Biorational management of the chiku moth Nephopteryx eugraphella (Ragonot)

Introduction

The sapota, scientifically known as Manilkara achras (Miller) Fosberg (synonym: Achras sapota L.), is a fruit-bearing tree belonging to the family Sapotaceae and subfamily Sapotoidae. Commonly referred to as chiku, ciku, dilly, naseberry, sapodilla, plum, and chico, this fruit has its origins in Mexico and Central America. Over time, it has been cultivated widely throughout the tropical regions of the world. The Spanish are credited with introducing sapota to the Philippines, from where it later spread to Malaysia and other regions (Purseglove, 1968) [7] . In India, sapota cultivation began in 1898 in Gholkwad, a village in Maharashtra, under the initiative of Patel Kavsaji Palanji (Chandha, 1993) [2] . selected and tagged. The percentage of infestation was recorded, and insecticidal treatments were applied using a gator sprayer when the pest population reached a high level. Pre-and post-treatment observations were recorded before and after 1 day before spray (1 DBS), 1 days after spray (3 DAS), 7 days after spray (7 DAS), and 10 days after spray (10 DAS). Obtained data were converted into percent reduction infestation by chiku moth over control through the following formula (Abbott, 1925) [1] .

Percent reduction over control =

Where, T = Percent infestation of chiku moth from the treated plot C = Percent infestation of chiku moth from the controlled plot

Results and Discussion

The efficacy of different bio-pesticides against chiku moth was observed separately on twig from the tree. The data regarding the effectiveness of various treatments at different intervals are described below in detail. The pre-treatment observations on chiku moth damage recorded one day before the first spray were found to be non-significant. The mean percentage of chiku moth damage recorded at different intervals after spray of various treatments was computed to pooled over time.

First spray

The observations recorded at 1 st day after first spray ( The observations recorded at 10 th day after first spray (Table 2) of bio-pesticides revealed that the NSKE 5% recorded the lowest damage (14.15%) which was statistically at par with treatment of B. bassiana 1.15 WP 0.0092%, N. rileyi 1.15 WP 0.0092% B. thuringiensis 5 WP 0.010% with 14.32, 17.79 and 18.53% damage, respectively. The next best treatments were B. bassiana 1.15 WP 0.007% (19.65%), M. anisopliae 1.15 WP 0.007% (20.03%) and Neemastra 1% (22.42%) damage, whereas, maximum damage due to chiku moth was recorded in the treatment of panchgavya 5% (23.43%). The pooled data presented in (Table 2), indicates that all the bio-pesticidal treatments had significantly reduced the chiku moth damage. Among them, NSKE 5% was the most effective treatment resulting 14.25% damage and it was at par with treatment of B. bassiana 1.15 WP 0.0092% (14.52%), N. rileyi 1.15 WP 0.0092% (17.39%) and B. t. 5 WP 0.010 (17.84%). B. bassiana 1.15 WP 0.007% (19.17%), M.anisopliae 1.15) WP 0.0092% (19.48%), M. anisopilae 1.15 WP 0.007% (22.25%) and neemastra 1% (22.67%) were the next best treatments for reduction chiku moth damage, whereas, the least control was observed in the treatment of panchgavya% (23.43%).

Second spray

The observations recorded at 1 st day after second spray (Table 3) of bio-pesticides revealed that NSKE 5% treatment recorded the lowest damage of chiku (12.23%) but it was statistically at par with treatment of B. t. 5 WP 0.01%, B. bassiana 1.15 WP 0.0092%, and N. rileyi 1.15 WP 0.0092% which resulted 12.26, 11.87 and 12.81% damage, respectively. The ext best treatments were B. bassiana 1.15 WP 0.007%, M. anisopliae 1.15 WP 0.0092%, M. anisopliae 1.15 WP 0.007% and neemastra 1% with ranging from 14.90 to 17.90% damage, whereas, maximum damage due to chiku moth was recorded in the treatment of panchgavya 5% 0.04% (17.90%). The observations recorded at 3 rd day after second spray (Table 3) of bio-pesticides revealed that the treatment of NSKE 5% found superior and it was recorded lowest percent damage by chiku moth (9.64%), but it was statistically at par with treatment B. bassiana 1.15 WP 0.0092%, B. thuringiensis 5 WP 0.01% and N. rileyi 1.15 WP 0.0092% and resulted 10.46, 10.95 and 11.52% damage, respectively. The next best treatments were B. bassiana 1.15 WP 0.007%, M. anisopliae 1.15 WP 0.0092%, M. anisopliae 1.15 WP 0.007% and neemastra 1% with ranging from 14.03 to 17.00% damage, whereas, maximum damage due to chiku moth was recorded in the treatment of panchgavya 5% 0.015% (17.63%).

The observations recorded at 7 th day after second spray (Table 3) of bio-pesticides revealed that the treatment of NSKE 5% recorded the lowest damage of chiku moth (7.95%) but it was statistically at par with treatment of B. bassiana 1.15 WP 0.0092%, N. rileyi 1.15 WP 0.0092% and B. thuringiensis 5 WP 0.01% resulted 8.31, 10.49 and 10.65% damage, respectively. It was followed by B. bassiana 1.15 WP 0.007% (13.68%), M. anisopliae 1.15 WP 0.0092% (13.96%), M. anisopliae 1.15 WP 0.007% (15.96%) and neemastra 1% (16.11%). whereas, maximum chiku moth damage was recorded in the treatment of pachgavya 5% 0.04% (16.40%).

The observations recorded at 10 th day after second spray (Table 3) bio-pesticides revealed that the treatment of NSKE 5% recorded the lowest damage of chiku moth (8.70%) but it was statistically at par with treatment of B. bassiana 1.15 WP 0.0092%, N. rileyi 1.15 WP 0.0092% and B. thuringiensis 5 WP 0.01% resulted 8.83, 11.34 and 11.72% damage, respectively. The next best treatments in order i.e., B. bassiana 1.15 WP 0.007% (13.94%), M. anisopliae 1.15 WP 0.0092% (14.88%), M. anisopliae 1.15 WP 0.007% (16.22%) and neemastra 1% (17.07%). whereas, maximum damage due to chiku moth was recorded in the treatment of pachgavya 5% 0.04% (17.59%). The pooled data presented in (Table 3), indicates that all the bio-pesticidal treatments reduced the chiku moth damage. Among them, NSKE 5% was the most effective treatment resulted 9.57% damage and it was at par with treatment of B. bassiana 1.15 WP 0.0092% (9.91%), B. t. 5 WP 0.010% (11.29%) and N. rileyi 1.15 WP 0.0092% (11.53%). Treatments B. bassiana 1.15 WP 0.007% (14.14%), M. anisopliae 1.15 WP 0.0092% (14.69%), M. anisopliae 1.15 WP 0.007% (15.49%) and neemastra 1% (17.07%) were found next best alternatives. Whereas, the least control was observed in the treatment of panchgavya 5% (17.38%).

Conclusion

Among different nine bio-pesticides tested in field conditions against chiku moth at the Jambuvadi Farm Junagadh Agricultural University Junagadh, application of NSKE 5% was found to be the most effective treatment and it was at par with B. bassiana 1.15 WP 0.0092%, It was followed by B. t. 5 WP 0.01% and N. rileyi 1.15 WP 0.009%. Whereas, treatments B. bassiana 1.15 WP 0.007%, M. anisopilae 1.15 WP 0.0092%, M. anisopilae 1.15 WP 0.007% and neemastra 1% were the next best treatments, whereas the highest percent damage was observed in the treatment of panchgavya 5%.

References

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