Monoculture and intensive fertiliser use in the cultivation of Robusta coffee(Coffea canephora var.Robusta)and black pepper(Piper nigrum L.)have led to soil degradation and increased disease pressure in Vietnam's ...Monoculture and intensive fertiliser use in the cultivation of Robusta coffee(Coffea canephora var.Robusta)and black pepper(Piper nigrum L.)have led to soil degradation and increased disease pressure in Vietnam's Central Highlands.To identify key factors driving soilborne diseases and threatening sustainable production,a soil and root survey was conducted across three provinces:Gia Lai,Dak Lak,and Dak Nong.Soils were characterised by high clay content(51.2-62.0%),moderate silt(35.5-46.0%),and low sand(2.5-2.8%),with a notably low cation exchange capacity(7.72-8.04 cmol_(c) kg^(−1)).The soils were strongly acidic,with average pH values of 4.51 in coffee farms and 5.45 in pepper farms.Despite sufficient levels of nitrogen(N),phosphorus(P),and potassium(K),soilborne pathogens were widespread.Fusarium spp.were detected in all samples,Phytophthora spp.in 64-76%of black pepper farms,and plant-parasitic nematodes in 67-84%of farms,with Meloidogyne spp.predominant.Fusarium density increased with soil acidity in coffee plantations.In coffee,nematode density was positively correlated with N input,while in black pepper,N was negatively correlated with Phytophthora.Organic matter and available K were negatively associated with Fusarium in coffee but positively with Phytophthora in black pepper.These findings underscore the need for integrated management of nutrients and pathogens to sustain perennial crop production in the region.展开更多
Mass-rearing of Orius similis Zheng on two preys,Aphis craccivora Koch and eggs of Corcyra cephalonica Stainton at three constant temperatures(22,26 and 30°C)and 60%±10%RH and 16:8 L/D photoperiod under labo...Mass-rearing of Orius similis Zheng on two preys,Aphis craccivora Koch and eggs of Corcyra cephalonica Stainton at three constant temperatures(22,26 and 30°C)and 60%±10%RH and 16:8 L/D photoperiod under laboratory conditions was investigated to study the effect of different temperatures and different preys on the biology of O.similis.The highest survival rate(%)of nymphal stages was 81.14%and the longest oviposition period for females(20.6 d)was recorded at 26°C.Also,the highest fecundity of female also recorded at 26°C.The highest rate of nymphal feeding consumption was(122.5 individuals of A.cracivora)also,recorded at 26°C.As well as,the two preys had significant effects on the biological characteristics of O.similis.The highest survival rate for nymphal stage was recorded when O.similis nymphs fed on A.cracivora.Therefore,the longest survival rate was founded in the nymphs which fed on the individuals of A.cracivora.During the nymphal period of O.similis which consumed more individuals of A.cracivora than the eggs of C.cephalonica.These results on the effect of three constant temperatures and two preys on the biology of O.similis will share to improve the rearing of O.similis in biological control agents in China and share to suppress the population of pests in field and greenhouse.展开更多
基金funded by the Australian Centre for International Agricultural Research(ACIAR)project“AGB-2018-175:Enhancing smallholder livelihoods in the Central Highlands of Viet Nam through improving the sustainability of coffee and black pepper farming systems and value chains”and Deakin University.
文摘Monoculture and intensive fertiliser use in the cultivation of Robusta coffee(Coffea canephora var.Robusta)and black pepper(Piper nigrum L.)have led to soil degradation and increased disease pressure in Vietnam's Central Highlands.To identify key factors driving soilborne diseases and threatening sustainable production,a soil and root survey was conducted across three provinces:Gia Lai,Dak Lak,and Dak Nong.Soils were characterised by high clay content(51.2-62.0%),moderate silt(35.5-46.0%),and low sand(2.5-2.8%),with a notably low cation exchange capacity(7.72-8.04 cmol_(c) kg^(−1)).The soils were strongly acidic,with average pH values of 4.51 in coffee farms and 5.45 in pepper farms.Despite sufficient levels of nitrogen(N),phosphorus(P),and potassium(K),soilborne pathogens were widespread.Fusarium spp.were detected in all samples,Phytophthora spp.in 64-76%of black pepper farms,and plant-parasitic nematodes in 67-84%of farms,with Meloidogyne spp.predominant.Fusarium density increased with soil acidity in coffee plantations.In coffee,nematode density was positively correlated with N input,while in black pepper,N was negatively correlated with Phytophthora.Organic matter and available K were negatively associated with Fusarium in coffee but positively with Phytophthora in black pepper.These findings underscore the need for integrated management of nutrients and pathogens to sustain perennial crop production in the region.
文摘Mass-rearing of Orius similis Zheng on two preys,Aphis craccivora Koch and eggs of Corcyra cephalonica Stainton at three constant temperatures(22,26 and 30°C)and 60%±10%RH and 16:8 L/D photoperiod under laboratory conditions was investigated to study the effect of different temperatures and different preys on the biology of O.similis.The highest survival rate(%)of nymphal stages was 81.14%and the longest oviposition period for females(20.6 d)was recorded at 26°C.Also,the highest fecundity of female also recorded at 26°C.The highest rate of nymphal feeding consumption was(122.5 individuals of A.cracivora)also,recorded at 26°C.As well as,the two preys had significant effects on the biological characteristics of O.similis.The highest survival rate for nymphal stage was recorded when O.similis nymphs fed on A.cracivora.Therefore,the longest survival rate was founded in the nymphs which fed on the individuals of A.cracivora.During the nymphal period of O.similis which consumed more individuals of A.cracivora than the eggs of C.cephalonica.These results on the effect of three constant temperatures and two preys on the biology of O.similis will share to improve the rearing of O.similis in biological control agents in China and share to suppress the population of pests in field and greenhouse.
