FIELD EVALUATION OF BIO-EFFICACY OF NEEM EXTRACTS AGAINST Hymenia recurvalis F. (LEPIDOPTERA: NYMPHALIDAE) ON AMARANTHUS IN IBADAN, NIGERIA

Author(s): Aderolu I. A. and Omoloye A. A.
Volume/Issue: Volume 3 , Issue 1 (2023)

ABSTRACT:

Field evaluations were conducted at the University of Ibadan, Southwest Nigeria, to assess the efficacy of neem (Azadirachta indica A. Juss) extracts and Karate (ʎ-cyhalothrin) in the management of Beet worm Moth, Hymenia recurvalis Fabricius (Lepidoptera: Nymphalidae) on Amaranthus. The neem treatments contain Neem Leaf Extract (NLEE) (at 1200ml ha-1), Neem Root Ash Extract (NRAE) (at 1200ml ha-1), and Amended Neem Extract (AMNE) in ratio1:1 (600ml neem root ash extract + 600ml neem leaf extract) were compared with ʎ-cyhalothrin 720EC and no therapy. The treatments were replicated four times and structured in a Randomized Complete Block Design (RCBD). Data acquired were subjected to Analysis of Variance (ANOVA) and significant means were separated using Student Newman Keuls (SNK) at a 5% probability threshold. The data revealed that the incidence and abundance of H. recurvalis were drastically affected by the neem extract treatments. Leaf yield was substantially (p < 0.05) larger in all the neem-treated plots than in the control. The 21.9 percent weight yield of Amaranthus in plots treated with AMNE was substantially (p < 0.05) more effective than Karate720EC with a 20.5 percent leaf yield of the Amaranthus. However, none of the sole NRAE and lone NLEE was as much (p<0.05) effective as the synthetic pesticide (Karate) in Amaranthus yield. In addition, the reduction in the number of defoliated leaves treated with AMNE and karate720EC treatments was not significantly (p < 0.05) different. With respect to Amaranthus yield characteristics, AMNE dramatically (p < 0.05) enhanced the Amaranthus leaf area, plant height, and stem diameter by thirteen percent, three percent, and six percent correspondingly compared to the NLEE alone and NRAE sole. Among others, AMNE had notably (p < 0.05) the highest values of Amaranthus growth parameters followed by karate > NLEE > NRAE respectively. The AMNE substantially (P < 0.05) diminished the H. recurvalis population and amount of defoliated leaves by forty-two percent and seventy percent respectively. In comparison with the AMNE, ʎcyhalothrin cut the number of defoliated leaves per sample plot by fifty-eight percent. However, there was no significant (P < 0.05) difference between karate and AMNE in the population of H. recurvalis on Amaranthus. For yield characteristics, AMNE greatly (P < 0.05) enhance the Amaranthus yield rises by seventeen percent, sixteen percent, and seven percent for leaf area, plant height, and stem diameter correspondingly compared to ʎ-cyhalothrin. However, the influence of NRAE and NLEE are not statistically (p < 0.05) different on Amaranthus yield. Therefore, the AMNE applied at 1200L/ha (3L/25m2) was ideal for the effective management of H. recurvalis on Amaranthus. Therefore, the AMNE applied at 1200L/ha (3L/25m2) was best for effective H. recurvalis on Amaranthus.

KEYWORDS:

 Neem Leaf Extract (NLEE), Neem Root Ash Extract (NRAE), Amended Neem Extract (AMNE), Karate 720EC, Hymenia recurvalis, Amaranthus spp.