Abstract:

To explore the effects of potassium dosage and the number of remaining seedlings on the indicators related to the growth and development of maize seedlings, under hydroponic condition, we took ‘Lishou No.1’ as the material, set different potassium concentration gradients (K₁:1.35mmol/L, K₂:1.85mmol/L, K₃: 2.35mmol/L, K₄: 2.85mmol/L) and the number of remaining seedling plants (D₁: 4 plants/pot, D₂: 8 plants/pot) to study the response of plant height, stem thickness, plant fresh weight, root-shoot ratio, leaf area and chlorophyll content to potassium concentration and the number of remaining seedlings. The results showed that the application of potassium fertilizer could promote the growth of maize. Under D₁ treatment, the competition among plants was small, the nutrition was sufficient, and the growth of maize was more vigorous. With the increase of potassium concentration, plant height, stem diameter, leaf area and plant total fresh weight achieved the largest and the smallest values under K₄ and K₁ treatment, respectively. Under D₂, the plant height, total green leaf area and SPAD value of maize were the largest under K₂ treatment, which were significantly larger than those under other treatments. The stem diameter, single plant biomass, total green leaf area and SPAD value increased first and then decreased, but there was no significant difference between treatment K₂, K₃ and K₄. The root-shoot ratio of D₁ and D₂ in different concentrations showed that the root-shoot ratio of D₁ under K₁ was relatively high, while that of _D2 was relatively high in medium and high concentration.

Key words: maize seedling stage, growth and development, potassium concentration, hydroponics