EFFECT OF MOISTURE REGIMES, SUCKERICIDE AND WEEDICIDES ON GROWTH, YIELD AND QUALITY OF RUSTICA TOBACCO ( Nicotiana rustica L.) cv. GC 2
Abstract
A field experiment was conducted under middle Gujarat agro-climatic conditionfi, at the Bidi Tobacco Research Station, G.A.U., Anand, during 1993-94 and 1994-95 with a view to study the effect of moisture regimes, suckericide and weedicides on growth, yield and quality of rustica tobacco cv. GC 2. The experiment comprised combinations of three levels of irrigation based on IW/CPE ratio (0.7, 1.1 and 1.5) and two treatments of suckencontrol (hand desuckering and pendimethalin 0.75 per cent) alongwith five treatments of weed control (local practice, fluchloralin 1.0 and 1.5 lit/ha, pendimethalin 1.0 and 1.5 lit/ha). The experiment was laid out in a split plot design with four replications, wherein irrigation and suckericide treatments were embeded in the main plots, while weed control treatments were assigned to the sub plots. The results revealed that irrigation schedule based on IW/CPE ratio of 1.1 markedly increased plant height, leaf length and leaf width. IW/CPE ratio of 1.1 gave significantly higher cured leaf yield as compared to 0.7 and 1.5 ratios. Similarly, the spangle and growth scores were also higher under the same ratio. It is also observed that with increasing levels of irrigation the fresh weight of suckers, dry weight of weeds and orobanche weight were increased. The fresh weight of suckers, dry weight of weeds and orobanche weight were significantly higher under 1.5 IW/CPE ratio as compared to 0.7 and 1.1 IW/CPE ratios. The field water use efficiency decreased with increase in IW/CPE ratio from 0.7 to 1.5. The IW/CPE ratio of 1.1 was found to be an optimum ratio from growth and yield attributes view points. It also gave highest net realization of Rs. 15291/ha and CBR of 1:2.06. Although increase in irrigation frequency significantly decreased both total-N and leaf nicotine contents, the differences were not large to cause drastic change in the leaf quality. Application of pendimethalin @ 0.75 per cent in the leaf axil significantly improved yield and yield attributing (leaf length, width and growth score) characters as well as spangle score, a quality trait over hand desuckering. The increased in cured leaf yield was to the tune of 8.36 per cent under chemical desuckering over hand desuckering. The increase in yield was achieved due to reduction in the sucker weight. The reduction in sucker weight under S2 was to the extent of 7.32 per cent over hand desuckering. The reduction trend in dry weights of weeds and orobanche was also observed under pendimethalin application. The field water use efficiency was higher under the application of pendimethalin. Application of pendimethalin also accrued higher net return (Rs. 13022/ha) than hand desuckering (Rs. 11170/ha). Suckericidal treatment significantly decreased total-N, while nicotine content was increased, indicating improvement in the leaf quality over hand desuckering. The application of weedicide was significant in almost all attributes studied during the course of investigation, wherein application of fluchloralin 9 1.5 lit/ha gave significant improvement over local practice except fresh weight of suckers, orobanche weight as well as spangle and growth scores which were not significantly influenced by different weedicide treatments. The application of fluchloralin @ 1.5 lit/ha also significantly decreased the dry weight of weeds as compared to the local practice of weed management. The higher field water use efficiency was also observed under the treatment of fluchloralin @ 1.5 lit/ha than other treatments. Application of fluchloralin @ 1.5 lit/ha fetched the highest net realization (Rs. 14965/ha) and gave maximum CBR (1:1.99). The chemical quality parameter viz., total-N and nicotine contents of leaf lamina were significantly decreased due to the application of weedicide over local practice. However, the variation was not large enough to cause drastic changes in the leaf quality. The interaction effect I x S exhibited significant effect on leaf width, wherein I2S2 treatment combination registered the highest values. Similarly, interactions I x W, I X S, S X W and I x S x W exhibited significant influence on dry weight of weeds, where I1W3, I1S2, S2W3 and I1S1W3 registered lower dry weight of weeds. From the foregoing results it is pertinent that rustica tobacco variety GC 2 gave highest cured leaf yield as well as net returns when it was irrigated at 1.1 IW/CPE ratio (10 to 11 irrigation of 50 mm depth), chemically desuckered with 0.75 per cent pendimethalin and weed managed by application of fluchloralin @ 1.5 lit/ha alongwith irrigation under middle Gujarat agroclimatic conditions.
Description
Keywords
AGRONOMY, AGRICULTURE, A STUDY