EFFECT OF NITROGEN LEVELS ON PRODUCTIVITY, QUALITY AND NUTRIENT UPTAKE OF FCV TOBACCO CV. KANCHAN UNDER IRRIGATED ALFISOLS

Abstract

A field experiment was conducted with FCV tobacco cv. Kanchan during 2007-08 and 2008-09 at ICARCTRI RS, Jeelugumilli, Andhra Pradesh with four nitrogen levels viz. 100, 115, 130 and 145 kg N/ha. The results of the experiment revealed that the green leaf and cured leaf yields and green leaf/ cured leaf significantly increased with increase in N levels from 100 to 130 kg N/ha while grade index increased from 100 to 115 kg N/ha only and this was on a par with 130 and 145 kg N/ha. There was a gradual increase of nicotine and decrease of reducing sugars and reducing sugars: nicotine with increase in N levels. The Total N content and chlorophyll content index (CCI) in 10-12th leaf increased with increase in N level from 100 -145 kg N/ha and decreased as the crop growth period advances from 45–105 days after planting. The total N and K uptake (Lamina+ midrib + stem + root) with 145 kg N/ha being on a par with 130 kg N/ha was significantly higher than that with 100 and 115 kg N/ha. N and K uptake increased with increase in the crop growth from 45 days after planting to harvest. The mean per day nutrient uptake was highest between 75 and 90 days after planting. The N uptake was marginal between 90 days after planting and harvest. It was concluded that application of 115 kg N/ha, would be optimum for getting higher productivity, quality and to sustain soil fertility under irrigated northern light soil conditions (Alfisols) of Andhra Pradesh.