Crop and Pasture Science
Volume 71
Numbers 11 & 12 2020
No-till is an important component of conservation agriculture globally, but occasional strategic tillage may be required to deal with agronomic issues that can arise. We demonstrate no lasting impacts of a single tillage on crop production or soil conditions. Strategic tillage can form part of a productive and sustainable cropping system.
We used a series of 27 nutrient-response experiments to derive soil-test critical values for wheat and canola in the high-rainfall zone of southern Australia. Critical values were higher than those from lower rainfall regions of Australia. The Sprengel–Lieberg Law of the Minimum overestimated yields where there were multiple nutrient deficiencies.
Sowing date affects the environmental conditions experienced during maize development, which modifies maize response to nitrogen (N) fertilisation, depending on the hybrid cycle. The use of increasing rates of topdressed N enhances maize capacity to intercept solar radiation and to convert it into grain production. The use of high rates of N is an adequate management strategy to increase the yield when the crop is sown at the beginning of spring.
SMV is a worldwide soybean disease that can cause serious reduction in yield and seed quality; however, the mechanism underlying SMV resistance is not clear. We applied transcriptome analysis of a pair of near-isogenic lines from Chinese cultivars Qihuang-1(R) and Nannong 1138-2(r). Some genes and networks in Qihuang-1 that are regulated by R-mediated resistance were discovered.
With the aim of further clarifying the genetic mechanisms of oil content and composition of soybeans, we developed a mapping strategy by integrating RNA-Seq and bioinformatics approaches and a GWAS database. Two pathways (fatty acid elongation, desaturation and export from plastid; and triacylglycerol biosynthesis) potentially affect oil accumulation, and the genes LOX, CYP93D1, GPT2, SAD, FAD2, FAD2, CYP89A6 and GPT2 stood out as candidates. This study provides an efficient way to uncover candidate genes for oil accumulation.
Increasing production of oilseed rape is limited by the improvement of population quality. In this study, fertilising level had more influence than planting density on increasing oil seed and protein yields per ha. Increasing fertilisation rates significantly increased seed protein content (%), simultaneously slightly decreasing seed oil and glucosinolate contents, whereas erucic and oleic acid contents were unaffected, suggesting that a balanced application of NPKBS fertilisers should be employed in direct sowing cultivation of oilseed rape.
Growing two or more crops on the same field (intercropping) is a major production strategy in the tropics, and is often used to address food insecurity. Our study evaluated the performance of intercropping mixtures of sesame and sunflower under an organic system. The two sesame varieties intercropped with sunflower sown at the same time or 10 days after sowing of sesame demonstrated high land-use efficiency, crop compatibility and high intercrop productivity and economic efficiency, especially when organic fertiliser was applied.
Hybrid sterility constrains the application of interspecific genetic resources in breeding. Microsporocytes, microspores, pollen grains and anthers of male-sterile hybrids of Nicotiana were examined for cytological abnormalities, with findings including impaired membrane structures, cytomixis, asymmetrical callose wall formation, loss of chromosomes, nucleus and cytoplasm, vacuous pollen, irregular tapetum degradation and sporopollenin deposition. These findings will facilitate the application of Tomato spotted wilt virus-resistant resources in cultivated Nicotiana species through hybrid fertility restoration and backcross breeding.
Lack of availability of quality seed is prime hindrance to high production of cotton in developing countries. Moisture is a main culprit behind poor seed quality during harvesting and post-harvest handling. In this study, early harvest, use of zeolite beads in post-harvest drying, and hermetic storage preserved cottonseed quality.
Achnatherum inebrians is an invasive grass, and it is becoming increasingly widespread in natural grasslands of north-west China. We found that the Epichloë gansuensis endophyte played an important role in rhizosphere bacterial diversity, and nutrient accumulation and ratios of host A. inebrians. This work provides new understanding of the complex interactions that can occur between plants and endophytes.
This study compared the nitrogen-use efficiency (NUE) of urea applied as a foliar spray with that of the granular form in a subtropical climate. NUE was similar for both methods of application when applied to kikuyu (Cenchrus clandestinus) and short-rotation ryegrass (Lolium multiflorum) pastures. This was considered to be in part due to low tiller density and hence smaller leaf regrowth canopy for collecting the foliar spray than in temperate dairy regions.