Establishing of Optimum Nutrient Ranges for Canola Leaves Affected by Compost and Zinc by DRIS Analysis

DRIS method is one of the important methods that reflect the status of the nutrients within the plant tissue. Field experiment were carried out at the Research and Production Station of the National Research Centre, Nubaria region, Beheira Governorate, Egypt during 2019/2020 to evaluate leaf nutrient optimum ranges of canola affected by compost addition (0, 2, 4 and 6 ton fed-1) to the soil and foliar application of zinc (0, 50 and 100 ppm) under water regimes at 75 and 40% water holding capacity. A remarkable increase the macronutrient contents due to the addition of compost and had a positive effect, especially with the rates 4 and 6 ton fed-1 + zinc sulfate foliar spraying at a rate of 100 ppm under sufficient and deficit irrigation treatments. Under water stress, in the control treatment as compared to the treatment combination (4 ton/fed compost + 100 ppm Zn), the N index was decreased from (-143.2) to (-76.1) in this time the nitrogen a negative DRIS index indicates that the nutrient level is below the optimum. Phosphorus index was recorded (-98) reduced to (-39.4) and a negative DRIS index indicates that the phosphorus level is below optimum in these treatment combinations. Also, the DRIS index for potassium was recorded (241.2) decrease up to (115.5) and the potassium has a positive DRIS index indicates that the nutrient level is above or near to the optimum. DRIS norms could be used to test the nutritional balance of nutrients in plant and diagnose nutrient requirements through calculating DRIS indices or direct application of physiological diagnosis (PD) chart.  Objective: The objectives this study to evaluation of canola leaf nutrient optimum ranges affected by organic compost addition to the soil and micronutrient such as of zinc foliar application.