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Item The effects of defoliation and rootpruning on cocksfoot and perennial ryegrass and the influence of soil moisture on root initiation : a thesis presented in partial fulfilment of the requirements for the degree of Master of Agricultural Science in Field Husbandry, University of New Zealand(Massey University, 1949) Edmond, D. B.The world is short of food (1). The population of the world is unequally distributed in relation to the productive ability of the land. Countries, where an extension of the farmed area is possible, are handicapped by a lack of available labour. In general these are the countries where production has not, as yet, reached a maximum level. As labour hinders extension an endeavour must be made to utilise present farm areas in the most efficient manner possible, In this way surpluses of food may be accumulated in these countries, e.g. New Zealand, for despatch to needy areas where the consumption of food is at a low level. New Zealand produces animal products in quantity. To increase this quantity better use must be made of our chief stock food - grass. By more efficient use of our grasslands the production of our existing herds and flocks will be increased. while an increase in our animal population will be inevitable. [From Introduction]Item Seasonal root changes and their relationships to leaf production and persistency of growth in some grasses and clovers : a thesis presented in partial fulfilment of the requirements for the degree of Master of Agricultural Science in Field Husbandry at Massey University, by 550 [D.E. Yen](Massey University, 1947) Yen, D. E.The seasonal behaviour of pasture plant species is of fundamental importance to the farmer as one of the indices of value of any particular species, and the uses to which it can be put; and to the plant breeder, since it is his primary object to produce pasture plants which suit the farmer under his particular system of farming. To illustrate this point specifically, the example of the ideals aimed at in the breeding of short rotation ryegrass in New Zealand may be cited. Quoting Levy (1945), "... Italian ryegrass is a one- to two-year plant for the temporary pasture, and the true perennial ryegrass can be used widely in rotational and permanent pastures. There is, however, too large a gap between true perennial ryegrass and true Italian ryegrass, and many years of breeding and selection within these species accentuated the gap rather than reduced it." It can be seen that the short rotation system of farming, incorporating pasture leys of 3-4 years was not well served in the choice of a suitable ryegrass. Thus the plant breeding section of the Grasslands Division (Department of Scientific and Industrial Research) turned its attention towards breeding by hybridisation of perennial and Italian ryegrass, a type that would possess as far as possible the desirable qualities of these two species in combination; that is, it would combine some of the rapid establishment, high winter and early spring growth and palatability of Italian ryegrass with an appreciable degree of persistency of perennial ryegrass. Seasonal growth thus played the major part in the objectives of the resultant programme from which short rotation ryegrass was produced. Comparative trials of yields of the three grasses, perennial, Italian and short rotation ryegrasses were conducted in different localities, serving a very important purpose in providing farmers with direct information regarding the seasonal characteristics of production of the new type. These trials, which are continuing, show that short rotation ryegrass conforms largely to the objectives aimed at, so that the requirement s of the man farming under short rotation system have been met, to a great extent, by the work of the plant breeder. [From Introduction]Item An investigation into the effect of seasonal root replacement upon plant longevity in perennial ryegrass (Lolium Perenne), Italian ryegrass (L. multiflorum), tall fescue (Festuca arundinacea) and annual meadow grass (Poa annua) : a thesis presented at Massey Agricultural College in part fulfillment of the requirements for the degree of Master of Agricultural Science in the University of New Zealand(Massey University, 1955) Schwass, R. H.Any reader of the American news magazine, "Time", will know that the editors occasionally publish a "grass roots report" dealing with some current question of public interest. It takes the form of a survey of the fundamental issues involved, and attempts to assess their significance, in-so-far as those issues are known. It is a tacit recognition by a non-scientific body of opinion of the importance of the underground organs to the well-being of a plant, and that these organs are more essential, despite their hidden and inaccessible habitat, than is commonly recognized. [From Introduction]Item A study of root aphid Aploneura lentisci Pass. biology and root aphid-host interactions with perennial ryegrass/endophyte associations in New Zealand : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Entomology at Massey University, Manawatū, New Zealand(Massey University, 2019) Müller, Jana LeonieThe root aphid Aploneura lentisci Pass. is an underestimated, under-researched pasture pest likely to become more problematic in New Zealand if the environmental temperature and the frequency of water deficit stress increase, as predicted. The research presented here aimed at gaining first insights into its biology and interaction with plants and endophytes to promote future pest management research. For this purpose, root aphids were observed in model systems (in climate chambers, glasshouse or insectary; in empty microcentrifuge tubes or on diploid perennial ryegrass Lolium perenne L. plants grown on nutrient-enriched agar, with or without endophy Epichloë festucae var. lolii [Latch, M.J. Chr. & Samuels] C.W. Bacon & Schard of the AR1, AR37 or common-toxic CT strains). Apterous neonate offspring, the presumed main dispersal stage of A. lentisci, survived up to four weeks without food (median survival: 8 days). On endophyte-free, mature ryegrass kept at 17 to 21 °C, neonates developed to adults within three to four weeks and lived about two months, feeding mainly on young roots of first and second branching order. Taking into account lower outdoor temperatures, root aphids are thus likely to complete six to nine generations per year in the field. Adults produced 39 to 70 offspring over their lifetime. Presuming a similar nymphal mortality in the field as in the experiments, outdoor root aphid populations could theoretically multiply 23- to 45-fold at each generation. Root aphids raised on endophyte-infected, mature plants were shorter-lived than peers raised on endophyte-free plants. Most aphids on AR37-infected plants did not even reach reproductive maturity. The response to CT-infection was dependent on the plant genotype. Why AR1-infected plants frequently support larger root aphid populations than endophyte-free plants in the field could not be explained by the data collected, however. Root aphid feeding affected the root biomass but not the shoot biomass of perennial ryegrass in the experimental environment. This finding differed from previous reports. Furthermore, colour analyses suggested root aphid feeding could modify some leaf properties. More research will be required to confirm these findings and assess whether irrigation or fertilisation could mitigate root aphid yield losses in the field.Item The expression in soil bacteria of symbiotic genes from Rhizobium leguminosarum biovar trifolii : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Microbiology at Massey University(Massey University, 1994) Fenton, MichaelRhizobium leguminosarum biovar trifolii strain ICMP2163::Tn5 was able to spontaneously transfer its pSym to the non-nodulating Rhizobium loti soil isolate NR40 in sterile soil microcosms containing Ramiha hill soil or Ashurst silt loam soil at pH 6.0 or higher. In sterile soil microcosms at pH 6.0 containing sterile ryegrass or white clover plants the frequency of NR40 transconjugants was higher than in microcosms containing soil alone. The survival of the parent strains decreased in soil with a pH of 5.5 or less, and no transconjugant NR40 bacteria were detectable. Southern blots of the genomic digests probed with nodA DNA confirmed that transconjugant NR40 contained symbiotic genes. On artificial media strain ICMP2163::Tn5 transferred its symbiotic plasmid, by conjugation, to Sphingobacterium multivorum, an organism that can be found in soil. The transconjugant bacteria were able to nodulate white clover seedlings but were unable to fix nitrogen. Microscopic examination revealed that the root nodule structure, and bacteroid formation, were abnormal. The bacteria occupying the nodules were isolated and the total DNA extracted. The partial 16S RNA gene sequence from a transconjugant derived from a nodule was shown to be identical with that of the recipient S. multivorum. Southern blots of the genomic digests probed with nodA DNA confirmed that the transconjugant contained symbiotic genes. A Caulobacter crescentus sewage isolate was also able to induce a tumour like growth on white clover seedlings after receiving the pPN1 co-integrate plasmid from E.coli strain PN200. Eckhardt gel analysis confirmed that the transconjugant Caulobacter carried the R68.45:pSym co-integrate plasmid. Bacteroids were absent but Caulobacter cells were found in the outer two or three layers of the growth and the plant cells in this region had degenerated. Sequence data was obtained for a 260 bp fragment of the 16S rRNA gene from Sphingobacterium multivorum and Caulobacter crescentus corresponding to postions 44 to 360 on the Escherichia coli genome. A distance matrix was constructed showing the relationship between S. multivorum, C. crescentus, Rhizobium, and related bacteria and neighbor-joining was used to construct a tree. From the tree given it is concluded that the ability to carry or express symbiotic genes is not dependant on having a phylogenetic relationship with Rhizobium.Item Investigating a group of New Zealand leaders : their roots of, routes to, and routines in leadership : a ... research report ... presented in partial fulfilment of the requirements for the degree of Master of Management at Massey University(Massey University, 2004) McLeod-Jones, DavidZaleznik (1977) addressing “Development of leadership” in Managers and leaders: Are they different? states that, “The development of every person begins in the family . . . Also, beyond early childhood, the patterns of development that affect managers and leaders involve the selective influence of particular people (p.75). This leads to a position of leadership that he earlier suggested, “inevitably requires using power to influence the thoughts and actions of people” (p.67). These stages of leadership correspond with the roots of leadership, the routes to leadership, and the routines in leadership, investigated in this research project. These were drawn, with some modification, from research conducted by Sinclair and Wilson (2002) into leadership in the Australian setting. Having observed the impact of leadership, or the lack of, in both work and community settings, I was interested to investigate what led to a person becoming a leader, and what they thought they did in that role. It was only near the end of my literature review that I came across Sinclair and Wilson’s work and their use of qualitative research for investigating leadership. I have modelled my research project on theirs, to investigate the development and practises of a group of leaders in the New Zealand setting.