Yield, quality and economics of FCV tobacco (Nicotiana tabacum) in relation to preceding crops and nitrogen fertilization in Vertisols

Abstract

A field experiment was conducted during 2001-02 and 2002-03 at Rajahmundry in Andhra Pradesh with six treatments during rainy (kharif) season, viz. blackgram [Vigna mungo (L) Hepper], rice (Oryza saliva L.), soybean [Glycine max (L) Merr.], maize (Zea mays L.), green-leaf manuring with pillipesara [Vigna trilobata (L.) Verde.] and fallow; and three N levels of 30, 45 and 60 kg N/ha, applied to FCV tobacco in winter (rabi) season. Short-duration maize and rice could successfully be grown before rabi tobacco, taking advantage of south-west monsoon rains. Among the cropping systems, green-leaf manuring-tobacco recorded significantly higher cured leaf (1.92 t/ha), bright leaf (0.88 t/ha) and grade index (1.39) of tobacco followed by fallow - tobacco, whereas lowest values of these yields were recorded in soybean-tobacco. Application of 60 kg N/ha offered significantly higher cured-leaf yield and grade index, and was comparable with that of 45 kg N/ha in respect of bright-leaf yield. Interaction effects of cropping systems and N levels revealed that FCV tobacco preceded by maize, blackgram, rice and soybean responded up to 45 kg N/ha, whereas tobacco preceded by green leaf manuring and fallow responded up to 60 kg N/ha in the production of bright leaf. Maize - tobacco system recorded higher tobacco leaf-equivalent yield (2.25 t/ha). The chemical quality parameters of leaf like reducing sugars, nicotine and chlorides were within the acceptable range. Maize - tobacco and green leaf manuring - tobacco systems recorded higher net returns, whereas benefit: cost ratio was higher with green leaf manuring-tobacco and fallow-tobacco. Minimum broomrape (Orobanche cernua Loefl] infestation of 1.75% was recorded in FCV tobacco succeeding maize. It was concluded that maize - tobacoo accrued higher monetary returns, followed by green leaf manuring-tobacco system compared with fallow - tobacco.