Abstract
Characteristic features of the ontogenetic cycle of Cucumis anguria grown under greenhouse conditions in gravel cultures were traced from germination to maturity. Growth and development were compared in high and low-N plants in both long and short day ( 8 and 16 hrs.). Outstanding responses showed that high N, 16-hr. plants attained a stem length higher than N, 8-hr. plants. At low N levels stem length of short day plants exceeded that of long-day plants. Plants in 8-hr. photoperiod produced more nodes and leaves but smaller leaf area and root systems than plants in 16-hr. day-length. Min. and max. periods of vegetative and reproductive organ differentiation and growth, water and salt absorption, and pH changes of nutrient solns. were established. Fresh and dry wts. of long day plants were greater in short day plants at both N levels. Chem. analysis disclosed values unique to the exptl. variables. The data suggest that in plants grown at uniform levels of nutrient supply, certain aspects of ontogeny are closely correlated with specific stages of development, and perhaps conditioned by them as inherent regulatory factors.