Abstract

                                Studies to assess the effects of intercropping in tomato under irrigated and rainfed conditions for the management of key pests at Regional Research Station, Paiyur, TamilNadu. Agricultural University, TamilNadu during 1998-2000. Experiments were conducted in a factorial randomized block design using intercrops viz, clusterbean, green gram and mustard and two rounds. of spraying with NSKE 5% and monocrotophos 0.07%, once on 30th day after transplanting and second at the time of maximum flowering and fruit set. The results revealed that tomato intercropped with mustard at 2:1 ratio had recorded reduced incidence of whitefly and thrips population and fruit borer damage as well in two different field studies. Natural incidence of tomato spotted wilt virus (TSWV) and leaf curl virus (LCV) diseases. were noticed on the rainfed tomato crop raised during August-September, 1999 planting season. The incidence of TSWV and LCV diseases were less under intercropped tomatoes than sole crop tomato and this was significantly low on the mustard intercropped plots. Nearly 30% of plants were lost due to these diseases in the tomato sole crop plots and this loss in plant population was nearly 45-60% more than the mustard intercropped plots. The combined yield of undamaged and damaged fruits was 16.319 t ha and 16.028 t ha for the sole tomato and mustard intercropped tomato under irrigated condition. However, under rainfed condition due to the severe incidence of viral diseases, an yield of 5.832 tha was recorded in sole crop while it was 8.527 t ha in mustard intercropped plots. The undamaged fruit yield recorded was 15.00 and 7.810 tha for the mustard intercropped plots, whereas it was 13.386 and 4.833 t ha for sole crop tomato under irrigated and rainfed conditions respectively. The mustard intercropping had given an additional net return of Rs.7080 and Rs.12400 because of reduced pest infestation under irrigated and rainfed conditions respectively.

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