摘要:

Five fungicides, 2 antibiotics and 2 combinations of fungicides and antibiotics were evaluated against incidence of bacterial and fungal diseases ofPiper betleL. Cv. ‘Desawari’. Copper oxychloride 50 WP (Blitox‐50) at 0.25% at 15 days interval was most effective against mortality caused byPhytophthora parasiticavar.piperinaDastur; whereas 0.25% Copper oxychloride 50 WP with 500 ppm streptocycline was best against leaf spots caused byXanthomonas campestrispv.betlicolaDye. andColletotrichum capsiciSyd. (Butler & Bisby). Other formulations viz., Carbendazim (Bavistin), Trideomorph (Calixin), Mancozeb (DithaneM‐45), Copper oxychloride 50 WP (Kilex), Paushamycin and Streptocycline were only next to the copper oxychloride 50 WP (Blitox‐50) or its combination with streptocycline.

ISSN:0143-6147    

DOI:10.1080/09670878809371263

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

A survey was conducted of 21 estates and cocoa germplasm collections at locations representative of the cocoa growing areas of Trinidad to determine the current status of witches’ broom disease of cocoa on the island. The disease caused byCrinipellis perniciosa(Stahel) Singer, was prevalent at all sites investigated. Its incidence was however considerably less than that reported in the 1940s and 1950s. The widespread cultivation of resistant cocoa genotypes appeared to be the dominant factor responsible for the reduced disease level. It was also observed that recommended management practices such as fertilizer application, regular weeding and shade regulation, all conducive to vigorous tree growth, were neglected on most estates. Consequently, the heavily shaded crop does not flush or flower so intensely as to provide an abundant supply of susceptible tissues for the pathogen which only attacks meristematic tissues. Evidence indicating the probable absence of the severe pathotype ofC. perniciosareported from Ecuador and Colombia was also noted.

ISSN:0143-6147    

DOI:10.1080/09670878809371264

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

As part of a continuing programme to aid in the development of new acaricides, the efficacy in the field of four different pour‐on formulations was tested against four economically important tick species in Kenya. Synthetic pyrethroids flumethrin2, cypermethrin (mixed isomers)3, and alpha cypermethrin4were compared together with an organophosphate, phosmet5. All the acaricides were applied along the dorsal midline of the animals except where Porect was applied onto the ears, neck and face of the animals as an alternative treatment. Bayticol was significantly more effective than all the others tested (P <0.05) for the duration of the trial of 14 days and would be of immense benefit to farmers who are dipping once or even twice a week and still experience losses fromTheileria parvainfection or East Coast Fever (ECF). Porect, SF06666 and SF06646 were found inadequate to be used in situations where susceptible cattle are reared in ECF endemic areas. However, they can be used where farmers rear resistant cattle and where the priority is to reduce tick worry without trekking animals for long distances to the dip. SF06666 had poor control over body ticks particularly theAmblyornmaspecies. Porect at special application rates to the ears, face and neck is too cumbersome to be practicable. There was a significant rub‐off effect on to the synthetic pyrethroid control animals, especially Bayticol, which contributed to the low numbers of total ticks in the controls relative to total ticks pre‐treatment.

ISSN:0143-6147    

DOI:10.1080/09670878809371265

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

In an insect pests survey of soybean during 1977–1980, in the rabi and kharif seasons, 14 species were more, and 33 species less abundant, representing 19 families under seven orders. The occurrence ofAphisspp.,Atractomorphaspp.,Spilosoma obliquaW.,Monolepta signataOlv.,Nezara viridulaL.,Myllocerusspp.,Riptortusspp., and Jassids were most notable.

ISSN:0143-6147    

DOI:10.1080/09670878809371266

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

Studies on the seasonal abundance ofEurytomasp. a parasitoid on okra petiole maggot,Melanagromyza hibisciSpencer were conducted for one year. Per cent parasitism ranged from 10 to 68 during the study period. However, there was no significant relationship between percentage parasitism on host density. Data further revealed that parasitoid response to host density was weak.

ISSN:0143-6147    

DOI:10.1080/09670878809371267

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

Seeds of nine varieties of chickpea,Cicer arietinumL. were treated with different dose levels of mustard oil for assessing the efficacy of the oil against the attack of chickpea bruchidCallosobruchus chinensis.The treated seeds after two years of storage were subjected to germination tests to find out any deterrent effect of oil on the germination. Oil treatments could not impart protection to any of the ILC‐genotypes. The varieties CM‐72, NEC‐138–2, C‐141, HG‐202–6–1 and ICCL‐11514 were completely protected for five months at 10 ml oil/kg seed. Significant interaction among the genotypes was found. Maximum bruchid emergence was noted in ILC‐varieties. Oil treatment at 10 ml/kg seeds caused 100% germination inhibition in all the ILC‐genotypes.

ISSN:0143-6147    

DOI:10.1080/09670878809371268

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

A method was devised for estimating large populations of cowpea aphidAphis craccivoraKoch (Hemiptera: Aphididae) on cowpea. The densities of the aphid on stem, leaves and pod were first estimated in the laboratory for use in the field later. The densities were estimated in three arbitrary classes of infestation, viz. heavy, medium and low, determined visually based on the intensity of colonization. The densities of the aphid per cm2on stems were 108.50, 49.77 and 2503, while on pods they were 80.68, 44.46 and 23.20, in the three classes of infestation respectively. The aphid did not show any preference for the thickness of stems whereas young pods were preferred to old pods for colonization. The mean aphid densities on leaflets of topmost leaves were 62.10, 36–35 and 18–50, while on leaflets of top 2nd and 3rd leaves they were 124–60, 69–35 and 38.20, in the three infestation classes respectively. Comparisons made between the aphid densities on different parts of cowpea plant showed that the aphid colonized them in descending order of preference as stem > pod > top most leaf > top 2nd and 3rd leaves.

ISSN:0143-6147    

DOI:10.1080/09670878809371269

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

The seasonal occurrence of gram pod borer,Heliothis armigeraHb. in sorghum during cropping periods was studied. The incidence ofH. armigeralarvae was highest between March and June, 1984. This gradually decreased between July and October, 1984 and was lowest between January and March, 1985. Larval counts were found to be higher on the cultivar CSH 5 than K‐tall. The main crop of first two cropping seasons harboured more larvae than the ratoon crops while in third cropping period there was no significant difference.

ISSN:0143-6147    

DOI:10.1080/09670878809371270

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

This unarticle reviews the progress made in the study of resistance in eggplant to shoot and fruit borer. Resistance in the cultivars screened exists at a low level. Screening of large numbers of cultivars and breeding lines with broad genetic base is emphasized. The possibility of transferring resistance from wild relatives needs thorough investigation. To look for antixenosis due to the morphology of the plant or tolerance to withstand pest attack would be desirable. The use of tolerant cultivars with less insecticide is suggested as the most acceptable control method.

ISSN:0143-6147    

DOI:10.1080/09670878809371271

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

The millet head worm, the larval stage of the Noctuidae mothRaghuva albipunctellahas become the most serious pest of millet in the Sudan. The adults emerge seven weeks after the first effective rainstorm of over 30 mm, which coincides with the heading of most millet varieties. The female lays eggs on newly emerged millet heads. Larvae enter the head and mine within the head, eating the bases of the flowers pushing up the severed florets in a characteristic spiral trace. Long‐maturing varieties and delayed planting are both effective in reducing the incidence of infestation but are impractical in the environmental conditions in Western Sudan. Varietal tolerance has been identified and should be used as one aspect of control. Synthetic pyrethroids reduce incidence but do not significantly increase yield. The use of triple superphosphate fertilizer increases yield and reduces the incidence of the head worm by reducing the time interval from planting to heading and resulting in the emergence of the main heads prior to the emergence of the pest.

ISSN:0143-6147    

DOI:10.1080/09670878809371272

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor