Abstract:
A field experiment was conducted to determine the management of tomato late-blight through
host plant resistance and fungicide application at Auyo and Buji during 2019/2020 dry season.
The treatments consists of four tomato varieties (Rio-grande, UC-82B, Roma VF and Rukuta)
and five fungicide (Ridomil-gold) frequencies (0, 1, 2 3 and 4 time spray), the unsprayed plots as
a control and were laid out in a Split Plot Design where variety in the main plots while
treatments (fungicide) in the sub-plots with three replications comprising of sixty (60) plots.The
results were analyzed by ANOVA and the means were separated using Duncan’s Multiple Range
Test. The inoculation of the disease is by natural epiphytotics. Spraying of fungicides started at
the first appearance of the disease and continues according to spray schedule at 10 days interval.
Unsprayed plots were left as control for all varieties. During fungicide sprays, each plot was
shielded with polyethylene sheets 3m high on all sides of the plot to reduce inter-plot
interference, i.e., to prevent the drift effect of the fungicide to the neighbouring plots. The
parameters assessed and collected were; incidence and severity of tomato late blight, days to
50% flowering, days to 50% fruit setting, stand count, number of branches per plant, number of
days to first and last picking of fruits, number of fruits per plant, and yield (t/ha). Integration of
varieties and fungicide spray frequencies significantly reduced late blight epidemics and
increased fruit yield. In both locations, severity was highest on the Rukuta variety and the lowest
on the Rio-grande. The untreated plots of the four varieties were recorded with highest disease
severity, while the lowest were recorded from plots treated with three and four time sprayed.
There was a significant difference between the varieties and fungicide sprayed in both locations.
In conclusion, integrations of varieties and 3-4 times Ridomil-gold sprays were found to be an
effective treatment in reducing tomato late blight epidemics and increasing fruit yield. Thus it is recommended to use this spray level as it gave the highest protection against late blight and the
highest monetary benefit as compared to the other treatments and the control. The interaction
between variety and fungicide sprayed were significantly difference in many parameters and
were not significantly difference in some parameters in both locations. However, based on this
research work, it is recommended to the farmers that for tomato late blight management,
improved varieties should be use and be sprayed 3-4 times with appropriate fungicides for stable
and profitable tomato production in Nigeria. |
