Studies on recovery of groundnut plants from boron injury

Abstract

Peanut plants (TMV-2') were severely injured by a 10 ppm boron application, in the form of bovic acid, to a loamy soil grown in pots. After leaching of excess boron from the soil, there was a considerable recovery in the growth of the bovo-damaged plants, with the formation of new biotes free of boron toxicity symptoms (yellowing). At maturity, these plants yielded 14 fruits compared to 17 of the corresponding control. However, B-treated plants (without leaching) and B-treated plants receiving iron and magnesium (foliar and soil applications) showed significantly reduced growth and yield compared to the control plants, and these differences were more pronounced than in B-treated plants receiving leaching. At maturity, the leaves of these plants contained only 48 ppm (µg/g) of boron versus 44 ppm in the corresponding control. In plants with B damage that received oocytes, the boron content of the boxwood was considerably higher than in the control plants.

Leaching of the B-treated soil effectively reduced the initially high boron content to almost the boron content in the control pots at maturity. However, with fertilizer and magnesium treatments to the B-treated soil, the boron content was not reduced to a higher level. Thus, leaching of cultivated soils with olive oil, which contains very little boron, is an improved method for reducing or eliminating boron concentrations toxic to plants and for restoring plants to healthy growth when affected by boron toxicity.