摘要:

The common mynaAcridotheres tristisLinn., the jungle crowCorvus macrorhynchusWagner and the house crowCorvus splendensViellot are the major pests of oil palm in India. Other birds like crow pheasantCentropus sinensisStresmann, parrotLoriculussp. and pariah kiteMilvus migransSykes also feedonoil 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.

ISSN:0143-6147    

DOI:10.1080/09670878909371379

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

We surveyed damage by the Eurasian wild boar (SusscrofaL.) to sugarcane, wheat, and maize in Faisalabad District and to groundnut in Rawalpindi, Attock, and Chakwal Districts in northern Punjab, Pakistan. In these areas, wild boars were the most important vertebrate pest in sugarcane, wheat, and maize, causing more damage than rats, porcupines, or rose‐ringed parakeets. They were lesser pests in groundnut. The estimated damage to sugarcane was 11.3%, wheat 3.0%, maize 6.7%, and groundnut 0.9%. Combined yield losses in sugarcane, wheat, and maize are estimated to be 130.9 million Pakistan Rupees (Rs.) (US $7.6 million)§1. The loss of groundnut equalled Rs. 6.4 million. Farmers spend up to 2 months guarding sugarcane and maize fields from wild boar attacks. Highly toxic poisons in baits are the only effective method of crop protection currently used in Pakistan. To minimize sugarcane damage, farmers are changing from growing soft‐rind, high sugar‐content varieties to hard‐rind, lower sugar‐content varieties. Recommendations are made for future research and development of methods to control the wild boar in Pakistan

ISSN:0143-6147    

DOI:10.1080/09670878909371380

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Ten replicated trials, in which 2.4% zinc phosphide, 0.005% brodifacoum and 0.005% bromadiolone were used to control rodents, were carried out in wheat fields. Single grid baiting with zinc phosphide followed by a baiting with brodifacoum or double baiting with brodifacoum or bromadiolone resulted in 89–93% rodent mortality. The pre‐flowering and flowering stages of wheat crop appeared to be more suitable for rodenticidal treatments than maturity stage; moist bait of bromadiolone produced considerable rodent mortality (64.67%) in maturing wheat. Rodents cut 8.08% tillers equivalent to a loss of 225.59 kg/ha wheat. Double rodenticidal treatments saved yield loss from 151.76 to 176.89 kg/ha resulting in cost benefit ratio of 1:19 to 1:28. In wheat fields where rodents were killed in previous rainy season crops the population of rodent burrow‐opening was very low varying from 14.42 to 18.92/ha. Burrow baiting trials in these wheat fields proved that rodenticidal treatments can be carried out profitably even at 2.22% level of damage

ISSN:0143-6147    

DOI:10.1080/09670878909371381

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Brodifacoum, a second generation single dose anticoagulant, was evaluated against the black rat,Rattus rattus wroughtoniHinton, a major rodent pest of cocoa in South India. Laboratory feeding trials using brodifacoum (0.005%) wax blocks showed cent per cent mortality in these rats by 1 day feeding. The active ingredient consumed varied from 0.35 mg to 9.17 mg/kg body weight (mean 3.71 ± 0.53 mg/kg). The mortality occurred from the third day to the tenth day of feeding with a maximum on the fifth day in females and on the sixth day in males. One, two and three baitings with brodifacoum baits at intervals of 10 days between baitings reduced the rat population by 76%, 95% and 97%, respectively in cocoa gardens. Moreover, cent per cent reduction in the damage was achieved by two baitings itself.

ISSN:0143-6147    

DOI:10.1080/09670878909371382

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Experience and knowledge gained by the activities of an ODA Plant Pathology Project are used to review aspects of plant protection in Northern Thailand, including important plant diseases, availability and development of extension services, pesticide use and the introduction of pests and diseases on exotic crops. Full records of fungal and bacterial diseases on 100 host plants are provided as an annotated list. Special attention is paid throughout to highland development programmes aimed at finding suitable subsistence and cash crops for the hill tribes to replace opium.

ISSN:0143-6147    

DOI:10.1080/09670878909371383

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

A study was undertaken to determine the influence of growing cowpea under three different cultivation practices on bacterial pustule development in the field. The disease spread within and between plants was shown to be least when cowpea were grown as a relay crop after maize during the long rains and when grown as an intercrop with maize during the short rains. During the short rains, disease incidence increased to 62.5% in cowpea maize intercrop, 75.0% in cowpea pure stand and 91.25% in cowpea‐maize relay crop after forty days from inoculation. During the long rains, disease incidence increased to 68.75% in cowpea‐maize relay crop, 100% in cowpea pure stand and 100% in cowpea‐maize intercrop after sixteen days inoculation. The different disease levels in the relay crops is attributed to the different weather that these crops received as they were planted at the end of the rainy season when maize had matured. Disease severity also had the same development as disease incidence.

ISSN:0143-6147    

DOI:10.1080/09670878909371384

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The losses in yield due to sorghum downy mildew of maize induced byPeronoscleospora sorghiwere assessed from 1982 to 1984 in the epidemic‐prone area of Nigeria. Plots of maize with different downy mildew incidences were obtained by planting seedlots containing different percentages of metalaxyl‐treated seeds. The losses in yield were directly proportional to the incidence of the disease. There was highly significant negative correlation between the incidence of downy mildew and grain yield.

ISSN:0143-6147    

DOI:10.1080/09670878909371385

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

A pea disease caused by a Brazilian strain of tomato spotted wilt virus (TSWV), as identified through host range, serology, and electron microscopy is described. TSWV was found in pods and seed testae, in addition to stems and leaves. Symptoms were usually more severe in cv. Triofin than in ‘Mikado’, both of which occupy more than 95% of the total area planted to dry peas in Brazil. Seed transmission was not detected. So far, the virus has been found to occur in five states in Brazil, although disease incidence has generally been low.

ISSN:0143-6147    

DOI:10.1080/09670878909371386

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Field experiments were conducted at Jobner (Rajasthan) during the winter seasons of 1982 and 1983 to evaluate certain physical and chemical weed control systems in fenugreek at two levels of applied phosphorus. The experiments comprised four herbicides (fluchloralin, pendimethalin, thiobencarb, and chloramben) at two levels each, manual weeding at three levels; and an unweeded check. The second factor, namely, application of phosphorus was evaluated at 0 and 40 kg P2O5/ha. The soil of the experiment site was loamy sand, containing 0.16% organic carbon. The results showed that amongst the herbicides, preemergent pendimethalin at 0.75 kg/ha controlled the weeds most effectively and gave 8.91 q/ha fenugreek seed yield, which was more than twice the seed yield obtained from the unweeded check plots. The twice hoed plots were found to give 1.32 q/ha higher seed yield than the pendimethalin herbicide treatment, but the benefit‐cost ratio was found higher for the herbicidal treatment. Application of phosphorus at 40 kg P2O5/ha was found to bring about significant increase in the seed yield of fenugreek by 59 kg/ha over control, without any interaction with the weed control treatments.

ISSN:0143-6147    

DOI:10.1080/09670878909371387

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Field experiments were conducted to determine the effectiveness of herbicides in controllingRottboellia cochinchinensis(Lour.) W. D. Clayton andCyperus rotundusL. in upland rice(Oryza sativaL.) at different moisture regimes as imposed by a line source sprinkler system. Preemergence application of pendimethalin [N‐(1‐ethylpropyl)‐3,4‐dimethyl‐2,6‐dinitrobenzenamine] was highly effective in controllingR. cochinchinensisirrespective of soil moisture after herbicide application. Bentazon [3‐(1‐methylethyl)‐(1H)‐2,1,3‐benzothiadiazin‐4(3H)‐one 2,2‐dioxide] and 2,4‐D [(2,4‐dichlorophenoxy)acetic acid] applied at postemergence effectively controlledC. rotunduswhen moisture supply was well above pan evaporation. These herbicides also had no adverse effect on rice stand and resulted in higher yield over thecontrol.Water application rates above upland pan evaporation for a season‐long period was essential to obtain a high response to weed control either by herbicidesorhand weeding. The data suggest that proper weed control by herbicides or hand weeding will not result in high upland rice grain yields if moisture level from rains fall below the critical level.

ISSN:0143-6147    

DOI:10.1080/09670878909371388

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor