Report 05. Microsymbiont colonization and seedling development as influenced by inoculation method : Rhizobium and Frankia

Abstract

This investigation tested the various methods used in Haitian nurseries for inoculating tree seedlings with nitrogen-fixing organisms. Acacia, leucaena, and frene were inoculated with Rhizobium powder by oil-coat, water-coat, water-drench, and gum-arabic methods, and by soil. Casuarina was inoculated with Frankia powder by water-drench and salt-shaker methods, and by soil. Variables tested were seedling height, root collar diameter, and numbers of total and red nodules per tree. Only a few differences were seen among the inoculation methods tested on acacia, casuarina, and leucaena. When differences were found, they were not large. More differences may have been found if the inoculum used on these species had been better. For these species, only about two nodules per tree were found on the inoculated seedlings. This low number indicates low viability of the inoculum. The inoculum strain used on frene appeared to be good, however, and produced about 21 nodules per inoculated tree. Inoculation by soil produced only 5.4 nodules per tree, not different from the controls at 3.4 per tree. Other variables were not affected significantly. The major conclusions of this study are that inoculum must be viable to produce nodules, but that when the inoculum is viable, any inoculation method may be used without compromising nodulation or seedling development. Soil can also be used as a inoculum source, but it must be recently gathered and probably should be used at a ratio of about one part soil to two parts Gromix.

Esperyans sa-a te fèt pou eseye kèk metòd inokilasyon ki kapab sevi pepinyeris pou inokile ti pyebwa ak Rizobyom ou Frankya. Nou sevi ak plizyè metòd. Nou mouye grenn yo ak lwil kwizin, ak dlo, e ak gom arabik. Nou wouze grenn yo ak yon melanj dlo e poud Rizobyom. Nou pran tè ki gen Rizobyom landan-l e nou melanje-l ak Gromiks. Tout metòd sa yo te sevi pou inokile akasya, lesena, epi frèn. Pou Frankya, nou sevi ak metòd dlo wouze, simen poud, ak Frankya melanje nan tè pou inokile kazawarina. Nou mezire wotè ak lage chak plantil, epi nou konte tout ti boul ak ti boul wouj chak plantil pouse sou rasin li. Nou prèske pat jwenn diferans ent metòd inokilasyon nou te esaye sou akasya, kazwarina, oubyen lesena. Lè nou te jwenn yon diferans, li pat gwo. Petet nou ta ka jwenn plis diferans si inokilan yo te pi bon. Nou jwenn de ti boul nan chak plantil inokile. Yon ti valè konsa vle di inokilan sa yo pat bon. Kalite inokilan ki te sevi sou frèn te byèn mache. Li fè plis pase vèn ti boul pouse nan chak plantil, un kantite ti boul prèske egal kantite ti boul nan plantil pa inokile yo. Metòd inokilasyon pa fè gwo diferans ent lot mezi yo. Avek esperyans sa-a, nou wè anko fok gen bon inokilan pou fè ti boul sou rasin plantil pouse. Pepinyeris kapab sevi ak nenpòt metòd inokilasyon lè inokilan-an bon. Pepinyeris kapab sevi ak tè tankou sous inokilan, men fok tè-a frè. Li kap melanje you bokit tè ak chak de bokit Gromiks.