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    A study of the leafspot disease of lettuce caused by Stemphylium botryosum Wallr. : a thesis presented in partial fulfilment of the requirements for the degree of Master of Agricultural Science in the University of New Zealand, Massey Agricultural College
    (Massey University, 1961) Slade, Donald Arthur
    Lettuce (Lactuca stavia L) is the most important salad crop and a principal vegetable of New Zealand where in many districts it can be grown out of doors all the year round. Winter lettuce growers commonly plant from 1/2 - 5 acres of lettuce, and a good crop will cut 400 cases an acre. In late winter and early spring when other vegetables are scarce, returns to the grower from lettuce may be as high as 20/- to 60/- a case. Returns per acre from winter lettuce are therefore relatively high compared with other winter crops. The success of this crop is of major importance to the grower who commonly depends on it to cover the high winter and spring labour expenses which usually coincide with a period of low production. From season to season and even from week to week in the same season, the quality and quantity of lettuce available is a direct reflection of the prevailing weather conditions. Weather may act directly on the lettuce plant affecting its rate of maturation, appearance and plant size. Weather may also have a profound indirect effect by providing conditions conducive to disease development. It is well recognised that a disease may reach epiphytotic proportions only if weather conditions are favourable to the causual organism. [From Introduction]
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    A study of some fungal leafspot diseases of Dactylis glomerata in the Manawatu : a thesis presented in partial fulfilment of the requirements for the degree of Master of Agricultural Science in the University of New Zealand
    (Massey University, 1957) Latch, G. C. M.
    New Zealand is unique in that the entire basis of her national economy is based upon livestock-pastoral farming. Of the fortythree million acres in occupation for agricultural and pastoral purposes, seventeen and a half million are of sown pasture and about thirteen and a half million of natural grasslands. The seventeen and a half million acres of sown pasture are down in imported grasses of which approximately one half has been surface sown and the remainder sown on cultivated land with high producing English grasses. These have been selected for such qualities as leaf area and density of leaves, form of the plant, resistance to drought and many other desirable agronomic properties. Regarding the disease factor, there has been no attempt in New Zealand at breeding for resistance to disease with the exception of Blind seed disease of Ryegrass caused by Gloeotinia temulenta (Prill. et Delacr.) Wilson, Noble et Gray. [From Introduction]
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    A taxonomic study of Cercospora vitis (Lév.) Sacc., the causal organism of a leaf spot disease on grapes : a thesis ... for the degree of Masterate of Agricultural Science
    (Massey University, 1970) Harvey, Ian C.
    A leaf spot disease of grapes caused by a dematiaceous fungus is described for the first time in New Zealand. Literature on the taxonomy of the causal organism is reviewed and reveals a pleurality of binomials that have been applied to the fungus. The main features in contention are the correct basionym, symptomatology, conidium shape and degree of conidiophore compactness. These were studied in relation to the taxonomy of the causal organism and from results obtained it was finally placed in the genus Cercospora, where the binomial becomes C. vitis; the legitimate specific epithet for the fungus. Cultural studies of the pathogen provided further supporting evidence for placement in the genus Cercospora. An apparatus for photomicrographically recording conidium ontogeny and spore germination patterns of filimentous fungi is described. Classification schemes of the Fungi Imperfecti are reviewed and all were found to have certain shortcomings with respect to the classification of the causal organism. A proposed alternative scheme is outlined. The disease does not become manifest until late in the growing season and hyphal swellings in the stomata (stomatopodia) are found to constitute the form in which the pathogen persists during a latent infection period. A disease cycle is synthesised from results of glasshouse infection experiments, field observations, and reports from the literature,
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    Identity, taxonomy and seed-borne aspects of the gray leaf spot organism on blue lupin : a thesis submitted in partial fulfilment of the requirements for the degree Master of Agricultural Science at Massey University
    (Massey University, 1968) Tate, Kenneth Gregory
    While conducting studies in the Manawatu on the brown spot disease of blue lupins 1/ caused by Pleiochaeta setosa (Kirchn.) Hughes, Milne (1964) frequently encountered a Stemphylium disease characterised by necrotic lesions on leaves, stems and pods. A disease caused by a species of this genus had not previously been reported on blue lupins in New Zealand, but in the United States of America Wells, Forbes, Webb and Edwardson (1956) described two previously unrecognised diseases on this host, namely "little leaf spot" caused by Stemphylium botryosum Wallroth and "gray leaf spot" caused by S. solani Weber. Milne considered his isolates to be S• botryosum but was confused by the symptoms being typical of those recorded for S.solani (gray leaf spot). He did not pursue the matter further and at the completion of his studies on P• setosa there remained the unresolved question of the identity of the Stemphylium species present on blue lupin in the Manawatu. [From Introduction]