Growth, yield and nutrient uptake of guava (Psidium Guavaja L.) affected by soil matric potential, fertigation and mulching under drip irrigation

Abstract

Our objective was to examine the effect of plastic mulching, three soil matric potentials (SMP) treatments    {I1(-20 kPa), I2(-40 kPa), and I3(-60 kPa)} and three fertigation levels {F1(100%), F2(80%), and F3(60%) recommended dose of fertilizer} under drip irrigation conditions for nutrient uptake, growth parameters and yield in guava plants.  The experiments were set up in factorial randomized block design with eighteen treatment combinations.  The experiments were conducted during the year 2012-13.  The investigation indicated that the plant canopy spread in (N/S and E/W) directions was greatly affected by different treatments.  However, non-significant effects of interaction parameters were found on plant height, crop volume and plant girth.  The maximum yield was obtained in MI2F2 (68.66 kg per plant and 22.86 t ha-1) followed by NMI2F2 (66.50 kg per plant and 22.14 t ha-1) treatments.  The maximum percentage of high quality (fruit levels A and B) were 48.2% and 50.1% in -40 kPa  irrigation treatment for mulch and no mulch conditions under 100% application of recommended dose of fertilizers.  The varying range of leaf nutrients observed for different treatments of irrigation, fertigation and mulch is  1.26-1.74% N, 0.14-0.26% P, 0.44-0.88% K, 36.33-74.23 ppm Zn, 11.33-32.76 ppm Cu, 415.6- 557.3 ppm Fe, 26.80- 39.06 ppm Mn, 0.533-0.762 % Mg and 3.42-5.06% Ca.  Based on the results above, it is recommended that controlling SMP between -40 kPa to -45 kPa at 0.2 m depth immediately under the drip emitter and fertilizer dose of 80% recommended dose of fertilizer can be used as an indicator for drip irrigation scheduling in semi-arid region of northwest India.   Keywords: fertilizer application, irrigation strategies, pressure head, tensiometer, leaf uptak