Studies on growth , dry matter production and nutrients accumulation in Pinus Caribesa mor seedling as influenced by mycorrhizal inoculation

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University of Dar es Salaam
The aim of the study was to determine the range of the mycorrhizal fungi in pine plantations in Tanzania and study thair biology under nursery conditions* The study involwad a aurvoy of nycorrhizal fungi their isolation in pinus culture, and studies on raycorrhizae aynthaaizad with Pinus caribaea Survey of octowyccrrhizal fungi use node in 10 pine plantation and too arboreta. Characteristic taorphoicny of nycorrhizaa were observed and isolations were attempted using well established procedures modified according to detected fungal requirements and chemical availability . Over 25 species of fungi known to form aycorrhizae aith pines were identified. The main species were Tholcphora faricacrle, Sclcrodoraa dictyoaporms Suilus, luteus granulates, S. sibiricus, tyooperdon parlotura and Rhizopogon luteolus. The fungi seems to be well adapted to highland conditions but did not develop well under the conditions of Tanzania's hot, dry, coastal plain . Isolation of fungal sysmbionts in pure culture from mycorrhiae use possible with rhizopogon, lutcolus and Sclcrodoraa dictyoaporus only. These species and suillus granuletus and lycopordon peristum were isolated fromfungal aporocaps. Other fungi were not successfully isolated in pure culture . Synthesis of octosycorrhizes in pinus caribase was demonstrated with mycelial and basidispore inocule of thelephora terrestris and scleroderms dictyosporus Inoculation of Pinus caribaea aas also undertaken with Rhizapogon lutcolus selected on the basis of the ncrphology of infected pine rootlets. Thelophora tarroatria baaidioepcrcs formed atycorrhizea between pH 5.5 to 7 .4. Mycorrhizal formation was inhibited at pH 4.3 and pH 8.7. Under similar conditions, myccrrhizal formation by basidispores was inhibited by the fungicide "Perenox" at a fungicide concentration of 5 000 ppm or above. In fumigated soils, nycorrhizaa forced even at Paradox concentrations up to 7 500 ppm. Detailed studies on nutrient uptake in nursery seedlings showed superiority of mycorrhizal seedlings in the total uptake of nitrogen phosphorus, potassium calcium, magnesium and zinc over uninoculated controls However the concentrations of nitrogen and potassium were always lower in Inoculated seedlings compered to uninoculated ones due to growth dilutions. The concentration of calcium, magnesium, and zinc was not influenced by inoculation but phosphorus was consistently more abundant per unit weight in inoculated seedlings than the controls. Juvenile trachoid lengths in Pinus caribaea seedlings was significantly increased by inoculation with Rhizopagon lutcolus. This positive relation was improved by soil fumigation and fertilization with UPK. Soil fumigation and NPK fertilization improved the growth and nutriant status of Pinus caribaoa seedlings but ferlilization progressively ratarded mycorrhizal formation. KPK fertilizer progressively reduced soil pH and Increased both exchangeable potassium and available phosphorus. The increased exchangeable potassium resulted luxury consumption and retarded root growth. The increased soil acidity retarded magnesium uptake. Comparison between inocumulated and uninoculated seedlings in both eseptically and nursery raised pinus carribase seedlings showed mycorrhizal seedlings to the more robust healthy and superior in heath and dry matter production.Recommendation are made for further studies of heat tolerant mycorrhizal fungi such as pisolithus tinctorius and conocucum graniforms which might be more suitable for the hot lowland plains. The interaction of these fungi and fertilizer regimes need further studies in order to develop more effecint nursery practices.
Available in print form, East Africana Collection, Dr. Wilbert Chagula Library, Class mark (THS EAF QK604.M21
Mycorrhizal,, Pinus, Caribaea, Diseases and pests
Maghembe, J A ()Studies on growth , dry matter production and nutrients accumulation in Pinus Caribesa mor seedling as influenced by mycorrhizal inoculation,Doctoral dissertation, University of Dar es Salaam.