OPTIMIZATION OF HARVESTING TIME AND ROW SPACING FOR THE QUALITY OIL IN JAPANESE MINT (MENTHA ARVENSIS L.) VARIETIES
The results indicated that variety PBS-1 out yielded MAS-1 and HY-77 in oil yield. The performance of varieties differed under various row spacings. PBS-1 and MAS-1 recorded highest oil yield when planted at 45–60 cm apart whereas, HY-77 produced equal yield at all the three, row spacings. The time of harvesting depends upon the temperature conditions prevailed after planting. To get highest oil yield the crop may be harvested 120–135 (lays after planting or when the crop has enjoyed about 2680 heat units. The content of menthol and menthyl acetate increased but menthone content decreased with delay in harvesting from 120 to 150 days after planting.