Inversion of Growth Patterns in Normal and Mineral-deficient Plants at High Temperatures

Abstract

THE fact that at high temperatures, that is, between 30° and 40° C, the growth response of many plants to mineral deficiencies is strikingly altered does not appear to have been recorded. At these temperatures plants grown in sand cultures on a fully balanced mineral nutrient solution are appreciably smaller than ones grown on solutions lacking one essential trace element such as boron, copper, manganese, molybdenum or zinc, and this effect has been observed here for six seasons. This is the reverse of what is normally observed at more moderate temperatures, where the control tends to be the largest and healthiest plant in any experiment.