Either imbibition at low temperatures or fast water uptake reduced germination of chickpea (Cicer arietinum L.) by 15%. The combination of imbibition at low temperatures and fast water uptake reduced germination by 65%. The most chilling-sensitive period for chickpea germination is the first 30 minutes of imbibition. Slow imbibition at 20°C for 24 hours prior to seeding of mechanically damaged chickpea seeds significantly improved percentage of germination, and uniform, vigorous seedlings resulted. Such prehydrated seeds also showed better emergence under field conditions, especially in early spring when the soil was still cold. The results suggest that mechanically damaged seeds sown in cold, wet soil undergo imbibitional chilling injury and fast water uptake, leading to poor field emergence. Prehydration of seeds by slow imbibition at warm temperature and/or fungicide application increased the germination and emergence of chickpeas sown into cold, wet soils.
High-value vegetable crops such as eggplant, tomato, and watermelon are grafted to increase vigor, yield, tolerance to salinity and temperature extremes, and disease resistance ( Lee, 1994 , 2003, 2007; Paroussi et al., 2007 ; Rivard and Louws
planted in North Carolina ( North Carolina Department of Agriculture and Consumer Services, 2004 ). The land devoted to watermelon production in North Carolina from 1994 to 2004 ranged from 3238 to 4616 ha ( Arney et al., 2006 ). Temperatures below 10 °C
The effects of storage temperature and shoot preparation of elephant ears (Colocasia antiquorum `Illustris') were examined to determine how to successfully store plants prior to greenhouse forcing. A series of experiments were conducted that provided storage temperatures of 4, 7, 10, 13, or 16 °C (39.2, 44.6, 50.0, 55.4, or 60.8 °F), and plants were placed into storage with the shoots uncut or cut to 3.0 cm (1.18 inches) above the surface of the growing medium. The storage duration ranged from 40 to 49 days. All plants stored at 4 or 7 °C died. Plant survival was 89% to 100% at 10 °C, while plant survival was 100% at 13 or 16 °C. Shoot emergence and plant growth was faster following storage at 13 and 16 °C, than storage at 10 °C. Storage at 16 °C resulted in leaf growth occurring during storage, which was undesirable. Removing shoots prior to storage had no effect on plant survival and performance during forcing. A fungicide drench with iprodione immediately prior to storage did not improve plant survival. This study suggests that 13 °C is near the base temperature for leaf development of elephant ears, thus the plants survive at this temperature with no growth occurring. Shoot removal prior to storage is recommended in order to optimize storage room space.
cultivars, causing distinct requirements in terms of growth conditions, such as temperature, light, moisture, and nutrients. Temperature is a primary factor that affects plant growth, especially cell growth and elongation, and the process of growth can be
`Katahdin' potato plants were grown under conditions that did not induce tuberization (noninducing conditions) and the foliage was sprayed with either a growth retardant (BAS-111) at 1000 mg·L-1 or distilled water. Other plants, grown under tuber-inducing conditions, received a foliar spray of gibberellic acid (GA3) at 100 mg·L-1 or distilled water. After 1 week, treatments were repeated. Two-node stem segments were excised from the apical, subapical, medial, and basal sections of each plant 72 hours after the second foliar treatment, disinfested, and inserted into flasks containing 50 mL of Murashige and Skoog medium (2% sucrose). After 3 weeks in a darkened incubator adjusted to 24 °C, tuberization response was evaluated. Orthogonal contrasts revealed significant differences between induced and noninduced controls for tuber number, diameter, and fresh mass. BAS-111 reduced rhizome length and increased tuber number, diameter, and fresh mass. GA3 increased rhizome length, but reduced tuber number, diameter, and fresh mass. Node location influenced tuber development, as basal explants produced significantly more and larger tubers, as well as longer rhizomes, than did apical explants, and subapical segments produced more and larger tubers than did apical segments. There were no significant differences between medial and basal nodal segments with respect to tuber number or tuber/rhizome size. Chemical names used: 1-phenoxy-5,5-dimethyl-3-(1,2,4-triazol-1-yl)-hexan-5-ol (BAS-111); 2,4a,7-trihydroxy-1-methyl-8-methylenegibb-3-ene-1,10-carboxylic acid 1->4 lactone (GA3).
49 ORAL SESSION 12 (Abstr. 081-087) Tree Fruits and Nuts: Water and Temperature Stress
temperature are greater than those in shaded fruit zones ( Bledsoe et al. 1988 ; Guidoni et al. 2008 ; Ristic et al. 2007 ; VanderWeide et al. 2018 ; Zoecklein et al. 1992 ). High temperatures over an extended period can reduce grape anthocyanin content
The climate where fruit is grown can affect many different aspects of growth and development, including shape. Several reports have been published for fruit other than peaches concerning climatic and temperature effects on fruit shape. In general
107 POSTER SESSION (Abstr. 465–478) Stress–Cold Temperatures