ABSTRACT
Silkworm larvae when fed on leaves from mulberry (Morus laevigata) tree given soil treatment with 2 kg well rotten F Y M along with 0.2%N concentration consumed more food, gained significantly more weight and produced heavier cocoons, as compared to those fed on leaves from trees treated with 2kg FYM + 0.1%N, 2kg FYM + 0.3%N, 2kg FYM + 0.4 %N and 2kg FYM alone.
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DOI: 10.3923/ajps.2002.93.94
URL: https://scialert.net/abstract/?doi=ajps.2002.93.94
INTRODUCTION
Silkworm (Bombyx mori L.) is a monophagous insect feeding on mulberry leaves only. Silkworm is one of the most beneficial domesticated insects. The development and growth of an insect is dependent as essential food elements. Therefore, the Scientists have experimented with supplementation of various nutrients on the mulberry leaves for feeding the Silkworm and promoting both silk quality and quantity. Ashfaq et al. (1998) found that silkworm larvae when fed on mulberry leaves treated with 0.2N + 0.05%Cu concentrations solution consumed more food, gained more larval weight and produced heavier cocoons as compared to untreated or other treated leaves. Ashfaq et al. (1998a) 0.2N + 0.1P + 0.05%Cu solution and (Ashfaq et al., 1998b) 0.2N + 0.1P + 0.3K + 0.05%Cu solution, whose concluded that when larvae fed on these treated leaves consumed more food, gained more larval weight and produced heavier cocoons as compared to larvae fed on untreated or other treated leaves. Rasool (1995) concluded that larvae fed on leaves treated with 0.2N + 0.5%Mn concentrations solution, consumed more food, gained significantly more weight and produced heavier cocoons as compared to those fed on other treated or untreated leaves. Zaman (1995) resulted that silkworm larvae when fed on leaves treated with 0.15Mg + 0.2%N concentrations solution consumed more food, gained more larval weight and produced heavier cocoons as compared with those fed on untreated leaves.
The present studies were aimed for observing the feeding effect of 2kg F Y M along with different N concentrations prepared from Urea 46% and 2 kg F Y M alone applied to mulberry trees, through soil application at ten days interval with irrigation, on cocoon weight.
MATERIALS AND METHODS
The Eggs of Korean strain, F1 Hybrid (JAM 108 X JAM 107) of Silkworm, Bombyx mori L. were procured from Punjab Forest Department, Lahore. Eggs were placed for hatching during the last week of February in the growth chamber at 28 ± 2 °C and 70-80 % relative humidity. Soon after hatching, silkworm larvae were divided into six groups including check, following Randomized Complete Block Design (RCBD) with three replications and each replication had thirty larvae. Two kg well rotten Farm Yard Manure (F Y M) along with Urea 46% in different N concentrations, 0.1, 0.2, 0.3, 0.4% and two kg well rotten F Y M alone were applied at ten days interval through irrigation to five sprouted mulberry trees of two years age growing in the Entomological Experimental Area, University of Agriculture, Faisalabad. The treatments were as follows,
T1 | 2 kg well rotten F Y M + 0.1% N |
T2 | 2 kg well rotten F Y M + 0.2% N |
T3 | 2 kg well rotten F Y M + 0.3% N |
T4 | 2 kg well rotten F Y M + 0.4% N |
T5 | 2 kg well rotten F Y M alone |
T6 | Check |
The first and second instar larvae were fed on chopped green leaves while the remaining three instars were fed on whole green leaves plucked from trees which received different treatments. Food was supplied to larvae twice a day first at 8.00 am and then at 8.00 pm and was continued till the larvae were fulfed and ready for pupation. Thirty larvae of each group were separately reared in 10X10 cm2 sized Eighteen cardboard trays upto third instar while fourth and fifth instar larvae were reared in 10X20 cm2 cardboard trays (Ashfaq et al.,1998a; Ashfaq et al.,1998b; Akram et al.,1993; Nabila et al., 1993; Shafiq and Haq, 1993; Mahmood et al., 1989). The larval weight was recorded on the last day of each instar using electronic balance. The residual leaves and feces were collected separately and dried in the oven at 100oC for 24 hours. The food consumption was measured by subtracting the dry weight of residual leaves directly from the determined total dry weight of leaves offered to silkworm. Cocoon weight with and without pupae under different treatments was also recorded. The data were analyzed sadistically and Duncans multiple range (DMR) test was applied to test the significance of results (Steel and Torrie, 1981).
Results and Discussion
Food Consumption: The first instar Bombyx mori larvae maximum consumed average food 14.49 mg larva-1 when fed on mulberry leaves obtained from tree treated with 2kg F Y M + 0.2%N. Similarly, larvae consumed average food 14.01, 13.86, 13.69, 13.53 and 13.41 mg larva-1 when fed on leaves from trees received 2kg F Y M + 0.1%N, 2 kg F Y M + 0.3%N, 2kg F Y M + 0.4%N, 2kg F Y M alone and untreated, respectively. The maximum average quantity of food consumed in the second, third, fourth and fifth instars was 27.83, 85.08, 725.93 and 4408.69 mg larva-1 when Bombyx mori larvae fed on mulberry leaves obtained from tree treated with 2kg F Y M + 0.2%N (T2), respectively as against larvae consumed minimum average food 14.39, 68.98, 445.61 and 2808.23 mg larva-1 when fed on leaves from tree received no treatment (T6). The average food consumption trend in all other treatments in all rest of instars were similar to first instar (Table 1). However, T2 was considered the best treatment among the remaining treatments. Thus the research findings are in agreement with the work of Ashfaq et al. (1998) who found that silkworm larvae when fed on mulberry leaves treated with 0.2N + 0.05%Cu solution consumed more food as compared to untreated leaves. Similar studies were also carried out by Ashfaq et al. (1998a) 0.2N + 0.1P + 0.05%Cu solution, (Zaman, 1995) 0.15Mg + 0.2%N solution, (Tariq, 1993) 0.2N + 0.05P + 0.1K + 0.1% Ca solution, (Rasool, 1995) 0.2N + 0.5%Mn solution, (Ishtaiq and Akhtar, 1992) 0.2N + 0.1Ca + 0.1%K solution, (Ashfaq et al., 1998b) 0.2N + 0.1P + 0.3K + 0.05%Cu solution, (Akram et al., 1993) 0.3%Ca solution and Nabila et al. (1993) 0.3%N solution, whose concluded that when larvae fed on these treated leaves consumed more food as compared to larvae fed on untreated or other treatments. Similarly, Shafiq and Haq (1993), Liaw and Shikata (1980) whose reported that feeding silkworm larvae on top, young and tender leaves, are usually rich in "N" consumed better food than when fed on coarse and old leaves which are low in "N". Mahmood et al. (1989) found that Bombyx mori larvae fed on 0.2%N concentration, consumed more food, as compared to those larvae fed on leaves treated with 0.1N, 0.3N, 0.4%N concentrations both in wet and dry conditions.
Larval weight: First instar Bombyx mori larvae maximum gained in average weight 4.11 mg larva-1 when fed on mulberry leaves fetched from tree treated with 2kg F Y M + 0.2%N. Similarly, larvae gained in average weight 3.99, 3.86, 3.79, 3.63 and 3.35 mg larva-1 when fed on leaves from trees received 2kg F Y M + 0.1%N, 2kg F Y M + 0.3% N, 2kg F Y M + 0.4%N, 2kg F Y M alone and untreated, respectively. The maximum gained in average weight in the second, third, fourth and fifth instars was 13.76, 63.56, 348.92 and 1179.17 mg larva-1 when Bombyx mori larvae fed on mulberry leaves fetched from tree treated with 2kg F Y M + 0.2% N (T2), respectively as against minimum larvae gained in average weight 12.03, 45.20, 254.72 and 718.22 mg larva-1 when fed on leaves fetched from untreated tree (T6). The gained in average weight trend in all other treatments in all rest of four instars were similar to first instar (Table 2).
Table 1: | Effect of FYM + differentNconcentrations on average food consumption of silkworm |
Values followed by same letters do not differ significantly at 5% level of probability |
Table 2: | Effect of F Y M + different N concentrations on average gained in silkworm, weight |
Values followed by same letters do not differ significantly at 5% level of probability. |
Table 3: | Effect of F Y M + different N concentrations on average cocoon weight of silkworm |
Values followed by same letters do not differ significantly at 5% level of probability. |
However, T2 was considered the best treatment among the remaining treatments. The present findings tally with Ashfaq et al. (1998) found that silkworm larvae when fed on mulberry leaves treated with 0.2N + 0.05%Cu solution gained significantly more weight as compared to untreated leaves. Similarly, Ashfaq et al. (1998a), 0.2N + 0.1P + 0.05%Cu solution, (Zaman, 1995) 0.15Mg + 0.2N solution, (Tariq, 1993) 0.2N + 0.05P + 0.1K + 0.1%Ca solution, (Rasool, 1995) 0.2N + 0.5%Mn solution, (Ishtaiq and Akhtar, 1992) 0.2N + 0.1Ca + 0.1%K solution, Ashfaq et al. (1998b) 0.2N + 0.1P + 0.3K + 0.05%Cu solution, (Akram et al., 1993) 0.3%Ca solution and Nabila et al. (1993) 0.3%N solution, whose concluded that when larvae fed on these treated leaves gained significantly more weight as compared to fed on leaves received from untreated or other treatments. Similar studied were also carried out by Shafiq and Haq (1993), Liaw and Shikata (1980) reported that feeding silkworm larvae on top, young and tender leaves, are usually rich in "N" resulted in better larval development than when fed on old and coarse leaves which are low in "N". Javaid (1991) concluded that mulberry leaves treated with 0.3K+ 0.2%N gave best result for the larval development. The results are in agreement with Mahmood et al. (1989) found that 0.2%N concentration, Bombyx mori larvae gained significantly more weight as compared to the larvae fed on leaves treated with 0.1N, 0.3N, 0.4%N concentrations both in wet and dry conditions.
Cocoon weight: The average maximum cocoon weight with pupa was 400.48 mg larva-1 and without pupa was 222.41 mg larva-1 when it fed on 2kg F Y M + 0.2%N treated leaves as against 394.10, 390.64, 383.47, 379.53 and 267.36 mg larva-1 with pupa; 211.73, 207.75, 204.88, 198.99 and 137.75 mg larva-1 without pupa in case of 2kg F Y M + 0.1%N, 2kg F Y M + 0.3%N, 2kg F Y M + 0.4%N, 2kg F Y M alone and untreated, respectively. Thus the effect of 2kg F Y M + 0.2%N treatment (T2) differed from all other treatments including check (Table 3). Present findings are in the line of Ashfaq et al. (1998) who found that silkworm larvae when fed on mulberry leaves treated with 0.2N + 0.05%Cu solution produced heavier cocoons as compared to untreated leaves. Similar, studied were also carried out by Ashfaq et al. (1998a), 0.2N + 0.1P + 0.05%Cu solution, (Zaman, 1995) 0.15Mg + 0.2%N solution, (Tariq, 1993) 0.2N + 0.05P + 0.1K + 0.1%Ca solution, (Rasool, 1995) 0.2N + 0.5%Mn solution, (Ishtaiq and Akhtar 1992) 0.2N + 0.1Ca + 0.1%K solution, Ashfaq et al. (1998b) 0.2N + 0.1P + 0.3K + 0.05%Cu solution, (Akram et al. (1993) 0.3%Ca solution and Nabila et al. (1993) 0.3%N solution, whose concluded that larvae when fed on these treated leaves produced heavier cocoon weight as compared to larvae fed on leaves of untreated or other treatments leaves. Similarly, Shafiq and Haq (1993), Liaw and Shikata (1980), Askari and Sharan (1982) and Tulog and Catli (1983) whose reported that feeding silkworm larvae on top, young and tender leaves, are usually rich in "N" resulted in more cocoon weight than when fed on old and coarse leaves which are low in "N". Javaid (1991) concluded that mulberry leaves treated with 0.3K + 0.2%N gave best result for cocoon weight larva-1. Mahmood et al. (1989) found that 0.2%N concentration produced heavier cocoons as compared to the larvae fed on leaves treated with 0.1N, 0.3N, 0.4%N concentrations both in wet and dry conditions. Haq and Saleem (1985) found that feeding of mulberry leaves treated with 0.2%N concentration significantly increased the cocoon weight as compared with those fed on untreated leaves and treated with 0.1N and 0.4%N concentrations. Krishnaswami et al. (1971) reported that soil application of N significantly improved cocoon weight.
The silkworm larvae gave responded to mulberry leaves of the treated trees. However, 2kg F Y M + 0.2%N (T2) was the best treatment due to which the highest larval and cocoon weight was recorded.
REFERENCES
- Ashfaq, M., Z. Qaisar and M. Saleem, 1998. Effect of Impregnated mulberry Leaves with the optimum dosages of N, Ca, P and Cu on the larval development and silk yield of silkworm, Bombyx mori L. Pak. Entomol., 20: 17-20.
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