Corn (Zea mays L.) is one of the most important cereal crops in many countries due to its high nutritive value and a raw material for many industrial products. This research was conducted to determine the optimum concentration of the foliar application of amino acids biostimulants at appropriate growth stage for achieving more efficient use of the foliar application on sweet corn (Zea mays saccharata) var. merkur. The foliar application used in this study was the commercial product (PerfectoseTM, liquid) which is a well known product and commonly used for different crops in Jordan. The experiment was conducted at the greenhouse during the summer of 2015. Corn plants were sprayed with four different concentrations: 1, 2, 3 and 4ml/L at three different growth stages: 7th leaf, tasseling and milk stage, while the control plants were sprayed with distilled water only. The morphological characteristics (plant height, root length and ear length), physiological characteristics (leaf relative water content and leaf water potential), and biochemical characteristics (chlorophyll content, nitrogen, phosphorus, potassium and protein content) were recorded during the experiment. The results indicated that the corn plant height, leaf water potential, chlorophyll content, nitrogen, phosphorus, potassium and protein content were significantly affected by the foliar application treatments, while the rest of the parameters studied were not significant. The treatments 4ml/L at milk stage and 1ml/L and 2ml/L at 7th leaf stage were most effective in the majority of parameters studied. It can be concluded that using foliar application of amino acids biostimulants could positively enhance sweet corn morphological, physiological and biochemical characteristics.
Exogenous Ammonium Nitrate and Urea Effects as Sources of Nitrogen on Nitrate Assimilation, Photosynthetic Pigments and Biochemical Characteristics in Zea mays L.