EVALUATION OF LAMBDA STAR IN THE CONTROL OF APHIDS ON KALE. BY JOSPHINE W. NJOGU REG NO.A138/10309/2007
1.0 INTRODUCTION: Kale production in Kenya. Kale (Brassica Oleracea) is one of the most leaf vegetable Its biennial cultivated as annuals. It is a good source of vitamin A, B and C
Introduction cont kales generate both rural and urban employment and income of farmers. Average yield is about 16 to 20 tonnes per hectare. (HCDA, Report 2000). In Kenya,kale is eaten with ugali as well as a fodder crop for livestock. Varieties grown in Kenya are: thousand headed, marrow stem, and collard.
Kales Kales are grown all over the country with highest production in Central, E. and W. provinces. Kale grows well in warm wet areas with altitude range between 2100 m.a s. l. The soils should be loamy, clay, sandy soils and ph range between 5.5 to 7.5
Constraints of kale production. Production techniques and production inputs are lacking. pests attack brassica eg, diamond back month (plutella xylostella), Cabbage aphids (Brevicoryne brassicae, Diseases include: black rot, black leg, ring spot.
1.4 Objectives. 1.To evaluate the efficiency of lambda star.(cyhalothrin 5% EC) in the control of aphids in kale 2. To determine the effective rate of application of lamda star (cyhalothrin 5%E.C)in the control of aphids in kale.
3.0 Materials and methods The study was conducted at the field station of the college of Agriculture and Veterinary sciences, Upper Kabete Campus, University of Nairobi Land was dug and small plots of 1.0 1.0 m were prepared and D.A.P fertilizer was used during planting,
Material cont The treatments were; three concentrations of the test chemical, namely 250, 500 and 1000 lt/ha and the water making a total of four treatments. These rates translated to 0.25,0.5 and 1.0ml respectively dissolved in 1.0 liters. pre-treatment data was taken before the commencement of the treatment application. Four plants per treatment were selected randomly for data collection.
Material cont. The research experiment was laid out in a randomized block design with four treatments. Each treatment was replicated three times making a total of 12 plots
Pest counting Aphids on kales Three leaves from each of the 4 sampled plants were obtained form the top, middle and bottom part of the plant and used to determine aphid population. Incase of heavy infestation, the leaf was subdivided into sections and aphids counted from one section and the total number of aphids was then worked out for all the sections.
Phytotoxicity observation After 24 hour of application the crop was observed to determine Phytotoxicity Indices used were leaf injury on tips and surface necrosis, vein clearing and wilting.
Data analysis Data was analyzed using genstat software and treatment effects were assessed. mean were separated using Least Significant Difference (LSD).
Result Effect of lambda star on aphids counting There were differences observed in the population of the aphids following application of Lambda star in kale The highest reduction in aphid s population occurred when 0.5lt/ha of Lambda star was applied. The experiment results shows that the two rates i.e. 500 and 1000ml/ha were the same in effect in all the sampling The rates of 1000ml/ha had low pest numbers in all the counting.
Table.1 Mean aphids number after application of Lambda star Chemical and rate Pre-treatment population Post treatment population Ist counting 2 nd counting 3 rd counting Lambdar star 250ml/ha 140 34b 29.0b 29.1b Lambdar star 500ml/ha 189 21cd 10.7c 9.7c Lambdar star 1000ml/ha 862 16.5c 7.1c 4.8c Water 369 147a 145.4a 178.8a CV 63.2 LSD 15.5
4.2 Effect of lambda stars on yield of kale There were increases in yields of kales when lambda star were applied. The higher rates namely 0.5 and 1.0 did not differ significantly with respect to increase with increases in yield no significant difference was observed between the lower rates and the plot treated with water
Mean yield of kale the various treatments Treatmen t chemical rates Yield (g/ plant) T2 Lambda star 250ml/ha 411a T3 Lambda star 500ml/ha 808b T4 Lambda star 1000ml/ha 862b TC control Water 369a lsd 297.1
Phytotoxic There was slight leaf burn which indicated slight phytotoxicity. vein clearing and wilting was observed during the trial period hence phytotoxic.
5.0 Discussion Lambda star when applied in kales killed the aphids and reduced their number it can be said to be effective in controlling aphid in kales. higher rates had some burn on the soft part of the plant. Higher rates can cause more environmental pollution and be health hazard to animals and human being.
CONCLUSIONS AND RECOMMENDATION Lambda star was able to control aphids on kale Treatment three was good as the higher rates shows some slight burn on kales and can result in more environmental pollution
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