Use of a non-mist propagation system to vegetatively propagate 12 E. grandis X E. Camadulensis hybrid clones

Abstract

Eucalyp tu s t r ees h ave p r ove d t o b e a popul a r spec i es fo r f a rm fores tr y, h owever, th e ir v e g et a tive p r opagatio n has n ot been op t i m ised d u e t o i n here ntl y poor rooting in so m e of the h y brid c lones, co u p l ed wit h t h e hig h co s t of i n frastruc tu re u s ed to p r op a gate them i n mist prop a gators, maki n g t h e tec hn o l o g y u naffo r dab l e by t he r u ra l poor. A se r i es o f nu r se r y expe r ime nt s was ca rri ed o ut t o assess t he ef f ec t s of rooti n g m edi um ( sa n d a nd c l ay s ubsoil, m ixed in t he f ol l owing r atios 1:0, 1 : 1, 1 : 2, 0 : 1 and 2: 1 re s pecti ve ly by vo lum e ) , a uxin c oncentration (0 % , 0 . 6 % , 0 . 8 % , a nd 1 % I BA w / w) and le a f a r ea (0, 30, 40, 50 , 6 0 , 8 0 a nd 100cm 2 ) on rooting of ju v enile cuttings of EucaL y ptus grandis x c amadul e ns is (EG C ) hybrids in a non mist propaga ti on sys t e m i n o r de r t o dev e l o p a c h eap p r opagation protoc o l for Eucalyptus hyb r id c l o n es in Kenya . R es ult s s h owed n o s ignifi c ance differ e nce (p=0 . 103, ANOYA) in rooting among different EGC hyb r ids and I B A conc e nt r a tion . H o we v er , r oo ting was o b s erved in cu t tings wi th ou t app l i c a t ion of IB A , with hi g he s t rooting in c l ay s ub s oil (65 . 0 % ) . T h e overa ll effec t of p r opaga t io n m ed i a was significant (p<O.OI, ANOYA) on rooting and shooti n g pe r ce nt age, w i t h sa nd so il h av in g th e l eas t m ea n rooting (12 . 5 % ) a nd shooting percentage (23. 0 %) a mong d i ffe r en t EGC h yb r ids , comp a red to c l ay s ub so il h av in g the highest mean rooting (59 . 9 % ) a n d s h ooti n g pe r ce nt age (81 . 9 % ). L ea f a re a h a d a pronounced effect o n roo tin g a n d s h oo tin g pe r ce nt age of EGC hybrids , w i t h 100cm 2 g iving t h e h ig h es t roo tin g ( 65 . 9%) a nd s h oo tin g ( 78. 1 % ). O c m 2 gave t h e lowes t roo t ing (7 . 5 % ) a nd shooting pe r cen t a g e (12 . 7 % ). Th ese res ult s show that EGC hybrid s ca n be s ucce s sfully prop a gated i n a non-mi s t p r opaga t io n sys t e m . Clay s ub so il, i n combin a ti o n w ith a l ea f are a of 10 0 cm 2 a nd no appli c at i o n of IBA , may be r ecomm e nded f o r use in thi s propagatio n syste m .