Varietal Differences in Development of Maize ( Zea mays L.) Seedlings on Compacted Soils

Kovačević

Acta Agronomica Hungarica

et al. 2010

Drought and soil acidity are two major abiotic stress factors limiting maize production worldwide, generating imbalances in the manganese (Mn) and zinc (Zn) status in plants. This study was conducted to determine the effects of drought stress on the Mn and Zn status in maize genotypes grown on acid and non-acid soils and how the Mn and Zn status affects the changes in grain yield caused by drought stress and soil acidity. Seventeen genotypes were grown at two locations differing in soil acidity in Eastern Croatia in 2003 and 2004. Positive values of an aridity index indicated drought stress in 2003. The genotypes had much higher Mn and Zn concentrations on acid soil than on nonacid soil: more than twice as high in both seasons for Zn and about 6 and 9 times higher in normal and in dry seasons, respectively, for Mn. This demonstrates that drought combined with soil acidity led to the excessive accumulation of Mn in maize plants. However, variation was observed between the maize genotypes for the Mn accumulation on soils differing in acidity when drought occurred. Some genotypes accumulated Mn on acid soil irrespective of drought. The Mn and Zn status had no discernible effect on the changes in grain yield caused by drought stress and/or soil acidity.

Section: Discussionmentioning

confidence: 99%

Manganese and zinc concentrations in maize genotypes grown on soils differing in acidity

Kovačević

Acta Agronomica Hungarica

et al. 2010

“…The seedling stage may be particularly vulnerable to compaction, with increased soil strength delaying both germination and penetration of the soil surface by the radicle (Court 1985; Smith et al . 2001; Soyelu et al . 2001).…”

Section: Introductionmentioning

confidence: 99%

Consequences of soil compaction for seedling establishment: Implications for natural regeneration and restoration

Bassett¹,

Simcock²,

Mitchell³

2005

Austral Ecology

115

Soil compaction can affect seedling root development by decreasing oxygen availability and increasing soil strength. However, little quantitative information is available on the compaction tolerances of non-crop native species. We investigated the effects of soil compaction on establishment and development of two New Zealand native species commonly used in restoration programmes; Cordyline australis (Agavaceae) (cabbage tree) a fleshy rooted species, and Leptospermum scoparium (Myrtaceae) (manuka) a very finely rooted species. Seedlings were grown in a range of soil compaction levels in growth cabinet experiments. Low levels of soil compaction (0.6 MPa) reduced both the number and speed of C. australis seedlings penetrating the soil surface. In contrast, L. scoparium seedlings showed improved establishment at an intermediate compaction level. Root and shoot growth of both species decreased with increasing soil strength, with L. scoparium seedlings tolerating higher soil strengths than did C. australis. Despite these results, soil strength accounted for only a small amount of variation in root length (R 2 < 0.25), due to greater variability in growth at low soil strengths. Soil strengths of 0.6 MPa are likely to pose a barrier to C. australis regeneration. This is consistent with adaptation to organic and/or soft, waterlogged soils. Active intervention may be necessary to establish C. australis from seed on many sites previously in farmland.

“…The high proportions of the total sum of squares for vigor traits that were accounted for by state are a clear evidence of the possibility of producing high quality seeds in all the states because unlike viability, vigor traits are more influenced by seed-production environment (Dornbos 1995. Strictly speaking, variability in germination parameters appears to be highly dependent on genotype (Soyelu et al 2001) and less responsive to other factors because it is usually carried out under ideal conditions. This has been a consistent observation in all our previous studies aimed at partitioning variations in maize seed germination and seedling vigor (Ajayi and Fakorede 2000, 2007.…”

Section: Resultsmentioning

confidence: 99%

Physiological Quality of Informal-Sector Maize Seeds in Nigeria

Odeyemi

Ajayi

Olakojo

2010

Journal of New Seeds

Self Cite

Lack of access to high quality seeds is a major factor contributing to the worsening of food security situation in Africa and the integration of the formal and informal seed sectors has been advocated as the most viable option for boosting seed security. However, there are concerns about the quality of seeds from the informal sector for which information is not available. To bridge this gap, maize (Zea mays L.) seed samples were drawn from community seed producers in five states in southwest Nigeria. Seed moisture content was estimated gravimetrically and the samples were subjected to seed quality tests, namely standard germination, accelerated aging, and conductivity tests. Across states, locations within states and producers, overall mean standard germination percentage was 91.45 ± 1.51%, standard germination index 5.63 ± 0.16 d, accelerated aging germination 47.10 ± 6.15%, accelerated germination index 9.59 ± 0.77 d and conductivity 8.48 ± 0.68 µS cm −1 g −1 . These results indicate a physiologically-nonuniform seedlot with high viability but low vigor. State-to-state as well as farmerto-farmer variability in the viability and vigor of the seeds were also significant (p < 0.05), suggesting limited knowledge of the community seed producers on production and handling of high quality maize seeds. It was concluded that the production of high quality maize seed could be achieved in wetter agro-ecologies and by community seed producers. However, this will require capacity enhancement of the community seed producers and managers in 191 areas like management and harvesting of seed crop, management of postharvest operations, and detailed record-keeping.