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    The development of fermented pea protein-coconut milk beverage : a thesis submitted in partial fulfilment of the requirement for the degree of Master of Food Technology, Massey University, Albany, New Zealand
    (Massey University, 2019) Qu, Weidi
    Most commercially available probiotic products are dairy-based and are associated with consumer health challenges such as lactose intolerance and allergenicity due to milk proteins. Therefore, a strong consumer interest in searching for alternative products and ingredients that can deliver similar health benefits to dairy-based products. Plant protein is an important nutrient for the normal growth and functioning of the human body. Pea protein is of interest to food manufacturers due to its high nutritive value. However, it is characterised by a strong off-flavour (beany flavour) making it difficult to formulate into acceptable consumer food products. The main aim of this study was to reduce the beany off-flavour of commercial pea protein powder intended for the production of an organic fermented pea protein-coconut milk beverage. This research was conducted in three main phases. In Phase 1, salt extraction and isoelectric precipitation methods were used to further purify commercial pea protein powder (Roquette S85F, France). After purification, the yellow commercial pea protein powder (b* = 16.32±0.09) had transformed into a white pea protein paste (b* = 6.86±0.12). Phase 2 investigated the reduction of the beany off-flavour by fermentation of a novel fermented pea protein-coconut milk beverage. In this phase, the refined pea protein paste (phase 1) was added to organic coconut milk (Ceres Organics, Auckland) and then fermented by a mixed lactic culture (VEGE 053 LYO). The single factor test and orthogonal experimental design were used to determine the optimum fermentation conditions of the fermented pea protein-coconut milk beverage. In these experiments, three fermentation temperatures (37 ℃, 40 ℃, 43 ℃) with three protein concentrations (3%, 5%, 7%, w /v) and three fermentation times (8, 10 and 12 h) were used to conduct nine experimental treatments (formulations). The three best fermented beverages were selected based on viable cell counts (VCCs) and sensory evaluation by a semi-trained sensory panel (n=18). These three best samples were further evaluated by a consumer sensory panel (n=90). The fermented beverage containing 3% pea protein and fermented at 40 °C /8 h was evaluated as the best product by the consumer sensory panelists. The final selected formulation had the highest viable cell counts (8.78±0.21 log CFU /mL) and overall mean sensory acceptability scores (6.2±0.50). Other parameters determined in the final formulation of the fermented beverage were pH, titratable acidity (T.A.), colour and crude protein. During fermentation for 8 h, the pH decreased from 6.15±0.13 to 4.29±0.02, while the T.A. increased from 0.09%±0.01 to 0.52%±0.03. Colour changed significantly (p<0.01), whereas there was no significant (p>0.05) difference in the protein content of the fermented pea protein-coconut milk beverage during fermentation. In the third phase, the stability of the fermented beverage during storage (4 °C) for 21 days, was determined by measuring pH and colour as well as the analysis of protein and sensory characteristics. A semi-trained sensory panel (n=15) evaluated the fresh and stored beverage for various sensory characteristics including overall acceptance using the 9-point hedonic scale. During storage of the beverage, the pH, titratable acidity, cell counts and colour changed significantly (p<0.05). By the end of storage, the pH had decreased from 4.43±0.03 to 4.38±0.02 (p<0.05), while T.A. increased slightly. The sensory characteristics were stable during storage. Despite the changes in the physical-chemical characteristics of the fermented beverage, the product was still found to be acceptable by a semi-trained sensory panel following storage for 21 days.
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    Effects of high temperature on pea (Pisum sativum) seed quality and attributed traits : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science, in Plant Breeding at Massey University, Manawatu, New Zealand
    (Massey University, 2018) Atung, Cyril Kolese
    The experiment was set up in a randomised complete block design with four replicates and two pea cultivars (Greenfeast vs. Snow pea), at two different temperature regimes (25/15-35/25°C and 25/15°C). The objective of this study is to investigate the effect of high temperature on seed quality, germination and evaluates the changes in the protein and total soluble sugar content of pea seeds in response to high temperature. The high temperature had significantly reduced flower number, flower accumulation number, pod number and pod accumulation number. The pod number of Greenfeast was highest at day 104.10 at 15/15°C than Greenfeast at 15/25-35/25°C whereas Snow pea pod number was significantly higher at day 91.97 at 25/15°C than at 25/15-35/25°C and the rate of increase was higher for the Greenfeast at 25/15°C, followed by Snow pea t 25/15-35/25°C with the highest correlation (R2=0.73). The pod accumulation rate (K) for Greenfeast was lower than other treatments, with maximum peak at day 98.73. The highest correlations are detected between pod accumulation rate (k) Snow pea at 25/15°C and Greenfeast at 25/15-35/25°C (R2=0.96). There were more Snow pea seeds germinated at 25/15ºC in the first 5 days while the final germination rate was not significant between combination treatments (F3,28=0.92, P=0.4421). High temperature reduced Snow pea dry shoot weight at 25/15-35/25°C compared to Greenfeast which had a low significant dry shoot weight at 25/15°C. Root dry weight of both cultivars was reduced with high temperature (25/15-35/25°C) compared to the low temperature (25/15°C). In terms of protein and sugar content, Greenfeast had the highest protein content and higher sugar content than Snow pea at 25/15°C temperature regime.
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    The effect of temperature on growth and development of peas : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Horticulture at Massey University
    (Massey University, 1983) Ragan, Paul
    The influence of temperature on the growth and development of the garden pea was studied at Massey University during 1978-79. Cultivars with single and multiple (double and triple) podding characteristics were grown in a greenhouse experiment with high, medium and low temperature treatments, a field experiment with four successive sowings and a climate room with alternating high and low temperature treatments be­tween vegetative and reproductive growth phases. Plant response to temperature was examined using growth analysis and component analysis techniques. High temperature produced a smaller plant with shortened internodes and a delay in pod set. Net assimilation rate was closely linked with final fresh weight yield and harvest index. There was a direct relation­ship of net assimilation rate and growth duration to yield when net assimilation rate was not limiting; fresh weight yield increased in direct relation to the number of yield components. High temperature effects complicated by flower and pod abortion indicated that the be­havior of yield components must be considered along with harvest index as a selection criterion for earliness and high yield in peas. In all cultivars, the number of yield components decreased as temp­erature increased, particularly the number of pods per node when high temperature occurred during the vegetative phase. High frequency podding cultivars exhibited the highest instability. Net assimilation rate and competition for assimilates between yield components (sinks) determined the number of yield components that were retained. No one component was identified as the main source of variation in pea yield. Positive inter­actions between components of yield were identified with yield increases when net assimilation rate was nonlimiting and yield decreases when net assimilation rate was limiting. Negative interactions were associated with yield stability. A balance of negative and positive interactions between components of yield combined with a nonlimiting net assimilation rate (assimilate supply) is needed in high yielding pea cultivars.
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    Some aspects of seed infection and control of the collar-rot complex of peas (Pisum sativum L.), caused by Mycosphaerella pinodes (Berk. and Blox.) Vestergr., Phoma Medicaginis var. pinodella (Jones) Boerema and Ascochyta pisi Lib. : a thesis presented in partial fulfilment of the requirements for the degree of Masterate of Agricultural Science.
    (Massey University, 1972) Hor, Yue Luan
    The green pea, Pisum sativum L., is one of the principal field crops in New Zealand (Anon, 1970a), and essentially two varieties, P. sativum var. sativum (garden peas) and P. sativum var. arvense (field peas) are grown. Peas of the garden variety are used for human consumption and may be consumed fresh, processed or marketed as split peas. The field variety is mainly used for animal consumption. However both varieties are widely grown for seed production and are important to New zealand in international seed trade. The cultivation of green peas in New Zealand has increased steadily over the last few years. In 1966-67 approximately 28,000 acres were sown, while in 1968-69 this had increased to approximately 50,000 acres (Anon, 1970a). The main pea producing areas are Canterbury, Wellington, Marlborough, Hawkes Bay and Otago, with Canterbury alone being responsible in 1967-68 for three-quarters of the total production in New Zealand (Anon, 1969). In 1968-69 export of seed peas and artificially dehydrated peas alone resulted in total earnings of more than two million dollars (Anon, 1970b). [From Introduction]
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    Quantitative inheritance studies in the garden pea (Pisum sativum L.) : a thesis ... for the degree of Master of Horticultural Science in Plant Science at Massey University
    (Massey University, 1982) Grant, Douglas
    A quantitative inheritence study of leaf form in the garden pea, Pisum sativum L., was carried out using an eight parent F¹ half diallel cross. The inheritance of yield and its components were also studied. The parental lines used for the diallel contained combinations of the following genes which act in the homozygous recessive condition = af. converts normal pea leaflets to tendrils, tl converts normal pea tendrils to leaflets and st reduces the size of the stipule. A combination of af. and tl together results in a mass of small leaflets. The characters measured included length, width, areas and weights of leaflets, stipules and tendrils and the components of yield. The data from the twenty-eight F¹ crosses and their eight parents were analysed with Hayman-Jinks diallel method. The adequacy of the additive-dominance model was determined by the relationships of Wr and Vr: the analysis of variance of (Wr - Vr), the Wr on Vr regression analysis and the WrVr graphical analysis. The results indicated the predominance of additive genetic variance for the vegetative characters although dominance variance and non-allelic interactions were important. The inheritance of yield and its components were mainly attributable to additive genetic variance while the type of dominance varied from partial to complete for both types of characters. Heritabiity was high for the vegetative characters and medium to low for the components of yield.
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    The effects of drying methods and storage conditions on pea seed (Pisum sativum L.) quality and the relationship between high temperature drying and maize seed (Zea mays L.) stress cracks : this thesis presented in fulfilment of the requirements for the degree of Master of Applied Science (Agricultural Engineering) in the Institute of Technology and Engineering, Massey University, New Zealand
    (Massey University, 1998) Thuy, Nguyen Xuan
    High temperature and high relative humidity adversely affect the quality of seeds, and are features of tropical climate. Seed drying and storage are being used increasingly in developing countries to improve seed storage and quality. This study was undertaken to evaluate a range of seed drying methods and storage conditions with the view to selecting an appropriate method(s) for use in tropical countries. Pea (Pisum sativum L.) seeds at three initial seed moisture content (m.c.) of 23.8, 18.0 and 14.5% were dried to 10% seed m.c. before storage. The performances of four different drying methods: artificial dryer (Kiwi Mini) set at 30°C or 45°C, natural sun drying, and in-bin natural ventilation drying were evaluated. Natural sun drying, and in-bin natural ventilation drying were conducted from March to May, 1997, when mean temperature and relative humidity during sunny days were 17°C and 60% respectively. The dried seeds were stored under two conditions: open storage at 20.5°0 and 55% relative humidity (r.h.), and closed storage at 25°C and 90% r.h. for 20, 40, and 60 days. Time and energy consumed for drying by the different methods were determined to compare the drying efficiency when combined with quality of the seed. Deterioration of the seed due to storage conditions and drying methods used was determined by assessing their effects on seed germination, abnormal seedlings, dead seed, hollow heart percentages, and conductivity. Seed samples dried by the Kiwi Mini dryer set at 45°C took 7 hours and those set at 30°C took 17 hours. It took 54 hours with natural in-bin ventilation drying, while sun drying took 37 hours. However, energy consumed when drying seeds at 30°C was 17 kWh, which was more than twice that at 45°C. Seed germination was not significantly different between drying methods, but averaged only 75% because of sprouting damage of the crop prior to harvest. Germinations after open and closed storage for 20 days did not differ, although some differences appeared after 40 days of storage. However, open and closed storage for 60 days significantly reduced seed germination to 54 and 33% respectively. Because seeds are heat-sensitive, drying air temperature and drying rate are particularly important to avoid internal seed breakage, cracking and splitting, fungal growth, and loss of germination and vigour. Selected studies have shown that seed can be dried at high temperature for a short time, followed by tempering to re-distribute moisture and temperature inside the seed, thus reducing the percentage of cracking. Thus, a second experiment was conducted with maize (Zea mays L) to study the impact on seed viability of high temperature drying followed by tempering. Maize at 28.5% initial seed m.c. was dried at 60°C for short periods of 5, 10, 15, 20, or 25 minutes, followed by tempering for 45 minutes at either 30°C or 21°C. This cycle was repeated until maize seeds were dried to 13.0% m.c.. The percentage of cracked seeds, germination immediately after drying, and after an accelerated ageing test, did not differ between 30°C and 21°C tempering. Drying exposure times of up to 10 minutes per cycle at 60°C caused vertical cracks in up to 50% of seeds, but seed germination remained over 90% and seed vigour was also maintained. The percentage of seeds with stress cracks due to high temperature drying (5 - 25 minute cycles) at 60°C followed by tempering had polynomial relationships with seed germination and vigour. Seeds dried at the same temperature without tempering had their germination reduced from 99 to 20%.
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    Effect of plant nutrition, time and method of harvesting on seed yield and quality of wrinkled and smooth-seeded pea (Pisum sativum L.) varieties : a thesis presented in partial fulfilment of the requirements for the degree of Master of Agricultural Science in Plant Science (Seed Technology) at Massey University
    (Massey University, 1996) Padrit, Jump
    Effects of nitrogen(N), phosphorus(P) and time and method of harvesting on seed yield and quality were examined for smooth(Maple) and wrinkled(Pania)-seeded pea cultivars. These cultivars were grown under field conditions, and at different rates of N(0, 100 and 200 kg N/ha) and P(0 and 250 kg superphosphate/ha). Seed was harvested at 3 different times(35%, 25% and 15%SMC), and shelled either by hand or by a combine-harvester(at 1,350rpm). For hand-shelling, 120 plants were sampled from each plot of which 40 plants were used to determine the number of pods/plant, seeds/pod and 1000-seed weight, and subsequently used to determine seed quality i.e. Standard Germination, Accelerated Aging, Conductivity and incidence of Hollow Heart. The remaining 80 plants from each plot were used for separation into bottom, middle and top pods and subsequently used to determine 1000-seed weight, seed germination, conductivity and the incidence of hollow heart. For machine-threshing, 120 plants were sampled from each plot, threshed by combine-harvester and seed subsequently used to determine seed quality by 1000-seed weight, Standard Germination Test, Accelerated Aging, Conductivity Test and incidence of Hollow Heart. Samples from each plot, following machine-threshing, were also used to determine seed damage by visual observation and by the Ferric Chloride Test. Pea cv. Pania produced higher seed yield than cv. Maple in both hand-shelling and machine-threshing due to a much higher numbers of seeds/pod(5.76 and 3.57 seeds/pod, respectively) and much lower mechanical damage(10.32% and 27.98%, respectively), but had a much lower capacity to produce seed of high vigour than cv. Maple. Application of nitrogen increased seed yield of both hand-shelled and machine-threshed seeds due to increased numbers of pods/plant, whereas yield was not directly affected by phosphorus addition. However, interaction between 100kg N/ha and 250 kg superphosphate/ha decreased seed weight. Application of nitrogen also increased seed vigour as expressed by increased seed germination percentage after accelerated aging, decreased hollow heart incidence and decreased conductivity value, particularly in cv.Pania. Application of phosphorus had only a small effect on seed vigour compared with that of nitrogen. Neither seed germination percentage nor mechanical damage was affected by application of nitrogen or phosphorus. Hand-shelling at different seed moisture contents did not affect seed germination percentage or conductivity value of either cultivar, but delaying the harvest(at the lower seed moisture content) decreased seed vigour in cv. Pania, as expressed by decreased seed germination percentage after accelerated ageing and increased hollow heart incidence. Machine-threshing at different seed moisture contents resulted in different degrees of seed damage, and decreased seed vigour in both cultivars. The most severe damage in cv. Maple occurred when machine-threshed at 15%SMC, whereas in cv. Pania it occurred at 35%SMC. Least damage occurred at 35% and 25%SMC in cv. Maple and cv. Pania, respectively. Unlike hand-shelling, machine-threshing at lower seed moisture content resulted in higher seed vigour in both cultivars, suggesting that bruising which occurs mainly at the high seed moisture content is more harmful than splitting which mainly occurs at the low seed moisture content threshing, in terms of decreasing seed vigour. The top pods on pea plants produced seeds with lower seed weight in both cultivars, with higher hollow heart incidence in cv. Pania and with higher conductivity value in cv. Maple, than middle and bottom pods. Application of 200 kg N/ha and 250 kg superphosphate/ha improved vigour of seed from different pod positions to a similar and high level.
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    Growth studies with peas : a thesis presented in partial fulfilment of the requirements for the degree of Master of Philosophy at Massey University
    (Massey University, 1981) Floyd, Robert Muir
    Two experiments were conducted on vining peas under field conditions and their growth was followed using growth analysis techniques. In the first experiment, cv Victory Freezer was grown to maturity and the growth parameters total plant dry mass, leaf area and leaf dry mass recorded at weekly intervals for each of four planting densities. Determination of weekly values of R,E and F where R is mean relative growth rate, E is mean net assimilation rate and F is mean leaf area ratio, was unsatisfactory due to harvest variability. By fitting loge values of each parameter over the harvest period to quadratic functions, of the form Ŷ = a + bT + cT2 where Ŷ is the derived parameter value, a, b, and c are regression constants and T is time, it was possible to calculate instantaneous values for R, E and F. Calculation of R over the whole of growth by this method was not satisfactory. A third method of deriving R, E and F was then attempted by fitting the logistic function W = A(1-e-(λ +kT)θ)1/θ where W is the required parameter, A is the asymptote, e the base of natural logarithms, λ, k and θ are constants and T time. Values of R obtained by this method appeared to more closely approximate to the growth patterns of peas. However, due to the non-asymptotic growth of leaves the method was not suited to derivation of E and F over the whole of growth. Fitting of growth parameters to the model was also difficult where appreciable variability existed in the parameter to be fitted. At the lower plant densities, Relative Growth Rate was maintained at a higher level for much of the growth period apparently due to a higher net assimilation rate. In this experiment maximum yield was shown to occur at the highest plant densities. This was despite lower numbers of pods per plant; numbers of peas per pod and individual pea fresh mass being little affected by density. The second experiment compared three near isogenic lines of cv Dark Skinned Perfection vining pea, differing only in the expression of leaf, tendril and stipule. Each was grown at the same range of densities as in the first experiment. By the time that this experiment was half grown, the weather conditions were unfavourable for growth, with strong winds, heavy rain and low light levels. These conditions were ideal for the spread of fungal disease and the combination of weather and disease made growth very erratic. Despite the poor conditions recording of growth parameters continued until no further plots were available for harvest. At that stage only a few plots had commenced fruiting and little yield data was obtained. The very variable growth parameter records made interpretation of R,E and F almost impossible. The ease of fitting the quadratic function made it seem that this was the only method worth attempting for derivation of R, E and F values over the experimental period. Results obtained showed that in contrast to the first experiment the higher density of planting conferred many benefits to the peas. Higher leaf area ratios in the more closely planted plots led to larger values of R in this experiment. Weather effects on density were mirrored in leaf reduction where the relative growth rate of the least leafy cultivar was much lower than for the more conventional types, due again to lower values of F. The difficulty in obtaining meaningful mean values of the derived functions in both experiments suggests that different methods of deriving R, E and F are desirable. Using quadratic regression to derive these functions is limited in following whole of growth changes. Fitting of the logistic model is also difficult particularly where harvest variability is high and where the parameters are not basically asymptotic in form. It is suggested that fitting of functions to data over only part of growth may be advisable.
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    Changes in inhibitor levels, stomatal aperture, and growth of Pisum sativum L. subjected to wilting stress cycles during different developmental stages : a thesis submitted in partial fulfilment of the requirements for the degree of Master of Horticultural Science at Massey University
    (Massey University, 1974) Ivey, Ian David
    Plants of Pisum Sativum L., grown under controlled environmental conditions, were subjected to wilting stress cycles at different developmental stages and analyzed for changes in inhibitor levels, stomatal aperture, water status, and effects on final yield. As leaf water potential decreased past a critical level, stomatal aperture decreased markedly and, at the same time, inhibitor levels increased rapidly. The naximum inhibitor levels attained, as determined by several different methods of assessment, approximately halved with each later wilting cycle, whilst the degree of stomatal closure was approximately the same for each cycle. During the recovery phase, plant water status recovered to normal 24 hours after rewatering. At this time inhibitor levels had decreased markedly and, in the later cycles, had apparently declined to normal levels. However stomatal aperture had only recovered slightly at this point in all cycles and by 4 days after rewatering stomata had generally regained normal apertures. Results of the final yield analysis were confounded somewhat by the shooting of basal buds, particularly on plants subjected to wilting cycles during the preflovrering and flowering stages. and a possible explanation for this lateral growth is discussed. However the pod swelling stage was more sensitive to water stress than other stages. Changes in inhibitor levels alone, did not appear to be related directly to stomatal responses or any sensitivity of particular growth stages. Some possible reasons for these observations are presented on the basis of evidence available in the literature.
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    A study of production factors affecting seed vigour in garden peas (Pisum sativum L.) and the relationships between vigour tests and seed lot field and storage performance : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy at Massey University, Palmerston North, New Zealand
    (Massey University, 1992) Castillo, Abraham G.
    Results of studies on seed vigour of 206 seed lots from six cultivars of garden peas (Pisum sativum L.), conducted at Massey University, Palmerston North, New Zealand are reported in this thesis. The relationship between vigour tests and field emergence of garden pea seed lots with varying seed quality characters was evaluated in 1988 for 82 seed lots from six cultivars under unirrigated conditions and under both irrigated and unirrigated conditions in 1989 for 23 seed lots from three cultivars (Section One). Vigour of seeds produced from various plant populations, row spacings, sowing times, methods of harvest and pod positions from field experiments in the 1988-1989 and 1989-1990 cropping seasons was recorded from 96 seed lots for two cultivars (Section Two). The performance of five seed lots of varying seed quality characters stored under eight different conditions formed the basis for a discussion of potential storage, relative storability and prediction of storage life in garden peas (Section Three). Stressful conditions, i.e. extremely dry or very wet conditions, can limit germination and field emergence in garden peas. The 1988 environment (favourable rainfall and temperature) allowed good field emergence. However, low rainfall in November 1989 (unirrigated sowings) and excessive water following rain at the 30 October and 20 December 1989 (irrigated) sowings, caused reductions in field emergence. The germination test was strongly correlated with field emergence when conditions for sowing were favourable and when low germinating seed lots were included in the analysis. However, when low germinating seed lots (less than 85%) were excluded, the relationship between germination and field emergence was low and unreliable. Differences in field emergence between seed lots were a reflection of differences in vigour which were detected by the conductivity test. The conductivity test was strongly correlated with field emergence of garden pea seed lots under all sowing conditions. Expected field emergence (EFE) did not differ from the conductivity test for cv. Small Sieve Freezer under stress conditions, but it did not predict field emergence under all sowing conditions and for all cultivars. Multiple linear regression equations derived from the results differed among cultivars and for various sowing conditions, but none resembled the EFE equation currently used commercially. Removing the hollow heart effect from the EFE increased the relationship between EFE and field emergence under favourable conditions but reduced the relationship under stress conditions. Hollow heart is therefore an important component of seed lot performance under stress sowing conditions. In order to include the effect of hollow heart in the prediction of field emergence, EFE should be used. Further, use of EFE allows the determination of the quantity of seed needed for sowing to achieve a specific population, which the conductivity test result alone cannot provide. The EFE approach should be further evaluated. Conductivity and controlled deterioration test results illustrated seed vigour differences resulting from various production practices i.e.: - seeds from a population of 200 plants m-2 and a 10 cm row width harvested at 15% seed moisture content (SMC) had lower vigour than less dense plantings. Furthermore, there was a high hollow heart incidence, especially in bottom pod seeds. At lower population densities (50 and 100 plants m-2), the top pod seeds harvested at 15% SMC had higher leachate conductivity than the bottom pod seeds. These effects on seed quality were attributed to high temperature and RH within the crop canopy. The temperature within the crop canopy was 2°C - 5°C higher than the air temperature, especially at the 200 plants m-2 population density. The relative humidity within the canopy at the 200 plants m-2 population density was 5% - 10% higher than within the canopy at the 50 and 100 plants m-2 population densities. - seeds harvested at 40% SMC were of low vigour when machinery was used in harvesting. Although the seeds had attained physiological maturity, they were prone to damage when harvested at this seed moisture content. Higher vigour seeds were produced when harvesting was done at 25% SMC than at 15% SMC, even when machinery was used. - seeds from a December sowing were higher in vigour than seeds from a November sowing, which was attributed to a more favourable environment during seed development and maturity. For the later sowing, seeds developed and matured during February / March when the temperature (2°C - 5°C lower than January) and RH (5% - 10% lower than January) were more suitable for seed development. - seed deterioration in the field was increased by windrowing because during the time seeds were in the swath prior to harvest, they were exposed to high temperature and relative humidity. Decline in germination and field emergence was faster in low vigour seed lots than high vigour seed lot in all storage conditions. Results from the conductivity and controlled deterioration tests (vigour tests) provided better data for determining potential storability in garden peas than the germination test. The conductivity and 6 day CD tests had the best relationships in most of the controlled storage conditions and were good predictors of germination and field emergence after storage. However, better prediction of storage life was obtained under controlled storage conditions than under ambient storage conditions, probably because of greater uniformity in the germination decline. Further work is required to develop a test for predicting storage life in ambient conditions. Probit analysis of the decline in germination under the eight different storage conditions produced variable results. Under controlled storage (e.g. 25°C / constant 13% SMC) which produced a high decline in germination, the germination data when transformed into probits followed a curve, rather than the expected straight probit line for all seed lots. This may be attributed to the indeterminate character of peas which causes variable seed quality parameters at harvest, and therefore the production of heterogeneous seed lots. The data suggest that the probit model is not entirely appropriate for the prediction of storage life in garden peas, and more work is required to determine the effect of heterogeneity on storage performance.