Contribution of tillers to maize yield stability at low plant density

Abstract

One of the main challenges of using low plant densities in restrictive and variable environments is to maximize the use of resources in better‐than‐expected years. In this context, tillering could be an alternative to increase reproductive and vegetative plasticity. The objectives of this study were to (a) characterize the correlation between environmental conditions, tiller traits, crop grain yield, and grain yield advantages due to tillers; (b) determine the grain yield response to tillering (i.e., grain yield difference between tillered and nontillered crops) for a wide range of environments; and (c) to evaluate the effect of tiller presence on grain yield of the main shoot, considering its effect on the apical and subapical ears. Tillered and nontillered crops were evaluated under rainfed conditions during two seasons (2018–2019 and 2019–2020). These experiments were carried out at 11 sites in the southern Argentinean Pampas, varying sowing date (22 Oct. to 5 Dec.), plant density (2–3 plants m−2), genotype (AX7784 and AX7761), and soil depth. Grain yield (3.2–11.9 Mg ha−1) was correlated with tillers productivity, mainly explained by postflowering precipitations. The contribution of tillers to grain yield was more proportional than their consequent yield depression at the main shoot. Tillers either increased (3 sites) or maintained (8 sites) grain yield, and their contribution increased as the environment improved without any detrimental effect in the most restrictive environments. Tillering has the potential for increasing resource (radiation, water, nitrogen) use efficiency under low plant density strategies adopted for restrictive environments.

Yield improvement and yield components: A comparison of corn and soybean

“…There are hybrids that have a tendency to produce more than one ear plant −1 (Tokatlidis & Koutroubas, 2004), but hybrids grown at commercial populations usually produce only one ear (Duvick et al., 2004; Echarte et al., 2000; Motto & Moll, 1983; Tollenaar et al., 1992). Some hybrids produce ear‐bearing tillers at low populations (Massigoge et al., 2022; Rotili et al., 2021; Veenstra et al., 2021) which essentially increases ears plant −1 , but again tillers are usually absent at commercial populations. Producers in the pre‐mechanized era favored single‐ear hybrids (Collins et al., 1965; Crow, 1998) and this preference apparently carried over into the modern era.…”

“…Flexibility (prolificacy and/or tillering) would de‐couple yield increases from population, making it possible to end the population treadmill. The opportunity to plant at lower populations while retaining the ability to respond to higher‐yielding environments (Massigoge et al., 2022; Rotili et al., 2021; Veenstra et al., 2021) represents another advantage of flexible corn plants.…”

Corn yield components can be stabilized via tillering in sub-optimal plant densities

“…While continued study is necessary, corn tillers may provide breeders and growers with plasticity trait options to achieve desirable plant density independence in certain environments (Mylonas et al, 2020). By offering additional crop reproductive plasticity when plant-available resources surpass thresholds of selected plant densities, tillers can mitigate management deficits which cannot be remediated mid-season (Rotili et al, 2021;Massigoge et al, 2022). Future work should evaluate tiller development prediction, specifically driving factors of contrasting levels of expression plasticity, in addition to parameters influencing tiller ear development and resulting reproductive efficiency.…”

“…While previous field studies have considered corn yield as a response to tiller presence (Sangoi et al, 2009;Frank et al, 2013;Massigoge et al, 2022), efforts to understand the mechanisms and flexibility of observed compensatory relationships are lacking, at least in the US. Considering trends in corn genetic selection and agronomic management in the US, plant density is a historic focal point (Duvick et al, 2004) with highly determinate, hierarchical yield components.…”

Predicting corn tiller development in restrictive environments can be achieved to enhance defensive management decision tools for producers

“…While past work has quantified the impact of tillers on corn yield (Sangoi et al, 2009;Veenstra et al, 2021;Massigoge et al, 2022), plastic capacity (Rotili et al, 2021a;Rotili et al, 2022), and resource use (Thapa et al, 2018;Rotili et al, 2022), no substantial effort has been made to quantify the predictability of corn tiller presence in field scenarios. Corn yields were not reduced, but did respond to varying levels of tiller density (i.e., tillers ha -1 ) in previous work from the available database (Veenstra et al, 2021;Veenstra et al, 2023a).…”