Trickle irrigation of burley and dark fire-cured tobacco
A study was conducted to determine the effectiveness of drip irrigation in the production of burley and dark fire-cured tobacco. The burley and dark fire-cured plots were treated as separate experiments; TN 90 was used as the burley variety and TN D950 was used as the dark fire-cured variety. A randomized complete block with three replications was used for each study. Plot size was four rows, with data collected only from the two middle rows of each plot. Rows were 30 m in length, with rows spaced 106 cm apart; plant spacing was 50 cm for burley and 91 cm for dark. The water source was a farm pond, filtered through a sand filtration unit. Lay flat tubing was placed between each rep, with drip tape placed the length of each row near the base of the plants. The plots were transplanted on 11 May, with irrigation withheld from all plots for approximately six weeks following transplanting. Beginning 27 June, irrigation was applied by the following treatments: 1) Check plot with no irrigation; 2) a weekly minimum of 2.5 cm of water, including incident rainfall; 3) application of 2.5 cm of water following any ten day period with no rainfall; 4) application of 0.25 cm of water on alternating days, unless incident rainfall of 0.25 cm occurred within preceding 24 hours; 5) irrigation applied as indicated by available soil moisture measured by Watermark Sensors. The irrigation treatments continued until the plots were harvested 15 August. Significant differences were observed among the irrigation treatments for both the burley and dark studies. Yields (kg/ha) for burley treatments were: 1) 2270; 2) 3355; 3) 3648; 4) 3016; and 5) 3396. Yields for the corresponding treatments in the dark fire-cured study were: 1) 2948; 2) 3416; 3) 3546; 4) 3130; and 5) 3548. Although differences were not significant, cured leaf quality as judged by a grade index was higher in irrigated plots for both studies.