TY - JOUR
AU - SELMAN, I., W.
AB - Abstract The effects of foliar sprays of gibberellic acid (GA) on the growth of tomato plants cv. Potentate were studied in growth rooms and a glasshouse. Four sprays of GA (5 ppm) increased leaf area and whole plant weight relative to water controls grown at constant temperatures (7, 17, 22, and 27 °C) for 12 days, the largest plants being obtained with 5 ppm. Experiments made at four photoperiods (5, 10, 15, and 20 h) and at two light intensities (7000 and 10 750 lx) showed that GA increased leaf and whole plant weight at 15 h, leaf area at 10 and 15 h and stem height at all photoperiods; area, height, and weight increases were obtained at both light intensities, leaf growth being increased more by GA at 7000 lx and stem growth more at 10 750 lx. Four foliar sprays of GA (5 ppm) were combined with N supplements applied via leaf and/or root to plants in sand culture. With low supply to the roots (20 ppm N) GA failed to increase growth, but increased it at higher levels. Total N in leaf and stem was increased by GA or by NH4NO3 (10 sprays 280 ppm N) at all levels of N supplied to roots, but when applied together the effect on total leaf N was more than additive except at the highest level (540 ppm) GA increased the concentration of N (as per cent dry matter) in leaf and stem at all levels of N supplied to roots. GA and NH4NO3 together resulted in a greater amount and a higher concentration of N in the shoots (and usually also in roots) than did NH4NO3 alone. Leaf thickness (as fresh weight/unit area) could only be increased appreciably by spraying with a complete nutrient solution which reduced leaf area but not dry weight. Growth increases induced by GA were detectable 43 days after the first of four sprays in the glasshouse and after 30 days in the growth room. The persistence of GA effects was compared with those induced by sprays of NH4NO3. This content is only available as a PDF. Author notes 1Present address: Assam Agricultural University, Jorhat 4, Assam, India. © Oxford University Press
TI - Growth and Nitrogen Accumulation in Young Tomato Plants Treated with Gibberellic Acid
JO - Journal of Experimental Botany
DO - 10.1093/jxb/20.2.288
DA - 1969-05-01
UR - https://www.deepdyve.com/lp/oxford-university-press/growth-and-nitrogen-accumulation-in-young-tomato-plants-treated-with-CzcdI0bc0e
SP - 288
EP - 301
VL - 20
IS - 2
DP - DeepDyve
ER -