Investigations on avian pests of oil palm,Elaeis guineensis Jacq. in India†     

K. Dhileepan 《国际虫害防治杂志》2013,59(3):273-277

Abstract

The common myna Acridotheres tristis Linn., the jungle crow Corvus macrorhynchus Wagner and the house crow Corvus splendens Viellot are the major pests of oil palm in India. Other birds like crow pheasant Centropus sinensis Stresmann, parrot Loriculus sp. and pariah kite Milvus migrans Sykes also feed on oil palm fruits. These birds feed on the fleshy mesocarp of the ripe fruits resulting in heavy fruit loss, significantly reducing oil yield. Gizzard and intestinal content analysis indicated that oil palm fruits are the major source of food for these birds. Observations on 1657 oil palm fruit bunches during 1985–86 revealed that 76% of the ripe bunches and 5.6% of the unripe bunches were damaged by birds. The damage by birds was either ‘partial’ or ‘complete’, where 40–50% and 80–100% respectively, of the individual fruit weight was lost. The partial fruit damage was more common in 130–160 day‐old bunches and the complete fruit damage increased after 150 days of fruit set. Fruit loss due to bird damage was higher in palms in the border area of the plantation (2.3 kg/bunch) than in the interior (1.3 kg/bunch). It is estimated that around 2.8 tonnes of fresh fruits/ha/yr, equivalent to 420 kg of palm oil, are lost due to bird damage.  相似文献   

Weed–pathogen interactions and elevated CO2: growth changes in favour of the biological control agent     

A Shabbir  K Dhileepan  N Khan  S W Adkins 《Weed Research》2014,54(3):217-222

In this study, we used Parthenium hysterophorus and one of its biological control agents, the winter rust (Puccinia abrupta var. partheniicola) as a model system to investigate how the weed may respond to infection under a climate change scenario involving an elevated atmospheric CO₂ (550 μmol mol^?1) concentration. Under such a scenario, P. hysterophorus plants grew significantly taller (52%) and produced more biomass (55%) than under the ambient atmospheric CO₂ concentration (380 μmol mol^?1). Following winter rust infection, biomass production was reduced by 17% under the ambient and by 30% under the elevated atmospheric CO₂ concentration. The production of branches and leaf area was significantly increased by 62% and 120%, under the elevated as compared with ambient CO₂ concentration, but unaffected by rust infection under either condition. The photosynthesis and water use efficiency (WUE) of P. hysterophorus plants were increased by 94% and 400%, under the elevated as compared with the ambient atmospheric CO₂ concentration. However, in the rust‐infected plants, the photosynthesis and WUE decreased by 18% and 28%, respectively, under the elevated CO₂ and were unaffected by the ambient atmospheric CO₂ concentration. The results suggest that although P. hysterophorus will benefit from a future climate involving an elevation of the atmospheric CO₂ concentration, it is also likely that the winter rust will perform more effectively as a biological control agent under these same conditions.  相似文献   

Integrated use of biological approaches provides effective control of parthenium weed     

Asad Shabbir  Kunjithapatham Dhileepan  Myron Zalucki  Naeem Khan  Steve Adkins 《Archives of Agronomy and Soil Science》2018,64(13):1861-1878

Parthenium weed (Parthenium hysterophorus L.; Asteraceae) is an invasive weed species in agro-ecosystems. It causes huge losses to native biodiversity and agricultural productivity. This study was conducted to assess the combined effect of a leaf-feeding beetle, (Zygogramma bicolorata Pallister; Chrysomelidae) and suppressive plant species, bull Mitchell grass (Astrebella squrossa C.E. Hubb.; Poaceae) or butterfly pea (Clitoria ternatea L.; Fabaceae) on parthenium weed under shade house conditions. The suppressive plant species significantly reduced the parthenium weed height (16%), biomass (29%) and seed production (42%), in the absence of Z. bicolorata. However, this suppressive ability was further enhanced in the presence of Z. bicolorata. The combined effect of the suppressive plant species and Z. bicolorata further reduced the parthenium weed height (46%), biomass (66%) and seed production (95%). The combination also had a significant negative effect upon seed fill, decreasing the reproductive output of the current generation. The presence of Z. bicolorata also had positive effect on the biomass (10%) and plant height (11%) of both suppressive species. So, the combined use of suppressive plant species and the biological control agent suppressed parthenium weed more effectively than their sole use. Such integrated approaches should be prioritized for future management of parthenium weed.  相似文献