News Update on Yield of Maize : Apr 2022

Physiological Basis of Heterosis for Grain Yield in Maize

Although heterosis in maize (Zea mays L.) has been studied since the early 1900s, very little is known about how heterosis affects the physiological components of grain yield. The objective of this study was to quantify the physiological basis of heterosis for grain yield in maize by examining maize hybrids and their parental inbred lines in terms of grain yield and its component processes, dry matter accumulation (DMA) at maturity, and the partitioning of DMA to the grain (i.e., harvest index), as well as in terms of the physiological processes underlying those two components. The genetic material consisted of 12 maize hybrids and seven parental inbred lines. Experiments were conducted from 2000 to 2002 at the Elora Research Station, ON, Canada. Data were recorded on grain yield, DMA at four stages of development, harvest index, leaf area index (LAI), final leaf number, leaf width and length, rate of leaf appearance, stay green, ear number, kernel number and weight, and number of days to silking and physiological maturity. Mean heterosis across the 3 yr was 167% for grain yield and 85 and 53% for its two component processes, DMA at maturity and harvest index, respectively. Results show that heterosis for grain yield in maize can be attributed to (i) heterosis for DMA before silking, which results mainly from greater light interception due to increased leaf size; (ii) heterosis for DMA during the grain-filling period, which results from greater light interception due to greater maximum LAI and increased stay green, and (iii) heterosis for harvest index. [1]

Analysis of growth and yield of maize, sunflower and soybean grown at Balcarce, Argentina

The objectives of this study are: (1) to analyze the capacity of maize, sunflower and soybean to produce dry matter and seed yield, including the responses to shading during flowering, and shading and thinning during seed filling; and (2) to evaluate effects of plant density and sowing date on growth and yield. This report integrates data obtained during seven years of research at Balcarce Experimental Station, Argentina. In these experiments, nutrients and water were not limiting to growth. Maize produced the most biomass because of sustained ground cover and high light conversion efficiency. It also had the largest harvest index on a dry weight basis. When dry matter was expressed in glucose equivalents, differences among harvest indices for the three crops were smaller. Flowering in maize, seed filling in soybean and flowering and seed filling in sunflower were critical periods in determination of grain yield. Sunflower had more capacity than maize to compensate for fewer grains through greater grain weight. Maize and sunflower had low stability in grain number at less than optimal plant densities. Finally, delays in sowing date significantly reduced grain yields of the three crops. These reductions were due to decreases in number of grains per m2 and in grain weight. [2]

Effect of mulch, irrigation, and soil type on water use and yield of maize

Tillage practices that maintain crop residues on the soil surface help reduce evaporation of soil water, which can benefit high water use crops such as maize (Zea mays L.). Management practices, climatic conditions, and soil type may affect how well a crop responds to surface residue. We conducted experiments with short season maize in 1994 and 1995 in Bushland, TX, USA, utilizing a rain shelter facility that has lysimeters containing monolithic cores of the Pullman (fine, mixed, thermic Torrertic Paleustolls), the Ulysses (fine-silty, mixed, mesic Aridic Haplustolls), and the Amarillo (fine-loamy, mixed, thermic Aridic Paleustalfs) soil series. In 1994, the treatments were a flat wheat (Triticum aestivum L.) straw and coconut (Cocus nucifera L.) fiber mulch of 4 Mg ha−1 with infrequent irrigations totaling 25% and 75% of long-term average rainfall for the growing season (200 mm). The 1995 treatments were similar, but used a heavier mulch of 6.7 Mg ha−1 and more frequent irrigations totaling 60% and 100% of long-term average rainfall. The mulch was applied at the 3-leaf growth stage. Mean potential grass reference evapotranspiration for the vegetative and reproductive growth stages in 1994 was 6.6 and 6.3 mm day−1, respectively, and in 1995 it was 6.8 and 7 mm day−1, respectively. The mulched and bare soil surface treatments used similar amounts of water in each year. In 1994, mulch did not affect yield, yield components, or leaf area index (LAI). No significant differences occurred in plant available water (PAW) between mulched and bare soil treatments from emergence through harvest. In 1995, mulch increased grain yield by 17%, aboveground biomass by 19%, and grain water use efficiency (WUE) by 14% compared with bare soil treatments. Mulched treatments also maintained significantly greater PAW compared with bare soil treatments until near anthesis and, after anthesis, LAI was significantly greater in the mulched treatments compared with the bare soil treatments. In 1995, mulch significantly increased grain yield and grain WUE of the maize crop in the Pullman soil, grain yield and biomass WUE of the crop in the Amarillo soil, and had no significant effect on the crop in the Ulysses soil compared with the bare soil treatments. The significant increase in water use efficiency in 1995 was the result of soil water being used for crop growth and yield rather than in evaporation of soil water. The more favorable soil water regime in 1995 compared with 1994 between the mulched and bare soil treatments was possibly due to the higher evaporative demand environment, the increase in mulch mass, and the increased irrigation frequency. This was especially important in soils where textural characteristics affected both rooting and soil water extraction by maize which limited its ability to tolerate water stress. [3]

Effect of Variety and Spacing on Growth and Yield of Maize (Zea mays L.) in Bauchi State, Nigeria

A field experiment was conducted at the Abubakar Tafawa Balewa University teaching and research farm Bauchi state of Nigeria, during the 2013 rainy season, to investigate the effect of variety and intra-row spacing on growth and yield of maize (Zea mays L.) in Bauchi state. The Treatments consist of three varieties of corn (DMR, TZEE and QPM) and three intra-rows spacing (20, 25 and 30 cm). The experiment was laid-out in a randomized complete block design, replicated three times. Data was collected on plant height, number of leaves, leaf area, leaf area index, number of cobs per plot, cob length, 100 seeds weight and grain yield. The results obtained showed that varieties differ significantly, in which, DMR significantly produced the highest yield, and followed by QPM and TZEE which are similar in yield performance. Intra-row spacing of 25 cm was observed to be significantly (p=0.05) higher than 20 cm and 30 cm spacing in all the characters studied. Based on the results of the study, it may be concluded that DMR variety and 25 cm intra-row spacing proved more promising in the study area. [4]

Growth and Yield of Maize (Zea mays L.) as Influenced by Integrated Weed Management under Temperate Conditions of North Western Himalayas

A field experiment was conducted at Experimental Station of CSIR-IIIM, Srinagar, J&K, India during kharif 2013 and 2014. The experiment was laid in a randomized block design with 4 weed management practices viz., W0=  No weeding, W1 = Hand weeding 20 and 50 days after sowing, W2 = atrazine @ 1.0 kg a.i ha-1 PRE + hand weeding 20 days after sowing and W3 = atrazine @ 1.0 kg a.i ha-1 PRE + Isoproturon @ 1.0  kg a.i ha-1 POST. The results revealed that weed management practices W2 at par with W3 significantly improved plant height, number of functional leaves, leaf area index and dry matter production at different growth stages as compared to W0, whereas W2 took significantly more number of days for the crop to reach different phenological stages over rest of the treatments including control during both years of study. Similarly, W2 being at par with W3 recorded significant improvement in all yield contributing characters over W1 and W0. Both grain and stover yields were also significantly higher with W2 over W1 and W0. Significantly higher biological yield and harvest index was recorded with W3 as compared to the rest of treatments during both the years of experimentation. [5]

Reference

[1] Tollenaar, M.A.A.L.E.A., Ahmadzadeh, A. and Lee, E.A., 2004. Physiological basis of heterosis for grain yield in maize. Crop Science, 44(6), pp.2086-2094.

[2] Andrade, F.H., 1995. Analysis of growth and yield of maize, sunflower and soybean grown at Balcarce, Argentina. Field Crops Research, 41(1), pp.1-12.

[3] Tolk, J.A., Howell, T.A. and Evett, S.R., 1999. Effect of mulch, irrigation, and soil type on water use and yield of maize. Soil and Tillage Research, 50(2), pp.137-147.

[4] Sabo, M.U., Wailare, M.A., Aliyu, M. and Sanusi, J., 2016. Effect of variety and spacing on growth and yield of maize (Zea mays L.) in Bauchi State, Nigeria. International Journal of Plant & Soil Science, pp.1-6.

[5] Rasool, S. and Khan, M., 2016. Growth and yield of maize (Zea mays L.) as influenced by integrated weed management under temperate conditions of North Western Himalayas. Journal of Experimental Agriculture International, pp.1-9.

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