‘Sumter’ cucumber plants (Cucumis sativus L.) were grown in an acid-washed sand with a modified Hoagland's solution containing calcium (Ca) at 160 (control), 80, or 40 mg·liter−1. Fruits grown under low Ca levels developed water-soaked and necrotic lesions on the epidermis and pericarp of the distal end of the fruits. Some Ca-stressed fruits also developed a placental disruption near the stem-end forming a cylindrical air pocket. Fruit fresh and dry weights from 40 mg Ca/liter were lower than those of the control between weeks 4 to 7 of development. The Ca content of the fruit pericarp sections decreased with increased Ca stress. Regardless of treatment, the proximal peduncle portion contained the highest level of Ca, while the distal section contained the lowest. Seed quality was also reduced from Ca stress. Almost all dry seeds from the control but only 70% of those from 40 mg Ca/liter germinated with the standard germination test. Drying seed at 25C for 5 days reduced the viability of Ca-stressed seeds, when compared to undried seed (72% vs. 99% germination). The vigor of the control seeds was significantly higher when dried. Seeds from the 40 mg Ca/liter treatment produced a significantly higher proportion of abnormal seedlings than the control seeds (58% vs. 4%).
Research Associate, present address: Dept. of Food Science, Cook College, Rutgers–The State Univ., New Brunswick, NJ 08903.
Received for publication 8 July 1988. Salaries and research support provided by state and federal funds appropriated to the Ohio Agr. Research and Development Center, The Ohio State Univ. Journal Article no. 177-88. The cost of publishing this paper was defrayed in part by the payment of page charges. Under postal regulations, this paper therefore must be hereby marked advertisement solely to indicate this fact.