scholarly journals Crop Cycle and Tillage Role in the Outbreak of Late Wilt Disease of Maize Caused by Magnaporthiopsis maydis

2021 ◽  
Vol 7 (9) ◽  
pp. 706
Author(s):  
Ofir Degani ◽  
Asaf Gordani ◽  
Paz Becher ◽  
Shlomit Dor

The destructive maize late wilt disease (LWD) has heavy economic implications in highly infected areas such as Israel, Egypt, and Spain. The disease outbreaks occur near the harvest, leading to total yield loss in severe cases. Crop rotation has long been known as an effective means to reduce plant diseases. Indeed, agricultural soil conservation practices that can promote beneficial soil and root fungi have become increasingly important. Such methods may have a bioprotective effect against Magnaporthiopsis maydis, the LWD causal agent. In this two-year study, we tested the role of crop rotation of maize with either wheat or clover and the influence of minimum tillage in restricting LWD. In the first experiment, wheat and clover were grown in pots with LWD infected soil in a greenhouse over a full winter growth period. These cultivations were harvested in the spring, and each pot’s group was split into two subgroups that underwent different land processing practices. The pots were sown with LWD-sensitive maize cultivar and tested over a whole growth period against control soils without crop rotation or soil with commercial mycorrhizal preparation. The maize crop rotation with wheat without tillage achieved prominent higher growth indices than the control and the clover crop cycle. Statistically significant improvement was measured in the non-tillage wheat soil pots in sprout height 22 days after sowing, in the healthy plants at the season’s end (day 77), and in shoot and cob wet weight (compared to the control). This growth promotion was accompanied by a 5.8-fold decrease in pathogen DNA in the plant stems. The tillage in the wheat-maize growth sequence resulted in similar results with improved shoot wet-weight throughout the season. In contrast, when maize was grown after clover, the tillage reduced this parameter. The addition of commercial mycorrhizal preparation to the soil resulted in higher growth measures than the control but was less efficient than the wheat crop cycle. These results were supported by a subsequent similar experiment that relied on soil taken from commercial wheat or clover fields. Here too, the wheat-maize growth cycle (without permanent effect for the tillage) achieved the best results and improved the plants’ growth parameters and immunity against LWD and lowered pathogen levels. In conclusion, the results of this study suggest that wheat and perhaps other crops yet to be inspected, together with the adjusted tillage system, may provide plants with better defense against the LWD pathogen.

Fertility reproduction features of southern carbonate chernozems in the conditions of the dry-steppe zone of Northern Kazakhstan (Shortandinsky district of Akmola region) are studied. We studied the changes of humus content in the model micro plot experience. Various variants of the experiment with non-fallow and dump steam without fertilizers, grain crops with different doses of mineral fertilizers, manure, as well as with straw and sideral crops (pea-oat mixture, Donnik) are laid down. The introduction of rotted manure in small doses of 20 t / ha did not provide an increase in humus during crop rotation. When adding 40 and 80 t / ha of manure to the fallow field, it allowed to increase the humus content by 0.24 and 0.18 % of the initial amount. The introduction of sideral steam and perennial grasses into crop rotation enhanced the processes of humification and provided a positive balance of humus. In this version of the experiment, the amount of humus increased by 0.10-0.13 %. The greatest accumulation of organic matter occurred when using melilot: the increase in humus was 0.39 %. Long-term cultivation of permanent wheat crop in one field, even with high doses of mineral fertilizers, does not provide significant reproduction of soil fertility. The application of mineral fertilizers does not contribute to the increase of humus in the soil. The greatest decrease in humus content in southern chernozems is observed in the permanent dump and waste-free pair-0.11 and 0.13% over a 6-year period of observations.


Agronomy ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1862
Author(s):  
Libing Song ◽  
Jiming Jin

In this study, the crop environment resource synthesis maize (CERES-Maize) model was used to explore the effects of declining sunshine hours (SSH), decreasing daily maximum temperature (Tmax), and cultivar replacements on growth processes and yields of maize in Northern China, a principal region of maize production. SSH were found to decrease at 189 of 246 meteorological stations in the northern provinces of China over the period of 1994–2012, and a decrease in Tmax was also seen at many of these stations. The most significant decrease in these two climate variables occurred during June to September, a period for summer maize growth. For this study, seven crop field stations in the ShaanXi province, in the Guanzhong Plain, were selected, all of which showed a downward trend in SSH and Tmax over the period of 1994–2012. The CERES-Maize model was first calibrated and validated against yield observations for these stations over the same period, and the yield simulations matched very well with observations. The model was then driven by the detrended SSH and Tmax data, and the simulations were compared with those with a trend in these two input variables. The decline in SSH was found to reduce the maize yield by 8% on average over these stations due mostly to limited root growth, and the decline for shorter SSH reduced the yield more than that for longer SSH. Meanwhile, the decrease in higher Tmax increased the yield by extending the growth period, while the decrease in lower Tmax reduced the yield by lowering the thermal time. In addition, the observed yield showed a significant upward trend, and our modeling results indicate that this increase can be attributed mainly to the frequent cultivar replacements over our study period. The replaced cultivars usually had a longer growth period than the prior ones, which compensated for the yield loss due to fewer SSH. Net maize production decreased with the combined effects of the declines in SSH and Tmax on yields. This study quantifies the contribution of changes in climate and cultivars to maize growth processes and yields and provides strong insights into maize production under a complex dynamic climate system.


2020 ◽  
Vol 36 (1) ◽  
pp. 1-9
Author(s):  
Alan J Schlegel ◽  
Yared Assefa ◽  
Daniel O’Brien

Abstract. Selection of optimal crops and cropping systems for most efficient water use specific for local environments can improve global water security. Limited irrigation with ground water is one alternative to alleviate crops from low amount or unevenly distributed water in the growing seasons in semi-arid regions. The main objectives of this research were to quantify yield-water use relationships of three limited irrigated crops, determine effect of crop selection on profitability with limited irrigation, and identify profitable and alternative crop production systems. A field study was conducted at the Kansas State University Southwest Research-Extension Center near Tribune, Kansas, from 2012 through 2017. There were four treatments in the study, two 1-yr systems of continuous corn ( L.) (C-C) and continuous grain sorghum (L.) (GS-GS) and two 2-yr rotations of corn-grain sorghum (C-GS) and corn-winter wheat ( L.) (C-W). Overall corn yield after wheat (C-W) was about 1.4 Mg (ha)-1 greater than C-C. Corn and sorghum yields were similar grown as monoculture or in rotation with each other. Available soil water at corn planting and during the growing season were 20 to 40 mm (240 cm profile-1) less in the C-GS rotation compared with C-C and C-W rotations. Corn yield increased as water use (yield-water use) increased in C-W rotation but yield-water use relationships tended to be negative in C-C and C-GS rotations. Grain sorghum yield increased with water use in both rotations but at a greater rate in GS-GS compared with C-GS. Despite greater corn grain yield in C-W, our economic analysis showed that wheat was the least profitable of the three crops causing the C-W rotation to be least profitable. In this study, the most profitable limited irrigation crop rotation was corn-grain sorghum (C-GS). Keywords: Corn-sorghum-wheat, Crop rotation, Limited irrigation, Profitability, Supplementary irrigation, Sustainability.


1999 ◽  
Vol 79 (3) ◽  
pp. 439-446 ◽  
Author(s):  
H. Li ◽  
L. É. Parent ◽  
C. Tremblay ◽  
A. Karam

Meadow soils could supply significant amounts of N for several years and reduce N requirements for the potato (Solanum tuberosum L.). We examined a combination of three crop sequences, three cultivars and six N rates in relation to tuber yield and quality. Superior, Kennebec and Snowden were grown as follows on a Tilly silty loam between 1993 and 1995: (1) 3-yr continuous potato cropping of Superior, (2) 3-yr continuous potato cropping starting with Snowden and followed by 2 yr of Kennebec, and (3) 3-yr sequence of Kennebec, oat (Avena sativa L. 'Marion') and Superior. There were six N treatments (0, 70, 105, 140, 175 and 210 kg N ha−1) and a split application of 140 kg N ha−1 (half at seeding and half before hilling). The seasons were either favorable to growth (1993), relatively wet (1994) or relatively dry (1995). In 1993 and 1994, total yield varied between 37 and 50 t ha−1. In 1995, continuous cropping of Kennebec and Superior produced 28 t ha−1 compared with 37 t ha−1 under crop rotation. The rotation increased total yield of Superior by 34% and graded yield by 42% in 1995. The N requirement was closely related to yield, rather than cultivar. Compared with continuous cropping of Superior, tuber-quality index was highest with the rotation for rhizoctonia (Rhizoctonia solani) (67 vs. 57) and common scab (Streptomyces scabies) (90 vs. 82). The incidence of both diseases decreased when at least 70 kg N ha−1 was applied. For common scab, skin coverages was higher at rates of 0, 175 and 210 kg N ha−1 than at intermediate rates of 70–140 kg N ha−1. Mineral N accumulated in the 0–60-cm layer in the interrow and increased rapidly when N rates exceeded 105 kg N ha−1. After sod breakup an N rate in the range of 70–100 kg N ha−1 and crop rotation with cereals sustained the productivity of the potato during 3 yr while minimizing the environmental impact of mineral N. Key words: Crop rotation, common scab, rhizoctonia, reduced N rates, Solanum tuberosum L.


2020 ◽  
Vol 20 (11) ◽  
pp. 3921-3930
Author(s):  
Xiaoli Xu ◽  
Xiali Mao ◽  
Lukas Van Zwieten ◽  
Nabeel Khan Niazi ◽  
Kouping Lu ◽  
...  

2012 ◽  
Vol 10 (1) ◽  
pp. 535-540 ◽  
Author(s):  
Chunqiao Mi ◽  
Dehai Zhu ◽  
Bernard A. Engel ◽  
Shaoming Li ◽  
Xiaodong Zhang ◽  
...  

2015 ◽  
Vol 737 ◽  
pp. 771-775
Author(s):  
Chang Hu ◽  
Dang Sheng Li

According to Luoyang rainfall data from 1951 to 2011, this paper discussed the distribution characteristics of rainfall in the whole year. It analyzed summer maize growth period with the coupling of water consumption. It set up the estimation model of summer maize water consumption, the mathematical model of yield and water relationship, and then analyzed its mutual relations. The experimental results showed that the water requirement and rainfall distribution would fit well during summer maize growth. But summer maize growth stage should be irrigated suitably in the dry and median water year.


1997 ◽  
Vol 54 (spe) ◽  
pp. 39-44 ◽  
Author(s):  
D.A. Teruel ◽  
V. Barbieri ◽  
L.A. Ferraro Jr.

The knowledge of the Leaf Area Index (LAI) variation during the whole crop cycle is essential to the modeling of the plant growth and development and, consequently, of the crop yield. Sugarcane LAI evolution models were developed for different crop cycles, by adjusting observed LAI values and growing degree-days summation data on a power-exponential function. The resultant equations simulate adequately the LAI behavior during the entire crop cycle. The effect of different water stress levels was calculated in different growth periods, upon the LAI growth The LAI growth deficit was correlated with the ratio between actual evapotranspiration and máximum evapotranspiration, and a constant named kuu was obtained hi each situation. It was noticed that the kLAI must be estimated not Just for different growth periods, but also for different water stress levels in each growth period.


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