Growth and phosphorus, zinc, and manganese content of tomato, muskmelon, and honey locust at high root‐zone temperatures¹

Abstract

Horticultural species vary in growth response to root-zone temperature (RZT) that exceed 30°C, but little is known about the effects of RZT on nutrient absorption. We determined the amount of phosphorus (P), zinc (Zn), and manganese (Mn) in plants of tomato (Lycopersicon esculentum Mill. 'Jet Star'), muskmelon (Cucumis melo L. 'Gold Star'), and thornless honey locust (Gleditsia triacanthos L. var. inermis Willd.) grown in an Hoagland No. 1 nutrient solution that was held at 24°, 27°, 30°, 33°, and 36°C RZT. Tomato dry mass and P and Mn contents were highest at 27°C RZT, but tomato Zn content did not show a response to RZT. Muskmelon dry mass and P, Zn, and Mn contents, however, were highest at 36°C. Honey locust dry mass and P and Zn contents did not vary with RZT, but honey locust Mn content decreased linearly with increasing RZT. Growth and P, Zn, and Mn absorption by muskmelon were increased by continuous exposure to RZT > 30°C, whereas honey locust growth and P, Zn, and Mn acquisition were not changed by exposure to RZT > 30°C. Growth and P, Zn, and Mn absorption by tomato, however, were decreased by continuous exposure to RZT > 30°C.

INFLUENCE OF THERMAL REGIME OF SOIL ON THE SULFUR (S) AND SELENIUM (Se) CONCENTRATION IN POTATO PLANTS

“…The effect of the different mulches on root-zone temperatures were similar to those of Ham et al, [15] who reported that black polyethylene (our T4), absorbs roughly 96% of the incoming radiation while reflecting very little, thus warms the soil. Similarly to the results of Klock et al, [17] with tomato plants, the increase in total biomass was obtained in plants within the root-zone temperature ranging of 23-27 C in roots, tubers and leaflets, while outside this range (T0, T1 and T4), the dry weight fell with a lower dryweight accumulation (Table 1). Table 1 also presents the results of the biomass (in a dry-weight basis) for the different organs of the potato plants.…”

Effect of Root Zone Temperature on Accumulation of Molybdenum and Nitrogen Metabolism in Potato Plants

“…Roots (mg g À1 fw) Leaves (mg g À1 fw) [31] studying tomato plants, reported an increase in total biomass in plants within the RZT range of 24-27 C, while outside this range the dry weight fell. Engels and Marschner [5] found that corn plants grown at low root temperatures not only showed slower root growth, but also had less shoot growth, as occurred in our experiment.…”

Review: Characterization and Impact of Supraoptimal Root-zone Temperatures in Container-grown Plants

“…The higher RZT also decreased shoot growth, and therefore, the demand for P, along with decreased root respiration, likely contributed to the decreased P shoot concentration. Manganese (Mn) content in honey locust decreased with increasing RZT from 24 to 36°C but growth, P, Zn, and Mn contents were not changed by continuous exposure in a hydroponic system (Klock et al, 1996).…”