Fungal alkaloid occurrence during seedling establishment and early growth in Lolium perenne seedlings infected with Epichloë festucae var. lolii and the influence of adult Argentine stem weevil (Listronotus bonariensis) feeding on alkaloid concentrations : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science (MSc) in Agriculture Science at Massey University, Palmerston North, New Zealand

Fungal endophytes of the genus Epichloë often form stable, symbiotic, and mutualistic relationships with grasses of the Pooideae, including perennial ryegrass (Lolium perenne L.). The endophyte provides various benefits to its grass host, through the production of secondary metabolites, which are exploited in New Zealands pastoral agriculture systems. The endophyte can give its host grass an ecological advantage in certain challenging environments, such as during seedling establishment, where young plants are especially vulnerable to insect predation, such as feeding by adult Argentine stem weevil (ASW, Listronotus bonariensis). This thesis focuses on understanding the alkaloid concentrations that occur in endophyte-infected perennial ryegrass seedlings during the early establishment phase. A glasshouse experiment was conducted in which fungal alkaloid concentrations (peramine, lolitrem B, ergovaline, and epoxy-janthitrems) were measured in perennial ryegrass seedlings infected with Epichloë festucae var. lolii strains AR1, AR37, NEA2, and NZCT for 69 days after sowing. From the data it is inferred that an initial translocation of alkaloids stored in seed during maturation into the developing shoot of the germinating seedling occurs, followed by a period of alkaloid dilution due to seedling expansion, and finally production of newly metabolised alkaloids in the plant. Alkaloid concentration were found to peak in 8–10 day old seedlings, giving the seedling a “kick start” in protection of the emerging seedling from adult ASW feeding during the first 11 days after sowing. The influence of adult ASW feeding on alkaloid concentrations in endophyte-infected perennial ryegrass seedlings was also tested. The study demonstrated that adult ASW feeding can influence alkaloid production, although peramine, the main alkaloid responsible for ASW deterrence was not significantly affected. Findings from this thesis improve understanding of the role of fungal alkaloids in endophyte-infected perennial ryegrass seedlings during establishment, and help explain results from earlier studies describing seedling susceptibility to adult ASW

Tobacco seedling production

Production of a high quality crop of tobacco begins in the seedbed, and it is therefore essential that the utmost care and attention be given to this stage of the crop. In general, it has been found that it is better to grow one\u27s own seedlings, rather than rely on those from an outside source, thus ensuring that strong, healthy seedlings of the correct variety and strain are available at the time of transplanting

Modelling production cost and financial return of forest reproduction materials in relation to nursery size

Forestry seedling production in the Philippines takes place in government, industrial, smallholder and community nurseries. While it might be expected that seedling production costs decrease as nursery size increases, surveys have revealed that nursery operators have little knowledge about their seedling production costs. To overcome this lack of information, financial models have been developed in the ACIAR seedling enhancement project for forestry nurseries of a range of sizes, for nurseries using durable infrastructure, producing seedlings of indigenous tree species, and following best management practices in seedling production. These reveal that the cost per seedling is high for small nurseries, but becomes relatively constant at about $0.35 US per seedling for annual production above about 25,000 seedlings a year. The need is identified for further research on nursery costs (particularly in relation to labour costs, source and type of germplasm), market demand for seedlings from nurseries accredited with adopting best management practice, and benefits of vertical and horizontal integration of forestry nurseries

Seed factors involved in early seedling establishment of Festuca arundinacea (tall fescue) : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Plant Biology and Biotechnology at Massey University, New Zealand

New Zealand pastures are commonly based on vigorously growing Lolium (ryegrass) species. In many situations, however, it is often advantageous to combine the vigorous qualities of Lolium species with the versatility of other species such as Festuca arundinacea (tall fescue) to result in a pasture which is high in quality all year. F. arundinacea, however, has poor seedling vigour which places it at a competitive disadvantage when sown with Lolium. During seedling establishment, the seedling is dependent upon the food reserves present in the seed. The nature and amount of these reserves and the ability of the seed to mobilise them are therefore likely to have an affect on seedling perfonnance. While much knowledge exists about the processes involved in seed reserve mobilisation in some cereals, little information is available for pasture grasses. An in depth investigation of the behaviour of one seed lot of F. arundinacea was undertaken in order to gain a more detailed understanding of germination, reserve mobilisation and establishment processes in pasture grasses and how they relate to the processes of seedling growth. Comparisons between this species and Lolium multiflorum (Italian ryegrass) were undertaken throughout the study. Germination and seedling growth of the F. arundinacea seed lot was found to be heterogenous and slower than in L. multiflorum due to later radicle emergence. Mobilisation of reserves and the onset of α-amylase activity correlated well with the utilisation of reserves in L. multiflorum. In both prechilled and non prechilled F. arundinacea seeds, however, anomalies were identified in the process which indicated that reserve mobilisation was less tightly coupled to seedling growth in F. arundinacea. Reciprocal plot analyses indicated that the beneficial effects of prechilling in most seeds of the F. arundinacea seed lot were not related to residual dormancy but were a thermal time benefit. It appears prechilling was allowing rate limiting steps in embryo growth to be advanced before visible germination. Apart from this, no real differences were detected in the way the two species mobilised reserves. Differences in the appearance of α-amylase isoenzymes of F. arundinacea at different times during germination indicated that gene expression may be under some complex differential control mechanisms during germination and reserve mobilisation. Prechilling was not found to change the spectrum of isoenzymes, but merely to advance the time-course in which different isoenzymes appeared. There were also distinct differences in α-amylase isoenzyme patterns between F. arundinacea and L. multiflorum, and also wheat. Preliminary studies indicated that exogenous gibberellic acid was more effective in promoting α-amylase production in L. multiflorum than in F. arundinacea. However, α-amylase production in F. arundinacea was more susceptible to promotion by prechilling. This study has identified a wide range of variables impacting on germination and seedling establishment in F. arundinacea. This, together with the lack of previous detailed studies on grass seed germination and seedling growth and the lack of literature on F. arundinacea germination in particular, highlights the enormity of the task ahead of extending key areas of this study to different seed lots and species

Waratah theft in Brisbane Water National Park - an analysis of the blue paint poaching reduction program

The flowers of Waratahs, Telopea speciosissima (family Proteaceae) are regularly harvested illegally from natural bushland, particularly close to urban areas such as the New South Wales Central Coast. The removal of Waratah blooms from the wild may have implications for the long-term survival of local populations because of the interaction between wildfire events, subsequent flowering and limited seedling recruitment opportunities. To reduce the incidence of theft, blue acrylic paint was applied to blooms to reduce their commercial value. The painting of blooms in 2004 did not significantly reduce the incidence of wildflower theft when compared to unpainted blooms, but overall losses were lower (27%) than in 2003 (33%). However, painting of blooms had a deleterious affect on fruit production on plants with multiple heads with painted blooms having significantly reduced fruit set compared to unpainted blooms. Painting of blooms had no significant effect on seed quality (seed production per fruit, seed germination or seedling vigour) when compared to unpainted blooms. The painting of Waratah blooms to reduce theft was relatively ineffective and decreased fruit production. Alternative strategies should be considered to reduce wildflower theft in the area

Effect of Seedling Production and Long-Distance Transportation Planning Strategies on Transportation Costs of a Nursery Company

In Finland, the number of nurseries has been decreasing year by year, and it seems probable that in the near future this trend will continue. It can be assumed that greater economies of scale could also be achieved in Finnish seedling production by enlarging the size of production units [9, 10] . The management strategies used by a nursery company for long-distance seedling transportation were compared with different allocations of seedling production among nurseries. To determine the optimal transportation costs in different strategies for seedling production and planning of long-distance transportation, linear programming (LP) was applied. To manage spatial information, a geographical information system (GIS) was used. The current development towards seedling transportation managed by nursery companies seems to have marked advantages in the cost-effectiveness of transportation. The relative improvement in cost-effectiveness caused by centralized transportation strategy (CTS) compared to decentralized transportation strategy (DTS), which is the mostly used strategy in seedling transportation planning in Finland, varied from 13.0% to 36.5%, depending on the number of nurseries and the degree of specialization of production among them. These results will be useful for nursery companies and forest owners' associations (FOAs) when they evaluate the cost effects of production allocation, product specialization and systems of transportation management

The assessment of the use of eco-friendly nets to ensure sustainable cabbage seedling production in Africa

High seed cost accompanied by poor germination and seedling performance renders cabbage nursery and field production enterprises unsustainable to many small-scale growers in tropical and sub-tropical countries. In most nurseries, adverse ecological conditions and pest damage are among the major factors responsible for poor seedling performance. The objective of this study was to test the potential use of eco-friendly net (EFN) covers as a low cost technology for sustainable cabbage seedling production. The study was a two-season experiment conducted using a randomized complete block design with five replications and two treatments. Treatments were: the standard open field transplant production (control) and transplant production under 0.4 mm mesh polyethylene net covering. EFN covering increased both temperature and relative humidity, enhanced seedling growth and reduced insect pest damage. Seed germination and seedling emergence were under the net covering earlier. Higher seed germination and seedling survival were recorded under the EFN treatment, indicating a potential for reducing the seed requirement per unit area of cabbage production. Seedlings grown under the nets had higher stomatal conductance and leaf chlorophyll content; furthermore, they grew taller, with more leaves within a shorter period of time compared to the control seedlings. The use of EFN in cabbage nurseries offers a sustainable technology for enhancing seedling performance by reducing pest infestation, thereby lowering production cost and improving the grower's income. (Résumé d'auteur

ESTIMATING THE ECONOMIC GAINS FROM LARGER TOMATO TRANSPLANT CELL SIZES

This paper examines the costs and economic benefits of utilizing larger seedling transplant in commercial vegetable production. Larger transplants have been shown to mature earlier and yield more premium graded fruit. Offsetting these benefits is the increased cost of producing larger transplants, primarily from reducing the capacity of a transplant house.Crop Production/Industries,

Impact of forest management regimes on ligneous regeneration in the Sudanian savanna of Burkina Faso

Annual early fire, selective tree cutting and grazing exclusion are currently used to manage the State forests of the Sudanian savanna of Burkina Faso, West Africa. Such prescriptions, however, are not based on experimental evidence. The long-term effects of such management on seedlings and saplings and the germination of selected tree species are discussed. Seedling quality attributes are also assessed. Studies over a 10-year period examined the effects of the three management regimes on species richness and population density. Burkea africana Kook, f., Detarium microcarpum Guill. et Perr., Entada africana Guill. et Perr., and Pterocarpus erinaceus Poir. seed germination was tested for different temperatures, light conditions, dry heat treatments and scarification methods. The quality of Acacia macrostachya Reichenb.ex DC. and P. erinaceus planting stock was evaluated in relation to nursery production period; field performance was assessed with and without watering. Fire, grazing, and selective tree cutting acted independently on sapling and seedling population dynamics. Early fire reduced sapling recruitment; moderate grazing had no significant effect. Although the overall seedling population density was not affected by any of the treatments, fire and grazing had strong effects on single-stemmed seedling density. Ordination using Principal Component Analysis of the seedling population data revealed species-specific responses to treatments, in particular an increase of lianas compared to other species. D. microcarpum and E. africana seeds did not exhibit dormancy. Exposing B. africana seeds to 95-97% sulphuric acid for 15–20 minutes broke their physical dormancy. All seeds tested were neutrally photoblastic, with an optimal germination temperature of 25–35 oC. E. africana, however, germinated over a wider temperature range. P. erinaceus seeds did not tolerate heat shock; while D. microcarpum and E. africana seeds responded positively at low intensity. Eighteen months after outplanting, survival and growth of Acacia macrostachya and Pterocarpus erinaceus seedlings were not affected by their initial size. Drought and non-drought factors affected seedling survival. Performance of P. erinaceus seedlings could be predicted from initial root collar diameter; more data will be required to build a reliable model. This thesis recommends the use of annual early fire as a forest management tool to be continued if timing, weather conditions and other factors affecting fire intensity are given due consideration. Moderate level of grazing does not affect seedling and sapling recruitment. The current prohibition on grazing State forests may need revision to allow multiple-use management. The low seedling density of socio-economically valuable species indicates that natural regeneration could be supplemented by planting high quality seedlings

P. juliflora management at the brazilian Northeast.

Prosopis juliflora management at the brazilian Northeast: seedling production methods: seed extraction, sowing, seedling quality, seedling produced by vegetative propagation, planting techniques, irrigated planting, in situ rainwater catchment; spacing; intercropping; fertilization; cultural treatments; pests and disease; pruning; regeneration