Corn (<i>Zea Mays</i> L.) Plant Characteristics and Grain Yield Response to N Fertilization Programs in No-Tillage System

Abstract

Problem statement: Nitrogen application timing and Nitrogen (N) rate are two important factors to influence corn production in No-Tillage (NT) system, but N recommendations may need to be revised due to insufficient rainfall in dryland rain-fed environment. Approach: This study was to determine the effects of two N application timing (planting and split application at planting and V6 corn growth stage) and five N rates (0, 45, 90, 135 and 180 kg N ha −1 ) on corn plant characteristics and grain yield under rain-fed and low corn yield environment. Plant characteristics included the measurement of plant height, ear height, relative chlorophyll content (SPAD) and normalized Difference Vegetation Index (NDVI). Results: Plant height and ear height at R1 stage, SPAD at R1 and NDVI at V8 and R1 increased significantly with increasing N rates, while N application timing had no effect on measured canopy characteristics. Grain yield increased from 2.2-3.8 Mg ha . However, applying more than 90 kg N ha −1 did not significantly increase grain yields. The N application timing did not influence yield. Strong correlations were observed among corn plant characteristics and between plant NDVI at V8 and R1 stages and grain yields. Conclusion:These results indicate that N application timing was not important factor to affect corn plant characteristics and grain yield under rain-fed and low corn yield dryland conditions and we may not expect a significant grain yield increase with application exceeding 90 kg N ha -1 under these conditions. Plant NDVI at V8 and R1 stage could be a good indicator to predict corn grain yield.

Characterization and Enhancement of Genetic Resources for the Improvement of Nutritional and Organoleptic Quality in Solanaceae Vegetable Crops

“…To our knowledge, no other studies evaluating plant growth, yield parameters, fruit morphology and antioxidant compounds in eggplant as a response to different N fertilization doses have been reported so far. However, our results were also congruent with studies in other species (Agegnehu et al, 2016;Han et al, 2014;Liu and Wiatrak, 2011;Si et al, 2020;. In this way, N is a major component of chlorophyll, as well as proteins and nucleic acids, thus it is the main macronutrient on which plant growth and development depend.…”

Inter-relationships of cotton plant height, canopy width, ground cover and plant nitrogen status indicators

“…Freeman et al (2007) developed a 3-dimensional index based on the multiplication of NDVI and plant height to estimate corn biomass at early and later stages (R 2 = 0.66 and 0.45), yield (R 2 = 0.62 and 0.64), and N uptake (R 2 = 0.77 and 0.46). Liu and Wiatrak (2011) proposed the use of plant height, NDVI and LAI in estimating corn grain yield. Sui and Thomasson (2006) found that plant height in combination with reflectance in visible spectral bands represented the best estimator for cotton N status (R 2 = 0.50 to 0.51).…”

Crescimento de milho em níveis contrastantes de nitrogênio e sua correlação com produtividade de grãos

“…Fato que concorda com o encontrado por Almeida et al (2003) que, avaliando a correlação do crescimento inicial e a produtividade do milho em duas safras, não encontraram correlação entre as produtividade e os parâmetros de crescimento inicial estimados, em condições de suprimento nutricional adequado e, com Liu & Wiatrak (2011) que a encontraram mesmo com referência à altura de plantas e produtividade.…”