Larvicidal and adulticidal effects of P. guajava oil against T. granarium The effects of varying levels of P. guajava leaf oil on mean percentage mortality of T. granarium larvae and adults are shown in Table 1. No dead larvae and adults of the insect were found in the controls at 1 and 2 DAT. It was observed that low dosage (0.2 ml) of guava leaf oil had no insecticidal effect on larvae at 1 and 2 DAT. However, a highly significant difference (p<0.05) in larval mortality was noticed between the lowest and other rates of treatment. The seeds treated with the oil had varied mean percentage mortality of both larvae and adults which differed significantly (p<0.05) when compared with the mortality recorded in the lowest rate of treatment. The seeds treated with 0.4 and 0.5 ml of the oil had significantly higher (p<0.05) larval mortality (40.0%) than 0.3 ml (20.0%) at 1 DAT. The groundnut seeds treated with 0.5 ml of the oil had significantly higher (p<0.05) larval mortality (86.67%) than 0.3 and 0.4 ml with 26.67 and 48.67% larval mortality at 2 DAT respectively. However, significantly higher mortality was recorded at 0.4 ml when compared to 0.3 ml at 2 DAT. The results also showed that 0.5 ml/25 g seeds had a remarkable improvement in its insecticidal potential over 0.4 ml/25 g from 2 to 5 DAT. Groundnut seeds treated with 0.5 ml of the oil had significantly higher (p<0.05) adult mortality of 80.0% when compared with lower rates treatment having13.4 to 20.0% at 1 DAT. At 2 DAT, groundnut had significantly higher adult mortality of 86.6% when compared with lower rates of treatment having the same adult mortality of 26.6%. At 3 DAT, the seeds treated with 0.5 ml had significantly higher (p<0.05) larval mortality (93.3%) than lower rates of treatment with larval mortality which ranges from 6.67 to 46.7% while the control had no mortality. Groundnut seeds treated with 0.5 ml of the oil had significantly higher (p<0.05) adult mortality of 93.4% when compared with lower rates having adult mortality ranging from 33.4-66.0% while 6.6% adult mortality was recorded in the oil-free control at 3 DAT. Groundnut seeds treated with 0.3, 0.4 and 0.5 ml rates of guava leaf oil had significantly higher larval mortality of T. granarium (53.3, 60.0 and 93.3%) than 0.2 ml with 6.67% mortality at 4 DAT. Groundnut seeds treated with 0.4 and 0.5 ml of the oil maintained adult mortality of 66.0 and 93.4% respectively which were significantly higher (p<0.05) than mortality recorded in lowest rate of treatment (40.0%) and the control 4 DAT. At 5 DAT the seeds treated with 0.5 ml had 100.0% mean percentage larval mortality which was significantly higher (p<0.05) than lower rates of treatment. T International Journal of Recent Advances in Multidisciplinary Research 069 he results however, established that at 0.5 ml, higher larval mortality was recorded than lower rates, especially 0.4 ml/25 g rate of treatment which also had a substantial larval mortality recorded. At 5 DAT, groundnut seeds treated with 0.5 ml of the oil had significantly higher (p<0.05) adult mortality of 93.4% when compared with lower rates treatment at 5 DAT. There was also adult mortality of 53.4% at 0.2 and 0.3 ml which were not significantly different from the mortality recorded at 0.4 ml/25 g seeds. Comparison of larvae and adult mortality in seeds treated with P. guajava leaf oil When the mortality of larvae and adults of T. granarium due to P. guajava leaf oil were compared (Table 2), 80.0% adult mortality was obtained in 0.5 ml at 1 DAT. at 2 DAT, 86.6% adult mortality was obtained in 0.5 ml rate of treatment, showing that the oil extract had no contact toxicity on the insect, since 100% mortality of both larvae and adults was not recorded during the exposure period. Effect of P. guajava oil on larval emergence of T. granarium and seed weight loss Table 3 shows the mean percentage larval emergence of T. granarium in groundnut seeds treated with P. guajava leaf oil. The analysis of variance revealed that there was significant difference (p<0.05) in the mean percentage of T. granarium larvae that emerged from groundnut seeds treated with the oil at 30, 60 and 90 DAT. At 30 DAT, the seeds treated with 0.3 ml of P. guajava oil had more larval emergence (30.0%) when compared with those treated with 0.2 ml (45.0%), though the difference between the treatments was not significantly different (p>0.05). Similarly, the seeds treated with 0.3 ml of P. guajava oil had significantly lower mean percentage larval emergence when compared with those treated with higher rates
of treatment. Larvae emerged among the seeds treated with varying rates of treatment, but the seeds with the lowest rate of treatment and the control had the highest mean number of emerged larvae at 60 and 90 DAT. Results showed a difference of larval emergence in 0.4 ml which
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