THE EFFECT OF APHIDS ON TOMATO PRODUCTION.
REG.NO A138\10138\2007.
THOMAS EZRON OGANDA.
SUPERVISOR DR: MAINA MUIRU.
INTRODUCTION
1 .Tomato production in Kenya
In Kenya tomato producing areas are mainly,
Kirinyaga,Murang’a, Nyeri and Kiambu.
They are mainly grown for local consumption as fresh or
processed products and as an export crop.
2. Economic importance of tomatoes
They are cooked as fresh vegetable or used for making source
or eaten as a salad.
They contain vitamin A and C.
They fetch ready cash to farmers and traders.
Source of employment/income.
For medicinal purposes e.g. lycopersicon is used to treat heart
diseases
3. Constraints in tomato production
Diseases e.g. tomato blight, early blight an bacterial wilt
Weeds, they compete for nutrients, they harbor pests and act
as alternative host and diseases
Non biotic factors e.g. low prices due to low quality fruits and
marketing problems and poor storage facilities.
Natural calamities e.g. heavy rainfall and sudden environmental
changes.
Insects e.g. grass hoppers, crickets, aphids and wire worms.
4. Problem statement and justification
Aphid are quite devastating if no steps are taken to control them,
this has affected commercial production of tomatoes in areas of
high relative humidity. It is therefore necessary to conduct a
research to verify the effect of aphid s on the total productivity of
tomatoes and sect the best control method that can ensure
optimum yields.
OBJECTIVE.
To determine the efficacy of biocatch on aphid on tomato
plants
To determine the effect of the product(biocatch on yield of
tomatoes when applied at different rates).
MATERIALS AND METHODS
Location, the trial was carried out at the field station in the
college of Agriculture and Veterinary sciences, Upper Kabete
Campus, University of Nairobi.
Crop establishment Certified tomato seeds of Roma variety
were sown in a nursery where the seedlings were nurtured for
four weeks and maintained free from pests and diseases. Plots
measuring 4m x 3m were prepared and Diammonium Phosphate
(D.A.P) fertilizer added at a rate of 5g per hill.
Five plants per treatment were randomly selected for data
collection
Treatment effects were assessed by analysis of variance
(ANOVA) using Gens tat 8.1 Release, while least significant
difference (LSD) test was used to compare treatment means.
The seedlings were then transplanted at a spacing of 90cm x
60cm to give a population of 30 plants per plot. The treatments
were the four concentrations of the test chemical applied at the
rate of 2.5kg, 3.75kg, 5kg, and 6.25kg/ha. The standard chemical
check (Nimbecidine) was applied at the rate of 1.5L/Ha and the
negative control (Water), making a total of six treatments. These
treatments were arranged in a randomized complete block design
with four replicates.
The four concentrations of the test chemicals namely 2.5kg,
3.75kg, 5kg, and 6.25kg/ha were evaluated. These rates
translated to 15g, 22.5g, 30g and 37.5g respectively dissolved in
6.0liters of water for each treatment. The standard Nimbecidine
was applied at the rate of 1.5lt/ha, which was translated to 9ml
dissolved in 6 liters of water and six liters of tap water, was used
as the negative control.
Pest Assessment, Three leaves from each of the sampled plant
were obtained from the bottom, middle and top part of the plant
and used to determine aphid population. In cases of heavy
infestation, the leaves were subdivided into sections and aphids,
were counted from one section and the total number of aphids
worked out for all the sections.
RESULTS
The aphid population in tomatoes was significantly different (P
 0.05) among treatments and sampling periods (Table 1,
Appendix, 8.1).
The highest reduction in aphid population occurred when
6.25kg/ha Bio-Catch was applied while the least was observed at
2.5kg/ha level. Bio-Catch at the rates of 3.75kg/ha was more
effective in aphid management compared to that of 2.5kg in the
second, third and fourth samplings.
Efficacy against aphids
Table 1. Mean counts of aphids after application of different treatments
Treatment
Applicat
ion
Rate
Bio-Catch
2.5kg/ha
Bio-Catch
3.75kg/h
a
5kg/ha
6.25kg/h
a
2.5kg/ha
Bio-Catch
Bio-Catch
Nimbecidine
Negative
control
CV%(P0.05)
Lsd
Pretreatme
nt
Populat
ion
95.5
1
2
Sampling period
3
4
5
6
29.8b
95.9
15.8 38.7b
b
11.0b 22.6c
21.8c
10.6 31.3
b
b
5.3bc 4.9c
82.7
3.9bc 14.3d
22.0c
1.8c
1.9c
83.6
2.7c
22.1c
0.8c
1.7c
44.1a
b
37.3
b
50.7a
83.6
2.2c
0.9c
0.9c
7c
83.6
68.0a 97.4a
26.5b
c
128.4
a
12.9
7.11
15.7c
d
9.3d
46.6a
97.8a 214.9 46.6a
a
Effect on tomato yield.
The yield increase over time was highly significant (P 
0.05) (Appendix 8.2). The yields from the third harvest
were significantly (P  0.05) different from other harvests
(Table 2). Plants treated with Bio-Catch at the rate of
5kg/ha gave the highest yields while plants from the
negative control yielded the least. However there was no
significant difference (P  0.05) in yield from the different
treatments
Table2. Mean tomato yield at different times of harvesting
Time of Harvesting
Mean
1
353.66b
2
360.17b
3
808.05a
4
427.23b
5
433.75b
CV (P  0.05)
1.988
LSD
112.97
DISCUSSION
The results of the trial showed that Bio-Catch (Verticillium lecanii
1.5%) was effective in the management of aphids. Bio-Catch
effectively controlled aphids on young plants that produced
enough flush, a requirement for the development and
reproduction of these pests. This molecule has a great potential
to control the pest and would be of great benefit to the farmers.
Bio-Catch applied at the rates of 5.0 and 6.25kg/ha was
comparable in efficacy in all the sampling periods apart from the
second and 6th samplings where the latter was more effective.
CONCLUSIONS AND RECOMMENDATION
Bio-Catch can be recommended for the effective control of aphids
at the rate of 5.0kg/ha.
Repeated sprays can be applied up to three times against aphids
whenever they reach the threshold levels till the population is
brought below the economic injury level.
THANK YOU.