摘要:

Between 1982 and 1985, Nigerian cassava fields were periodically sampled through three crop growing seasons to analyze the within and between‐plant distribution of CM as affected by weather (dry and rainy season) using the mean crowding statistics and Taylor's power law. Enumerative and binomial sampling plans were developed which take into consideration the seasonal changes in the spatial distribution patterns of CM. The costs of the two procedures were compared to select the most cost‐efficient sampling plan.

ISSN:0143-6147    

DOI:10.1080/09670878909371356

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Sex pheromone‐baited traps were used to monitor populations ofPrays oleae(Bern) in an olive grove near Granada, Spain, eyery year from 1979 to 1987 during the flight of adults that gives rise to the larvae of the fruit generation. Attempts at establishing a correlation between the catches of adult P.oleaein sex pheromone baited traps and subsequent fruit infestations were successful in each year separately, but not when the data for all yearswerecombined. However, when account was taken of the degree of synchrony between adult emergence and the stage of development of the fruit, from the point of view of suitability for oviposition as perceived by the females, good correlations could be obtained. A very high coefficient was therefore obtained when fruit infestation was correlated with accumulated adult catches from the date of commencement of oviposition. The practical applications of the findings are discussed.

ISSN:0143-6147    

DOI:10.1080/09670878909371357

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The yield losses caused by the Asian rice gall midgeOrseolia oryzaeWood‐Mason in 15 traditional or high yielding varieties, studied by the paired plot (unprotected and protected) technique, ranged from‐0.06 in CR.1014 to 1.1% in CR.58‐MR.1538 for every unit per cent increase in silver shoots. Based on this, CR.1014 was identified as highly tolerant with no yield loss (‐0.06%) followed byJagannathwith 0.27%, while the other entries were rated as either moderately tolerant (0.3–0.60%) or least tolerant (0.61 % and above).

ISSN:0143-6147    

DOI:10.1080/09670878909371358

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

ISSN:0143-6147    

DOI:10.1080/09670878909371359

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Two sampling techniques used in East Africa onAntestiopsisspecies in Arabica coffee were evaluated for effectiveness. Visual inspection as a sampling technique gave lower means per tree than test‐spraying, implying that the latter may be more accurate. The advantages of both methods are discussed.

ISSN:0143-6147    

DOI:10.1080/09670878909371360

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

ISSN:0143-6147    

DOI:10.1080/09670878909371361

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Rice plant,Oriza sativa Lwas found to produce a volatile attractant forLeptocorisa acuta(Thumb), one of the most important pests of rice. Laboratory bioassay using an olfactometer showed that both sexes ofLeptocorisaare attracted to steam distillates of rice grain in its milk stage. Steam distillates of blooming stage and the matured grains did not attract the pest. Field trails carried out with active samples as baits, attracted both sexes ofLeptocorisaquite successfully.

ISSN:0143-6147    

DOI:10.1080/09670878909371362

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

ISSN:0143-6147    

DOI:10.1080/09670878909371364

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

ISSN:0143-6147    

DOI:10.1080/09670878909371365

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

ISSN:0143-6147    

DOI:10.1080/09670878909371366

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor