scholarly journals Managing Density Stress to Close the Maize Yield Gap

2021 ◽  
Vol 12 ◽  
Author(s):  
Eric T. Winans ◽  
Tryston A. Beyrer ◽  
Frederick E. Below

Continued yield increases of maize (Zea mays L.) will require higher planting populations, and enhancement of other agronomic inputs could alleviate density-induced stress. Row spacing, plant population, P-S-Zn fertility, K-B fertility, N fertility, and foliar protection were evaluated for their individual and cumulative impacts on the productivity of maize in a maize-soybean [Glycine max (L.) Merr.] rotation. An incomplete factorial design with these agronomic factors in both 0.76 and 0.51 m row widths was implemented for 13 trials in Illinois, United States, from 2014 to 2018. The agronomic treatments were compared to two controls: enhanced and standard, comprising all the factors applied at the enhanced or standard level, respectively. The 0.51 m enhanced management control yielded 3.3 Mg ha–1 (1.8–4.6 Mg ha–1 across the environments) more grain (25%) than the 0.76 m standard management control, demonstrating the apparent yield gap between traditional farm practices and attainable yield through enhanced agronomic management. Narrow rows and the combination of P-S-Zn and K-B fertility were the factors that provided the most significant yield increases over the standard control. Increasing plant population from 79,000 to 109,000 plants ha–1 reduced the yield gap when all other inputs were applied at the enhanced level. However, increasing plant population alone did not increase yield when no other factors were enhanced. Some agronomic factors, such as narrow rows and availability of plant nutrition, become more critical with increasing plant population when density-induced stress is more significant. Changes in yield were dependent upon changes in kernel number. Kernel weight was the heaviest when all the management factors were applied at the enhanced level while only planting 79,000 plants ha–1. Conversely, kernel weight was the lightest when increasing population to 109,000 plants ha–1 while all other factors were applied at the standard level. The yield contribution of each factor was generally greater when applied in combination with all other enhanced factors than when added individually to the standard input system. Additionally, the full value of high-input agronomic management was only realized when matched with greater plant density.

1992 ◽  
Vol 72 (1) ◽  
pp. 27-33 ◽  
Author(s):  
R. T. Weiland

Recent studies have shown that pollen from a long-season maize (Zea mays L.) hybrid increased yield of a short-season hybrid by lengthening the effective grain-filling period, while the reciprocal cross did not alter this period or yield. This effect (metaxenia) was evaluated further in the studies reported here with hybrids of more diverse maturity and under both high and low N fertility. In the first year of this study (1989), sib- and cross-pollinations were made among B73Ht × Mo17 (B × 7) and two early-silking hybrids, LH59 × LH146 (L × 6) and Pioneer 3732 (3732) under N-sufficient (275 kg ha−1) and two lower N regimes (17 and 67 kg ha−1). Only a few significant effects were observed and these were noted at high N with one exception. With 3732 pollen, grain yield of B × 7 was decreased at 275 kg N ha−1, and physiological maturity occurred 3 d earlier. Yield of 3732 was increased by L × 6 pollen in comparison with B × 7 pollen. Kernel number and average kernel weight were not altered by pollen source. Pollen type did not affect yields under low N fertility, except for a reduction when B × 7 was pollinated by L × 6 at the 67-kg N ha−1 rate. In 1990, under N-sufficient fertility, B73Ht × LH156 (B × 6), a late-silking hybrid, and LH146 × LH82 (L × 2), an earlier hybrid, were sib- and cross-pollinated with B × 7 and 3732. The only significant effect observed was that L × 2 pollen increased B × 6 yield. Thus with the hybrids used, yields of early-season types were not altered by cross-pollination with long-season types. Previous results showing increased yields when 3732 was pollinated by B × 7 were not duplicated in either year, suggesting metaxenia effects are highly dependent upon environment.Key words: Metaxenia, xenia, cross-pollination, maize, yield, N levels


1974 ◽  
Vol 10 (3) ◽  
pp. 177-184 ◽  
Author(s):  
R. C. N. Laurence

SUMMARYThe effects of plant population on the yields of four commercially important Malawian groundnut cultivars have been investigated. Pod number per plant was found to be the most variable component, bearing an inverse relationship to plant density. Kernel weight and shelling percentage were low at reduced populations, and yields and kernel size declined at very high populations. The effect of plant habit upon spacing requirement is discussed and recommendations are made.


2021 ◽  
Vol 20 (2) ◽  
pp. 363-370 ◽  
Author(s):  
Guang-zhou LIU ◽  
Wan-mao LIU ◽  
Peng HOU ◽  
Bo MING ◽  
Yun-shan YANG ◽  
...  

Author(s):  
Gustavo Castilho Beruski ◽  
Luis Miguel Schiebelbein ◽  
André Belmont Pereira

The potential yield of annual crops is affected by management practices and water and energy availabilities throughout the crop season. The current work aimed to assess the effects of plant population and soil covering on yield components of maize. Field experiments were carried out during 2014-15 and 2015-16 growing seasons at areas grown with oat straw, voluntary plants and bare soil, considering five different plant populations (40,000, 60,000, 80,000, 100,000 and 120,000 plants ha-1) and three sowing dates (15 Sep., 30 Oct., 15 Dec.) for the hybrid P30F53YH in Ponta Grossa, State of Parana, Brazil. Non-impacts of soil covering or plant population on plant height at the flowering phenological stage were observed. Significant effects of soil covering on crop physiological and yield components responses throughout the 2014-15 season were detected. Influence of plant populations on yield components was evidenced, suggesting that from 80,000 plants ha-1 the P30F53YH hybrid performs a compensatory effect among assessed yield components in such a way as to not compromise productivity insofar as plant population increases up to 120,000 plants ha-1. It was noticed a positive trend of yield components and crop final yield as a function of plant density increments.


Agriculture ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 313
Author(s):  
Guoqiang Zhang ◽  
Bo Ming ◽  
Dongping Shen ◽  
Ruizhi Xie ◽  
Peng Hou ◽  
...  

Achieving optimal balance between maize yield and water use efficiency is an important challenge for irrigation maize production in arid areas. In this study, we conducted an experiment in Xinjiang China in 2016 and 2017 to quantify the response of maize yield and water use to plant density and irrigation schedules. The treatments included four irrigation levels: 360 (W1), 480 (W2), 600 (W3), and 720 mm (W4), and five plant densities: 7.5 (D1), 9.0 (D2), 10.5 (D3), 12.0 (D4), and 13.5 plants m−2 (D5). The results showed that increasing the plant density and the irrigation level could both significantly increase the leaf area index (LAI). However, LAI expansion significantly increased evapotranspiration (ETa) under irrigation. The combination of irrigation level 600 mm (W3) and plant density 12.0 plants m−2 (D4) produced the highest maize yield (21.0–21.2 t ha−1), ETa (784.1–797.8 mm), and water use efficiency (WUE) (2.64–2.70 kg m−3), with an LAI of 8.5–8.7 at the silking stage. The relationship between LAI and grain yield and evapotranspiration were quantified, and, based on this, the relationship between water use and maize productivity was analyzed. Moreover, the optimal LAI was established to determine the reasonable irrigation level and coordinate the relationship between the increase in grain yield and the decrease in water use efficiency.


Agriculture ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 480
Author(s):  
Zhichao An ◽  
Chong Wang ◽  
Xiaoqiang Jiao ◽  
Zhongliang Kong ◽  
Wei Jiang ◽  
...  

Increasing plant density is a key measure to close the maize (Zea mays L.) yield gap and ensure food security. However, there is a large plant density difference in the fields sown by agronomists and smallholders. The primary cause of this phenomenon is the lack of an effective methodology to systematically analyze the density loss. To identify the plant density loss processes from experimental plots to smallholder fields, a research methodology was developed in this study involving a farmer survey and measurements in a smallholder field. The results showed that the sowing density difference caused by farmer decision-making and plant density losses caused by mechanical and agronomic factors explained 15.5%, 5.5% and 6.8% of the plant density difference, respectively. Changing smallholder attitudes toward the value of increasing the plant density could help reduce this density loss and increase farm yields by 12.3%. Therefore, this methodology was effective for analyzing the plant density loss, and to clarify the primary causes of sowing density differences and plant density loss. Additionally, it was beneficial to identify the priorities and stakeholders who share responsibility for reducing the density loss. The methodology has wide applicability to address the sowing density differences and plant density loss in other areas to narrow crop yield gaps and ensure food security.


2016 ◽  
Vol 53 (2) ◽  
pp. 210-225 ◽  
Author(s):  
GUILHERME M. TORRES ◽  
ADRIAN KOLLER ◽  
RANDY TAYLOR ◽  
WILLIAM R. RAUN

SUMMARYSeed-oriented planting provides a manner to influence canopy structure. The purpose of this research was to improve maize light interception using seed-oriented planting to manipulate leaf azimuth across the row thereby minimizing leaf overlap. To achieve leaf azimuths oriented preferentially across the row, seeds were planted: (i) upright with caryopsis pointed down, parallel to the row (upright); and (ii) laying flat, embryo up, perpendicular to the row (flat). These treatments were compared to conventionally planted seeds with resulting random leaf azimuth distribution. Seed orientation effects were contrasted with three levels of plant population and two levels of hybrid specific canopy structures. Increased plant population resulted in greater light interception but yield tended to decrease as plant population increased. The planophile hybrid produced consistently greater yields than the erectophile hybrid. The difference between planophile and erectophile hybrids ranged from 283 to 903 kg ha−1. Overall, mean grain yield for upright and flat seed placement increased by 351 and 463 kg ha−1 compared to random seed placement. Greater cumulative intercepted photosynthetically active radiation (CIPAR) was found for oriented seeds rather than random-oriented seeds. At physiological maturity upright, flat and random-oriented seeds intercepted 555, 525 and 521 MJ m−2 of PAR, respectively. Maize yield responded positively to improved light interception and better radiation use efficiency. Under irrigated conditions, precision planting of maize increased yield by 9 to 14% compared to random-oriented seeds.


2016 ◽  
Vol 155 (5) ◽  
pp. 703-724 ◽  
Author(s):  
A. MULUNEH ◽  
L. STROOSNIJDER ◽  
S. KEESSTRA ◽  
B. BIAZIN

SUMMARYStudies on climate impacts and related adaptation strategies are becoming increasingly important to counteract the negative impacts of climate change. In Ethiopia, climate change is likely to affect crop yields negatively and therefore food security. However, quantitative evidence is lacking about the ability of farm-level adaptation options to offset the negative impacts of climate change and to improve food security. The MarkSim Global Climate Model weather generator was used to generate projected daily rainfall and temperature data originally taken from the ECHAM5 general circulation model and ensemble mean of six models under high (A2) and low (B1) emission scenarios. The FAO AquaCrop model was validated and subsequently used to predict maize yields and explore three adaptation options: supplemental irrigation (SI), increasing plant density and changing sowing date. The maximum level of maize yield was obtained when the second level of supplemental irrigation (SI2), which is the application of irrigation water when the soil water depletion reached 75% of the total available water in the root zone, is combined with 30 000 plants/ha plant density. It was also found that SI has a marginal effect in good rainfall years but using 94–111 mm of SI can avoid total crop failure in drought years. Hence, SI is a promising option to bridge dry spells and improve food security in the Rift Valley dry lands of Ethiopia. Expected longer dry spells during the shorter rainy season (Belg) in the future are likely to further reduce maize yield. This predicted lower maize production is only partly compensated by the expected increase in CO2 concentration. However, shifting the sowing period of maize from the current Belg season (mostly April or May) to the first month of the longer rainy season (Kiremt) (June) can offset the predicted yield reduction. In general, the present study showed that climate change will occur and, without adaptation, will have negative effects. Use of SI and shifting sowing dates are viable options for adapting to the changes, stabilizing or increasing yield and therefore improving food security for the future.


2021 ◽  
Vol 12 ◽  
Author(s):  
Adnan Noor Shah ◽  
Mohsin Tanveer ◽  
Asad Abbas ◽  
Mehmet Yildirim ◽  
Anis Ali Shah ◽  
...  

High plant density is considered a proficient approach to increase maize production in countries with limited agricultural land; however, this creates a high risk of stem lodging and kernel abortion by reducing the ratio of biomass to the development of the stem and ear. Stem lodging and kernel abortion are major constraints in maize yield production for high plant density cropping; therefore, it is very important to overcome stem lodging and kernel abortion in maize. In this review, we discuss various morphophysiological and genetic characteristics of maize that may reduce the risk of stem lodging and kernel abortion, with a focus on carbohydrate metabolism and partitioning in maize. These characteristics illustrate a strong relationship between stem lodging resistance and kernel abortion. Previous studies have focused on targeting lignin and cellulose accumulation to improve lodging resistance. Nonetheless, a critical analysis of the literature showed that considering sugar metabolism and examining its effects on lodging resistance and kernel abortion in maize may provide considerable results to improve maize productivity. A constructive summary of management approaches that could be used to efficiently control the effects of stem lodging and kernel abortion is also included. The preferred management choice is based on the genotype of maize; nevertheless, various genetic and physiological approaches can control stem lodging and kernel abortion. However, plant growth regulators and nutrient application can also help reduce the risk for stem lodging and kernel abortion in maize.


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