2of the Department of Entomology.
3Nematology Division, Indian Agricultural Research Institute, New Delhi-12.
Punjab Agricultural University, Ludhiana
1Contribution No. 2/74 of Department of Entomology, based on M. Sc. thesis submitted by the junior author to the Punjab Agricultural University, Ludhiana.
The effectiveness of three common nematocides was studied for the control of the root-knot nematode (Meloidogyne incognita) by first screening on potted (brinjal plants and then testing the promising chemical doses combination on brinjal and tomato in the field. In the pot experiment, the treatments tested were D-D mixture (100 per cent) at 112.33, 168.50, 224.66 280.82 and 336.99 L AI/ha as pre-plant soil injection, DBCP (Nemagon 60 per cent) at 6.73, 13.46, 20.19, 26.92 and 33.65 L AI/ha as post-plant soil drench followed by irrigation; and phorate (Thimet 10 per cent granules) at 1.24, 2.47, 3.70, 4.94 and 7.41 kg AI/ha applied by broadcasting in final stages of preparatory tillage. On the basis of larval population and galling index, the three higher doses of D-D mixture and DBCP, and the three middle doses of phorate were selected for the field tests.
In the field trials, the medium and high doses of D-D mixture and DBCP and the high dose of phorate resulted in significantly lower larval population and root-knot index than in control. Among these, D-D mixture at 280.82 L and DBCP at 26.92 L were found to be the best, considering the larval population on different dates. These were followed by phorate at 4.94 kg, D-D mixture at 224.66 L and DBCP at 20.19 L in the order of decreasing effectiveness. On the basis of root-knot index, D-D mixture at 280.82 L proved superior to DBCP at 29.19 L and phorate at 4.94 kg on both the crops, than D-D mixture at 224.66 L on brinjal and as compared with DBCP at 26.92 L on tomato.
Considering the overall effectiveness on the basis of larval population and root-knot index on the two crops, the effective treatments in the order of decreasing effectiveness were as follows: D-D mixture at 280.82 L. DBCP at 26.92 L, phorate at 4.94 kg, D-D mixture at 224.66 L, and DBCP at 20.19 L AI/ha.
