Role of irrigation and mulch on yield, evapotranspiration rate and water use pattern of tomato (Lycopersicon esculentum L.)

Abstract

▶ Two irrigations under CPE 50 resulted 9 Mg ha −1 yield increment compare to rainfed condition. The same was 12 Mg ha −1 more under five irrigations treatment. Thus, additional three irrigations amounting 90 mm enhanced the yield by only 3 Mg ha −1 . Therefore under limited water, irrigation application with moderate (CPE 50 ) level is highly desirable instead of high frequency (CPE 25 ) irrigation. Under such cases the additional three irrigations can be employed to bring out more (1.5 times) land under irrigation with 52 Mg ha −1 more yield. ▶ Among different mulches, RSM and WPM significantly increase yield to the tune of around 7 Mg ha −1 compare to NM condition. On the other hand black polythene mulch has the capacity to increase fruit yield by 16 Mg ha −1 in expense of less water compare to NM condition. So BPM could be a good management option for tomato cultivation in the Lower Gangetic Plain of eastern India. ▶ There was a close interaction between irrigation frequency and actual evapotranspiration rate (ET R ). Thus, interval between two consecutive irrigations greatly influenced the ET R value. Increase in irrigation frequency promoted more unproductive loss of water by surface evaporation. The same was decreased with the decrease in frequency of irrigation. Maximum ET rate occur under bare soil condition, which minimized by different mulches in the order of RSM > BPM > WPM. ▶ The highest WUE value (21.6 kg m −3 ) was noted when two irrigations was applied (CPE 50 ) and the same was at the lowest point when five irrigations were supplied to the crop. Among different mulches the values were in the order of BPM > RSM > WPM > NM. ▶ Finally it can be concluded that, under water scarce situation adoption of deficit irrigation clubbed with black polyethylene mulch can be a good option for utilizing water resource most efficiently without significant decrease in yield. Irrigation management strategy invites the quantification of crop response to irrigation frequencies. Conventionally, mulches increase the yield and water use efficiency (WUE) to a great extent by augmenting the water status in the root zone profile. A field study was carried out during the winter season (November–March) of 2003–2004 and 2004–2005 at the Central Research Farm of Bidhan Chandra Krishi Viswavidyalaya (Latitude 22°58′N, Longitude 88°31′E and altitude 9.75 m amsl), Gayeshpur, India, to evaluate the effect of irrigation frequencies and mulches on evapotranspiration rate from tomato crop field as well as leaf area index (LAI), fruit yield and WUE of the crop. The experiment was laid out in a split-plot design where three irrigation treatments {rainfed (RF); CPE 50 and CPE 25 where irrigation was given at 50 and 25 mm of cumulative pan evaporation (CPE)} were kept in the main plots and the subplots contained four mulch managements {no mulch (NM), rice straw mulch (RSM), white polyethylene mulch (WPM) and black polyethylene mulch (BPM)}. Under CPE 25 , tomato crop recorded significantly higher leaf area index (LAI) over CPE 50 and rainfed condition. LAI value under BPM was 9–30% more over other mulches. Maximum variation of LAI among different treatments was recorded at 60 days after transplanting (DAT). Fruit yield under CPE 25 was 39.4 Mg ha −1 ; a reduction of 7 and 30% has been obtained under CPE 50 and RF condition. The use of mulch increased 23–57% yield in comparison to NM condition. Actual evapotranspiration rate (ET R ) was 1.82 mm day −1 under CPE 25 and declined by 15 and 31% under CPE 50 and RF condition, respectively. The variation of ET R among different mulches became more prominent under maximum water stressed (RF) condition, whereas the variation was negligible under CPE 25 frequency. Irrespective of mulching WUE was highest under moderately wet (CPE 50 ) soil environment. Among different mulches, BPM was responsible for attaining the highest WUE value (25.1 kg m −3 ), which declined by 22, 21 and 39% under WPM, RSM and NM, respectively.