|Keywords (Extracted from title, table of contents and abstract of thesis)
pulse beetle, callosobruchus chinensis l., coleoptera: bruchidae, chickpea, pest, black pepper (piper nigrum), red chilies (capsicum annum), cloves (syzygium aromaticum), neem (azadirachta indica), datura (datura stramonium), garlic (allium sativum), turmeric (curcuma longa), meliaceae, solanaceae, myrtaceae, piperaceae, euphorbiaceae,cruciferae, fly ash, turpentine oil, m minimum buckley, d. labiatus shuckard, camponotus rufipes fabricius
Chickpea ranks 3rd among pulses on global basis and constitutes 88% of the rain-fed cropping system. A survey was conducted to observe the pest status of Pulse Beetle (PB), Callosobruchus chinensis L., in the Punjab province of Pakistan. Percent damage/infestation by PB to stored chickpea proved this pest as a major one, causing more than 10% damage. In the present studies, plant powders and extracts of black pepper (Piper nigrum), red chilies (Capsicum annum), cloves (Syzygium aromaticum), neem (Azadirachta indica), datura (Datura stramonium), garlic (Allium sativum) and turmeric (Curcuma longa) were found effective against PB but black pepper powder and neem extract were the most effective. Plant extracts, however, were comparatively better than powders in their effectiveness. Among plant oils, castor (Ricinu communis), neem (Azadirachta indica), taramera (Eruca sativa), cloves (Syzygium aromaticum), datura (Datura stramonium), garlic (Allium sativum) and turmeric (Curcuma longa) showed significant insecticidal properties in controlling PB. Plant oils provided better results when compared with their dissolution in ether and acetone, however, ether proved to be better solvent than acetone. In synergistic studies, some combinations having higher ratios of castor and neem oils presented good results even at their lower application rates. In studies pertaining to contact/fumigant toxicity of plant oils applied on filter paper discs against PB, potent insecticidal activity was produced by oils of castor, neem and taramera while oils of datura and clove also provided effective control. The results of the studies revealed that plants belonging to families Meliaceae, Solanaceae, Myrtaceae, Piperaceae, Euphorbiaceae and Cruciferae showed promising insecticidal properties against PB. Among miscellaneous materials as post harvest grain protectants, fly ash proved to be the best in managing PB infestation to lower levels. Turpentine oil also provided effective control followed by cow-dung ash while red soil powder and kikar ash were less effective at their lower application rates and were similar to the control in effectiveness. Plant materials applied both to cloth bag and chickpea grains inside, provided efficient protection to grains in terms of insect number, damaged grains and percent foreign matter, which increased gradually and significantly in un-treated bags after every month. The correlation of temperature for these months with the insect number, damaged grains and foreign matter was significantly positive while it was positive but non-significant with relative humidity. There was negative but non-significant correlation between temperature and relative humidity. The grains from treated and un-treated bags were subjected to germination test after 6 months storage and it was observed that bags with higher PB infestation exhibited lower germination percentage and vice versa. However, all the plant material treated samples provided significantly higher germination than the control. The sensory analysis of grain samples from bags was also carried out to assess the intensity of off-flavour in treated and untreated samples. Besides untreated bags, coopex dust treated bags also provided significantly higher intensity of off-flavour. In experiments regarding management of PB using high and low temperatures, all the temperature treatments (15 °C, 20 °C, 25 °C, 35 °C, 40 °C and 45 °C) were significantly better in their exposure of 10 minutes as compared to that of 5 minutes, indicating that longer exposures to temperatures beyond temperature preferendum gave better results in reducing PB infestation. However, these temperatures in almost every exposure showed marked and significantly better effect in managing PB when compared with 30 °C. Temperature treatment of 15 °C with 10 minutes exposure proved to be the best showing the minimum days to mortality, eggs per grain, holes per grain, fresh adults emerged, weight loss and the maximum inhibition of PB. In Antixenosis and antibiosis tests for cultivar resistance of chickpea against PB, varieties with hard, rough, wrinkled and thick seed coat proved to be more resistant when compared with varieties having smooth, soft and thin seed coat. The ant species, namely, M minimum Buckley, D. labiatus Shuckard and Camponotus rufipes Fabricius, especially collected from forest habitats, were efficient predators against different developmental stages of PB. However, C. rufipes proved effective for adult predation and M minimum for egg predation while D. labiatus was effective for larval and pupal predation.