Effect of dose and plant growth regulator application time on agronomic traits and yield components of Lamuru maize

The climate change of dry months for growth and production of corn, demanding the use of growth regulators. Atonic are generally known to increase metabolism and plant growth regulators. However, the optimal application time and dosage according to the location of planting in maize are unknown. This study determines the dosage and optimal time of atonic spray application to increase yield components. The study was conducted in Latosol soil in the dry land of Installation for Research and Assessment of Agricultural Technology (IP2TP) Bacan South Halmahera, North Maluku, from March to July 2019. The study was arranged in a factorial randomized block design with three replications. The first factor consists of the dose of atonic spray consisting of 4 levels, namely: 0.25cc/l, 0.50cc/l, 0.75cc/l and 1.00cc/l. The second factor is the atonic spraying time which consists of 3 levels, namely: 28 days after planting (dap), 49 dap, and 77 dap. The results showed that atonic spraying with a dose of 50cc/l at 28 dap produced the highest weight per 1000 corn seeds significantly different from spraying at 49 and 77 dap at various atonic doses. Spraying carried out at age 77 dap requires a higher atonic dose of 1cc/l to produce a weight per 1000 corn and it was correlated with leaf area at 49 dap (r=0.682) and with air temperature in July (r=0.35). High humidity (87.4%) in July was negatively correlated with plant height (r=-0.41) and weight of filled corncob (r=-0.37).