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Abstract

Flower bud initiation of herbaceous peony (Paeonia L.) may start soon after the current year’s flower anthesis in June; buds continue to develop until the onset of dormancy in the fall. Flower formation, days to harvest, foliage senescence, and dormancy are unaffected by photoperiod. Flower bud dormancy can be broken by storage of dormant plants for a minimum of 4 weeks at 5.6°C after which they may bloom in the greenhouse in 8 to 10 weeks. Increasing storage time to 6 weeks or reducing the temperature to 1° increases the total number of shoots that grow after forcing.

A renewed interest in perennial garden plants occurred during the 1980s. The need for more information on how to force the plants for flower-show exhibition prompted this research. Experiments were designed that combined the effects of cold storage, daylength, and greenhouse temperature on the development of perennials. The six species and cultivars studied were categorized by the interaction of cold and daylength on their growth and flowering strategy.

Ease of pod detachment is an important consideration when selecting cultivars for mechanical harvest at the mature-green stage. Sixteen southernpea cultivars and breeding lines were evaluated for pod detachment force. The cultivars varied in pod detachment force. MN-13 had the largest detachment force with a measurement of 2.18 kg. Royal Cream had the smallest detachment force with a measurement of 1.2 kg. Pod length, pod diameter, pod weight, basal pod fill, and length of peduncle synapse was recorded for each pod sampled for detachment force. There was no clear association between pod detachment force and the five traits.

Abstract

An instrument for determining the force required to pull the peduncle from a cucumber fruit is described. Picking force was studied using the pickling cucumber cultivars Wisconsin SMR-15, Ohio MR-17, and Wisconsin SMR-12 in 3 positions in the picking force instrument on 3 harvest dates. Picking force was more highly correlated with fruit length than fruit weight or diameter. Regression coefficients of picking force on fruit length were homogeneous for cultivars, stem positions, and harvest dates. Significant differences in mean picking forces were detected for cultivars, position of the fruit in the picking force instrument, and harvest dates. The cultivar sequence of increasing picking force was ‘Wisconsin SMR-12’, ‘Wisconsin SMR-15’, and ‘Ohio MR-17’.

Abstract

The identification of dormant buds of blackcurrant (Ribes nigrum L. cv. Wellington XXX) as floral or vegetative was attempted by forcing single buds to grow. The influence on forcing of time of year, hormone treatment, and position of buds on the shoots were investigated. Buds grew out more in February than November; gibberellic acid (GA) promoted bud growth in November, while 6-benzylamino purine (BA) at 50 ppm inhibited bud development. Buds that originated from the proximal part of the shoot grew out more than the distal ones.

Abstract

Belgian endive (Cichorium intybus L.) is an important salad vegetable in Europe (Ryder, 1979; Yamaguchi, 1983). The increasing per-capita consumption of Belgian endive in Europe and in urban areas of the United States, and its high market value (Corey and Whitney, 1987), indicates increasing potential marketing opportunities for this crop. Markets in the United States prefer firm, well-closed (tight), white chicons (blanched, edible head) that, on average, are 10 to 20 cm long and weigh 60 to 110 g (Hill, 1987; Ryder, 1979). Production of the chicons involves growing and harvesting the roots, storing the roots at –1 to 3C for vernalization, and then forcing them (Corey and Whitney, 1987), Blanched chicons are obtained by forcing vernalized roots in soil or hydroponically in the dark.