COMPARATIVE METHODS OF APPLICATION OF WILD PLANT PARTS ON GROWTH AND IN THE CONTROL OF ROOT ROT FUNGI OF LEGUMINOUS CROPS

摘要

Aphids cause heavy yield losses to Brassicaceous species by affecting various physiological and biochemical processesincluding photosynthesis. In the present study, seasonal activity of aphid population and its impact on some brassicaceousspecies was assessed. Three brassicaceous species (Brassica campestris, Brassica carinata, Eruca sativa) were grown infield following standard agricultural practices. Plants of control plots retained aphid free by insecticide spray, whereastreatment plots were freely allowed for aphid infestation. There was also intermediate treatment of partial aphid infestationwhere insecticidal spray was applied two times. Peak populations of both aphid species were observed in the 2nd week ofMarch during which plant photosynthetic attributes were recorded. At the time of maturity, yield attributes were alsorecorded. From the results, it is obvious that application of insecticide significantly reduced the aphid populations on thethree brassicaceous species and enhanced the crop yield. Yield losses due to aphid infestation were maximal in Brassicacampestris followed by B. carinata whereas it was minimal in Eruca sativa. Yield losses in Brassica campestris and B.carinata were due to reduction in number of pods per plant, number of seeds per pod and size of seeds, whereas yield lossesdue to aphid infestation in Eruca sativa was mainly attributed to reduction in number of pods per plant. Althoughinsecticidal spray reduced the aphid population and increased growth and productivity of all brassicaceous species, it did notchange photosynthetic capacity of all plants except in Eruca sativa. Moreover, growth and yield reduction was notassociated with stomatal factors of photosynthesis. Chlorophyll contents measured as SPAD values were reduced due toaphid infestation which is positively associated with yield reduction. Insecticidal spray increased chlorophyll contents inthese three brassicaceous species by reducing aphid population. Application of insecticidal spray two times caused loweraphid infestation in brassicaceous species but it could not recover total yield losses. From these results, it is suggested thataphid infestation induced growth and yield reduction in the three brassicaceous species was due to some non-stomatalfactors or due to alteration in metabolism of chloroplast. To affirm this, further research is needed.