Effect of Humic Acid Application Methods on Yield and Some Yield Characteristics of Corn Plant (Zea mays L. indentata)

Abstract

Aims: This study was aimed to determination of humic acid application methods on yield and some yield characteristics of corn plant (Zea mays L. indentata) as grown second crop conditions. Study Design: Study was set up according to randomized complete blocks experimental design with 3 replicates. Place and Duration of Study: Research was conducted under Harran Plain conditions as second crop conditions in 2017, Sanliurfa, Turkey Methodology: Capuzi hybrid corn variety was used as a plant material. Humic Acid (HA) applications  were 0 (control), to soil (4 L da-1 HA, before sowing), to seed (%2 HA), to foliar (%0.7 HA,  when the plants have 4, 8, 12 leaves),  to soil + seed (4 L da-1 HA before sowing + %2 HA  to seeds), to soil + foliar (4 L da-1 HA to soil  before sowing, %0.7 HA, when the plants have 4, 8, 12 leaves), to seed + foliar (%2 HA to seeds + %0.7 HA  when the plants have 4, 8, 12 leaves) and to soil, seed and foliar (4 L da-1 HA to soil  before sowing + %2 HA  to seeds + %0.7 HA  when the plants have 4, 8, 12 leaves). Results: Humic acid treatments effected positively tassel flowering day, grain number per ear, grain yield, protein ratio, leaf surface temperature and chlorophyll content (SPAD) values (P≤0.05). The longest tassel flowering duration value was seen at control application whereas the shortest tassel flowering duration value was found at soil+foliar treatment. Grain number per ear value ranged from 602.8 to 655.9 numbers. The highest grain yield value obtained from seed+soil+foliar treatment of humic acid (1325.54 kg da-1) while the lowest value was seen at control parcel (1165 kg da-1). Protein ratio (%) values ranged from % 8.33-9.40. The highest protein ratio was obtained from Seed+Soil+Foliar treatment of humic acid while the lowest protein ratio value was found at control parcel. Leaf surface temperatures decreased with all humic acid applications. The highest chlorophyll content (SPAD) value was obtained from seed+ foliar treatment of humic acid whereas the lowest value was at control parcel. Conclusion: The highest grain number per ear, grain yield, protein ratio values were found in soil+seed+foliar application of humic acid. And also, the highest chlorophyll content (SPAD) values were obtained from seed+foliar treatment of humic acid. Tassel flowering duration decreased with humic acid applications. The lowest leaf surface temperature value was found at soil +foliar application. All applications of humic acid affected positively on corn plant yield characteristics.