Boron Source and Lime Effects on the Yield of Three Crops Grown in Peat1
- M. Prasad and
- E. Byrne2
The necessity of adding B in peat soils is recognized. A limited amount of information is available regarding toxic levels of B in these soils. A greenhouse experiment was therefore carried out to measure effects of three levels of lime × four levels of B (including control) × two types of B source on tomato (Lycopersicon esculentum Mill cv. Eurocross BB), cucumber (Curcumis sativus L. cv. Sporu), and sweet corn (Zea mays L. cv. Golden Cross Bantam) in a peat soil. The two sources of B were sodium tetraborate and B-frit. The crops were grown for about 7 weeks.
“Lime had a significant effect on yield of tomato, cucumber and corn, while B-rate had a significant effect on yield of tomato and cucumber only. B-rate had a significant effect on B-concentration of all three crops — B-source had a significant effect on B-concentration of sweet corn only.”
Visible toxicity symptoms were recorded with cucumber and corn at three times the normal rate of B application. The plant levels of B at which toxicity occurred were 115 and 53 ppm for cucumber and corn, respectively. Hot water soluble B up to 10 ppm failed to produce toxicity symptoms.
Significant correlations between hot-water soluble B and B concentration in plant and B-uptake suggested that hot-water soluble B was an effective soil test for peat soils in spite of the fact that it can overestimate the availability of B at high lime levels. The critical values of hot-water soluble B for deficiency and toxicity are much higher than in mineral soils.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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