju, Director, Centre for Plant Protection studies suggested that the same technique can be tried in larger areas and in various crops, so that we can have effective control of root pathogens, soil insects in addition to nematodes. He also suggested that the scientists of the Department of Nematology can work on this kind of effective low cost technologies and fool proof recommendations may be given to the farming community.