Phytotoxic effect of 2-benzoxazolinone (BOA) against some vegetable crops.

ABSTRACT

Benzoxazolin-2(3H)-one (BOA) is a well known allelochemical that is being explored for its herbicidal activity. However, not much is known about its effect on crop plants. The present study investigated the effect of BOA on germination and early growth of four vegetable crops viz. Pisum sativum L., Raphanus sativus L., Brassica oleracea L. var. botrytis and Brassica oleracea L. var. capitata. At 1000 <M, germination of P. sativum, R. sativus and B. oleracea var. botrytis was reduced by more than 50%, whereas that of B. oleracea var. capitata was completely suppressed. Further, BOA reduced the root and shoot length of the test plants by ~ 40-82% and ~55-85%, respectively. In general, the effect was more pronounced on the root (~82% in B. oleracea var. botrytis) than on the shoot growth (~73% B. oleracea var. botrytis). 2- Benzoxazolinone significantly enhanced the contents of proteins (by 6-28%) and carbohydrates (by 61- 189%) in B. oleracea var. capitata and decreased the activities of related enzymes like proteases (by 13- 36%), a-amylases (19-60%) and b-amylase (25-70%). The observed decline in the activities of hydrolytic enzymes amylases suggest that BOA interferes with the vital metabolic processes in the germinating seedlings leading to growth reduction. The study reveals that BOA interferes with the germination and early seedling growth of vegetable crops and induces biochemical alterations.