Evaluation of Planting Technologies and Management in Wheat.

Genotype by seeding rate interaction can play a critical role in understanding wheat (Triticum aestivum L.) yield potential. The objective of this study was to quantify wheat yield response to seeding rates by contrasting genotypes (high- vs. low-tillering). Four studies were established at two locations for two growing seasons (2015-2016 and 2016-2017): at Ashland Bottoms (dryland and conventional till in the first year and no-till in the second year) and at Topeka (irrigated and no-tillage for both years) field research stations (KS, US). The two winter wheat varieties were planted at four different seeding rates (45, 90, 135, and 180 kg ha^-1). Measurements consisted of stand counts, canopy coverage (estimated via imagery collection via small-unmanned aerial vehicle systems - sUAVS), determination of early-season gaps in the final stand (missing plants), spacing between plants, plant growth (biomass), final yield and its components. Early season measurements did not present differences between treatments. Biomass presented an expected trend, with exception of one site year with more variability that was reflected in yields. At Ashland, in overall (across 2-yrs), single factors seeding rate and genotype significantly impacted yields. Seeding rate factor positively affected yields, ranging from 4.7 to 5.4 Mg/ha^-1, from 45 to 180 kg ha^-1. For the genotype factor, the wheat variety WB Cedar (high-tillering) presented an overall yield improvement of 310 kg ha^-1 relative to WB 4458 (low-tillering). At Topeka, the multi-year analysis resulted with final plant density increasing yields from 3.5 to 3.9 Mg ha^-1 (from 45 to 180 kg ha^-1).