EFFECT OF PRECEDING CROP, NITROGEN AND IRRIGATION ON YIELD AND QUALITY OF FCV TOBACCO IN RAINFED VERTISOLS OF ANDHRA PRADESH

Abstract

A field experiment was conducted during 2004-07 seasons at the CTRI Research Farm, Katheru, Andhra Pradesh to improve the yield of tobacco in the tobacco based cropping systems by providing irrigation and fertilizer nitrogen to tobacco. The experiment was laid out in a split plot design replicated thrice comprising of six main plot treatments with combination of three preceding kharif crops viz., maize, soybean, fallow and two irrigation treatments viz., one and two irrigations to FCV tobacco in rabi and three sub-plot treatments viz., 30, 45 and 60 kg N/ha applied to FCV tobacco. Among the three cropping sequences maize – tobacco and fallow-tobacco being on a par and recorded significantly higher cured leaf and grade index than soybean – tobacco. Giving two irrigations significantly increased green leaf and cured leaf yields by 15.0 and 10.3% compared to one irrigation, respectively. Application of 60 and 45 kg N/ha being on a par with each other and recorded higher yields and grade outturn compared to 30 kg N/ha. Higher sugars were recorded in fallow-tobacco whereas higher nicotine and chlorides were recorded in soybean–tobacco system. Two irrigations and 45 kg N/ha recorded higher values for reducing sugars and chlorides. Nicotine content increased with increasing levels of N. Though the individual effect of irrigation and N was significant, from the non-significant effect of interaction and on leaf quality, it can be inferred that one irrigation of 25 mm with harvested rain water at 30 days is sufficient for FCV tobacco grown after maize and soybean.