Nutrient Sufficiency Ranges in Mango Using Boundary-Line Approach and Compositional Nutrient Diagnosis Norms in El-Salhiya, Egypt

Nutrient sufficiency levels for haskap (Lonicera caeruleaL.) using the boundary-line approach

“…The boundary-line approach (BLA) was proposed by Walworth et al (1986) and has been adopted by many researchers such as Schnug et al (1996), Vizcayno-Soto and Cote (2004), Blanco-Macías et al (2009) Bhat and Sujatha (2013) and Ali (2018). They used the BLA to investigate nutrient sufficiency ranges for several crops.…”

“…Thirdly, a second-degree polynomial function was generated from the selected points at α = 0.10 significant level. Finally, the optimum nutrient concentrations were determined by solving the second-degree function as described by Ali (2018). The corresponding values of up to 90% of the highest growth rate was used to define the minimum and maximum nutrient sufficiency ranges.…”

“…The corresponding values of up to 90% of the highest growth rate was used to define the minimum and maximum nutrient sufficiency ranges. Prior to the BLA steps, it is important to remove outliers from the data set (Ali 2018). Thus, outlier test was carried out to detect and remove outliers from the leaf tissue nutrient concentrations data set using box and whiskers plots ( Fig.…”

“…The positive grouping of leaf N, P and K versus plant variables indicated the importance of these nutrients in haskap growth and establishment. It has been reported that P and K are needed to stimulate growth, which leads to increased plant growth and enhanced uptake of both nutrients (Havlin et al 2014;Ali 2018).…”

“…Nutrients interactions are usually measured in terms of plant growth response and changes in nutrients concentrations (Fageria 2001). Many researchers have used different agronomic parameters such as yield (Bhat and Sujatha 2013;Ali 2018), dry matter content (Blanco-Macías et al 2009), basal-area growth for trees (Vizcayno-Soto and Cote 2004;Quesnel et al 2006) and tree growth rate (René et al 2013) to diagnose and develop nutritional standards. As it is a relatively new crop, the growth response of haskap to different levels of nutrients is in itself not well documented and thus it is not known how important plant nutrition is for haskap, or which nutrients are most important.…”