[No abstract available] / Land and Food Systems, Faculty of / Graduate

Greenhouse, field and laboratory experiments were conducted to ascertain some growth and metabolic responses of the Coville blueberry variety, to sawdust and peat mulches, and the leachates of these mulches. From the greenhouse experiments it would appear that in some manner the mulches in question increased the metabolic activities of the plants. The increased activity was reflected by increased growth of the mulched plants, a higher ash content and a higher total nitrogen content of the leaves. A greater concentration of free amino acids occurred in the unmulched plants than in the mulched ones. This indicates that the nitrogen metabolic activities were hastened by the mulching. / Land and Food Systems, Faculty of / Graduate

Investigation into possible causes for reported softness of B.C. Interior tomatoes revealed that processed tomatoes from the Kelowna district were firmer than processed tomatoes from the Vernon or Kamloops districts. Soil and plant material samples from the Kelowna district were relatively high in calcium and magnesium and low in potassium compared to samples from Vernon which were relatively low in calcium and magnesium and high in potassium. Samples from the Kamloops district were relatively high in calcium, magnesium and potassium. Fruit samples from the Kelowna district contained a significantly greater amount of water-soluble pectin than fruit from either Vernon or Kamloops. Soil treatments with several nutrient elements did not produce a significant effect on water-soluble pectin in tomato fruit at Kelowna, Vernon or Kamloops, but treatments containing calcium appeared to produce the most consistent effect. / Land and Food Systems, Faculty of / Graduate

Greenhouse and field experiments were conducted with maleic hydrazide and gibberellic acid on the British Sovereign variety of strawberry at the University of British Columbia. Treatment with maleic hydrazide resulted in an increase in number of leaves and crowns per plant and an increase in mother plant vigour over control plants which were allowed to runner freely. In these respects the maleic hydrazide-treated plants responded similarly to those which had had their runners removed by hand. Length of runners and number of runner plants were effectively reduced. Top-root ratio on a fresh weight basis was decreased as a result of suppression of total top growth but there was no effect on root growth. Chemical analysis of plant tops 16 days after treatment with maleic hydrazide indicated increases in the percentages of dry weight, ash, sugar, starch (fresh weight) and in the carbohydrate-nitrogen ratio; and a decrease in the percentage of total nitrogen (dry weight). No change in total dry weight of tops was recorded. Field applications of 10 ounces of maleic hydrazide (active ingredient) per acre did not give adequate results with four applications at three-week intervals. Three applications at 25 ounces per acre at three-week intervals gave excellent runner control and mother plant vigour was equal to that of plants receiving hand runner removal. Two applications at 40 ounces per acre gave very good runner control hut mother plants were not as vigorous as those receiving three applications at the 25-ounce per acre rate. No effect of gibberellic acid application was noted on numbers of leaves, crowns, runners or flowers. Increase in fresh weight of tops, no change in roots and increase in top-root ratio were recorded 16 days after treatment, while total dry weight of tops was not affected. Two months after treatment, no effects were observed on fresh weight of tops, roots or top-root ratio. Flower truss emergence and flowering were hastened but did not result in earlier maturation of fruit. The percentage of fruit-set was reduced resulting in a reduction of weight of crop. Size of berry was also reduced. Other effects of gibberellic acid were an increase in sugar content of fruit when it was applied shortly before berry maturity and increases in length of peduncle and petiole if applied when these structures were making active growth. Chemical analysis of plant tops 16 days after treatment indicated decreases in the percentage of dry matter, sugar, starch (fresh weight) and in carbohydrate-nitrogen ratio. There was no change in the percentage of ash and nitrogen (dry weight) in plant tops. / Land and Food Systems, Faculty of / Graduate

Nitrogen fertilization of grassland and forest range in British Columbia is examined as a practical means of increasing productivity. Trials were undertaken at several altitudes and responses were studied in fenced and unfenced plots over a period of two years. Four clipping times, three rates of ammonium nitrate application and two times of application were the major treatments at most sites. Information on climate and soil was also obtained and clipped forage was analyzed for nitrogen. Increases in dry matter yield and combined nitrogen levels obtained on all sites despite the marked mid-season limitation of soil moisture; responses to autumn fertilization were evident in early growth in the spring following application; responses to spring application were delayed. Response to fertilizer has continued to be marked in the second year after application. Understory vegetation of the forest range responded to fertilization at first but by the second year, it appears, overstory vegetation (trees) was responding to the detriment of understory yield. / Land and Food Systems, Faculty of / Graduate

The effects of two applications of foliar sprays made from kelp (Macrocystis intearifolia Bory) on growth of beans (Phaseolus vulgaris L.) under three moisture regimes were investigated. Date of kelp harvest had little effect on plants grown in water excess or deficit conditions, although means for kelp collected in spring tended to be higher. On soils maintained near field capacity, spray made from kelp collected in July resulted in increases in some bean yield components beyond the effects of kelp collected in spring or fall. The effect of storage of liquefied kelp at room temperature was also investigated and found to be soil moisture dependent. Leaf and root weights of plants grown in field capacity and dry soil respectively were lower for plants treated with kelp aged for 118 days compared to plants treated with kelp stored for longer or shorter durations. In wet soil conditions, the effect of sprays on plant height was reduced by storage of the liquefied kelp. Kelp extracts were fractionated by solvent partition. The butanolic fraction was shown to increase significantly many yield variables under wet soil conditions. This fraction had cytokinin-like activity in two bioassay systems, and contained substances co-eluting with isopentenyl adenine and zeatin in column, thin layer, and gas-liquid chromatography systems. Non-significant increases for some plant yield components resulting from application of unfractionated kelp paralleled these increases. A kelp fraction with undefined constituents increased some yield variables of plants grown in field capacity soil, as did a fraction with auxin and gibberellin-like activities in bioassay. The presence of inhibitors in the kelp was indicated by significantly lower pod yields under dry soil conditions, and a reduction in cytokinin-like bioassay activity when increasing amounts of kelp were assayed. The possibility that phytohormone deficits resulting from root stress are ameliorated by some components of the kelp spray is discussed. / Land and Food Systems, Faculty of / Graduate

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