The fertiliser that is applied between maize (Zea mays L.) plants via furrow application cannot be completely absorbed and used because of the wide planting space, resulting in fertiliser wastage and soil pollution. To address this issue, we proposed an intermittent fertilisation method for single maize plant seeding, and designed a fertilisation device that can control the intermittent timing and duration of fertiliser application. A simple indoor bench test was done to verify the feasibility of the device. A synchronised control model of the seed and fertiliser was also established. Thus, a quantitative precision intermittent fertilisation system for a single maize plant was developed. The technique was integrated and applied in a current mainstream quantitative precision seeder and fertiliser feeder for maize in field trials. The trial results showed that the average centre distance between the seed and the fertiliser was 5-8 cm and the qualification rate was >90%. The effective length of fertilisation was about one-third of plant spacing, and the largest coefficient of variation was 12.37%. In conclusion, the present quantitative precision interval fertilisation system can feed and apply fertiliser to the predetermined fertiliser site of maize plants, realising the ‘one seed and one fertiliser' seeding and fertilisation mode, which reduced the fertiliser application amount and increased the fertiliser utilisation rate.

Context. Infecting grasses with an Epichloë endophyte contribute significantly to host plant salt tolerance. The Epichloë endophyte alkaloid peramine is primarily responsible for feeding deterrence against some herbivorous insects. Infection by an Epichloë is required for peramine production in the host grass. Limited information is available regarding the effects of salinity stress on Epichloë endophyte colonisation and associated production of peramine metabolites.

Aims and methods. In this study, we determined the effects of NaCl stress on the concentration of endophytic hyphae and peramine in wild barley (Hordeum brevisubulatum (Trin.) Link) seedlings infected with Epichloë bromicola.

Key results. Seedings dry weight at 4 weeks declined from 7.05 to 4.27 g/plant over the range, 0-300 mM NaCl. The hyphal concentration, as well as the peramine concentration, increased in response to high NaCl concentrations, hyphae and peramine concentration at 4 weeks increased from 13.29 to 264.60 copies/ng gDNA and from 26.75 to 43.19 μg/g DW, respectively. Peramine concentration was positively correlated with the concentration of hyphae (R² = 0.4012, P < 0.001).

Conclusions and implications. It seems that peramine concentration was mostly explained by the in-planta variation in endophyte hyphae concentration in wild barley infected with Epichloë species under highly saline conditions.

As the major source of edible protein and oil, the global demand for soybean (Glycine max (L.) Merr.) is increasing. Plant height is closely related to yield; therefore, understanding the genetic basis of plant height will help to improve soybean plant type and increase seed yield. In this study, quantitative trait loci (QTLs) and nucleotides (QTNs) for soybean plant height were detected by linkage analysis and association analysis. A high-density map containing 2225 bin markers was constructed by using 108 342 SNPs of a recombinant inbred line population (named RIL3613) of 120 lines for linkage analysis. In total, 39 QTLs were detected, including 16 QTLs that were repeatedly detected in multiple environments. Association analysis was performed by using 63 306 SNPs from a germplasm population of 455 natural soybean accessions. In total, 62 QTNs were detected, and 26 QTNs were repeatedly detected by multiple methods. Fourteen QTNs were distributed in the intervals of six multiple-environment QTLs by comparing the results of association analysis and linkage analysis. With pathway analysis, six candidate genes were identified as being associated with plant height. These results contribute to analysis of the genetic basis of plant height and will promote marker-assisted selection for breeding ideal plant shape.

The soybean cyst nematode (SCN, Heterodera glycine Ichinohe) is a major disease affecting soybean (Glycine max (L.) Merr.) production and yield. Breeding of new SCN-resistant cultivars and understanding their resistance mechanisms are valuable for improving SCN resistance of soybean. However, we still know little about resistance mechanisms to SCN. The purpose of our analysis was to understand the different resistance mechanisms of resistant and susceptible lines to SCN by dissecting their transcriptional changes during infection by SCN HG type 1.2.3.5.7. In this study, 119 recombinant inbred lines derived from a cross of cv. Dongnong L-204 (SCN resistant) and cv. Heinong 37 (SCN susceptible) were identified for resistance status to SCN HG type 1.2.3.5.7. Roots of the lines identified as extremely resistant or susceptible (L5, L89) were sequenced by transcriptome, and we obtained 66.61 Gb of data. Compared with the untreated control, there were 8394 and 6899 differentially expressed genes in SCN-infected roots of L5 and L89, respectively. Genes of metabolic pathways, biosynthesis of secondary metabolites, plant hormone signal transduction, and plant-pathogen interaction pathway were significantly expressed in both resistant and susceptible genotypes. The expression of genes of phenylpropanoid biosynthesis, flavonoid biosynthesis, thiamine metabolism, cutin, suberin and wax biosynthesis, and endocytosis pathway was significantly higher in the resistant line than the susceptible line. Transcription factor analysis showed that 88 transcription factors from 18 transcription factor families responded to SCN stress. Nine genes were identified by reverse transcriptase qPCR to be associated with SCN resistance. This study helps us to understand better the mechanism of soybean resistance to SCN.

The diverse microclimatic belts of the Western Himalayan region of India are considered hot spots for genetic diversity of common bean (Phaseolus vulgaris L.). Western Himalayan beans are known for various agronomically superior/important traits including unique aroma, taste and cooking quality. In the present study, 25 unlinked genomic simple sequence repeat (SSR) markers distributed across the common bean genome were used to assess the genetic/allelic diversity among and within populations belonging to the Jammu and Kashmir regions of the Western Himalayas. These two regions are considered most important hot-spots for common bean diversity in western-Himalayas. The analysis of genotypic data of SSR markers revealed a total of 263 alleles with an average of 10.52 alleles per locus. The genetic diversity analysis revealed higher variability in bean landraces belonging to Jammu region (H_e = 0.73) as compared to genotypes from Kashmir region (H_e = 0.647) and some exotic genotypes (0.71). The genotypes were also phenotyped for four important nutritional traits and the analysis of trait data revealed that sugar content was highest in common bean genotypes from Jammu region, while protein, starch and phenol content were highest in exotic common bean genotypes. Therefore, the superiority of common bean germplasm from Jammu region may be due to a higher level of allelic diversity, more private alleles and higher sugar content. The diverse genotypes based on genotypic data and trait performance will prove useful in future breeding programs aimed at enhancing nutritional contents of common bean varieties.

Context. The removal of phosphorus (P) in harvested grain and poor recycling of P creates unique concerns for farming systems that aim to reduce reliance on non-renewable fertiliser inputs, such as ‘regenerative' farming systems, or for organic grain growers for whom synthetic P inputs are prohibited.

Aims and methods. We examine gross P budgets across the Australian cropping landscape and explore implications for the land area that could be potentially cropped if all P removed in harvested produce was replaced using domestic recycled P sources.

Key results. Major cereal, pulse and oilseed crops occupied 21.7 million ha year^-1 on average from 2000 to 2018, removing around 136 274 t P year^-1. The 27 200 t P in captured animal manure could only sustain around 20% of this area. A further 23%, around 4.9 million ha, could be sustained from sewage and greenwaste resources, but potential pathogens/contaminants limit their current use on organic farmland, and on other farmland when contaminant levels exceed thresholds.

Conclusions. Development of technologies acceptable to organic certifying agencies to extract P from sewage and greenwaste would expand available resources for organic and regenerative farming and would enable systems to move further towards closed loop nutrient cycling. Ultimately, export of grain overseas results in a large deficit between the 136 000 t P removed annually from fields and domestic recyclable P (around 74 000 t P year^-1).

Implications. Apart from importing rock phosphate-based P or recycled P products, this deficit could only be overcome in the long term by reducing grain exports, or by reducing the concentration of P in exported grain.

Context. Integrated crop-livestock-forestry systems can be an alternative to monoculture pastures; however, the effect of the arboreal component on tillering and tussock dynamics of understorey grass canopy is not well understood.

Aims. Our objective was to evaluate the patterns of tillering dynamics, population stability and tussock distribution of Piatã palisadegrass (Urochloa brizantha) as affected by contrasting shading regimes in the Brazilian Amazon biome.

Methods. The following three shading regimes were assessed: pasture with no trees (no shading, NS), moderate shading (MS, 338 trees ha^-1), and intense shading (IS, 714 trees ha^-1). Pastures were rotationally grazed by dairy heifers. Paddocks from MS and IS were stratified into three sampling strips, including two closer to the tree rows (i.e. lateral) and one between the two lateral strips (i.e. central). Two methods for monitoring sward canopy light interception (LI) were used for IS regime, namely, LI taken under the tree canopy (i.e. inside) and LI was taken above the tree canopy (i.e. outside).

Key results. Relative to NS, there was a reduction in photosynthetically active radiation transmittance of 18.1% and 37.1% on MS and 49.9% and 52.0% on IS for central and lateral shading strips respectively. Overall, the increase in shading level was associated with a decrease in average tussock perimeter, tiller population density, and an increase in the frequency of bare ground.

Conclusions. Our findings clearly indicate the key role of the light environment as a determinant of Piatã palisadegrass horizontal structure.

Implications. It highlights the importance of planning the levels of tree density and layout in areas of crop-livestock-forestry integration.

Potassium (K) fertilisation at planting time may not be sufficient to achieve high cassava yields. Experiments were conducted over two growing periods using sweet cassava (SC) variety IAC 576-70 and bitter cassava (BC) variety IAC 13 aiming to evaluate the effects of K fertilisation rate (0-150 kg K/ha) and timing of application (one, two, or three) on leaf K concentration, yield components, and storage-root and starch yields. The SC and BC varieties were grown in a randomized block design in a 3 × 4 + 1 factorial scheme with four replications during growing periods of 10 and 20 months respectively. For SC, split application of K at planting plus 3 months after planting (MP) or at planting plus 1.5 and 3 MP was more effective at increasing the marketable root yield, with greater rainfall at the beginning of the growing period. Split application of K at planting plus 3 MP also reduced the cooking time and cooked root firmness. For BC, split application of K at planting plus 12 MP more effectively increased the storage-root and starch yields; however, root yield response to K fertilisation in the second growing period, with greater rain intensity during the initial crop stages, was greater than in the first growing period. In K-deficient soils, the optimal K application rate for SC marketable root yield varied from 79 to 111 kg/ha when K was applied after 1.5 MP, and linear responses to K application rate occurred when K was applied earlier. For BC, the optimal K application rate varied from 75 to 92 kg K/ha. Our data suggest that K application times should be different for cassava varieties with short and long growing periods.

Phenylalanine ammonia lyase (PAL) is the first enzyme in the phenylpropanoid pathway and plays a critical role in plant growth, development and stress defence. However, there have been few reports of the PAL gene family in lucerne (also known as alfalfa, Medicago sativa L.), one of the most important forage legume species worldwide. In this study, we report that PAL in lucerne is encoded by a family of seven genes: MsPAL1-MsPAL7. Furthermore, a comprehensive genome-wide bioinformatics analysis of the MsPAL gene family is presented, including chromosomal locations, phylogenetic relationships, gene structures and conserved motifs. The cis-elements and potential biological functions of these genes were investigated, revealing the potential roles of MsPAL members in response to various stresses. RT-qPCR results showed that the expression of MsPAL6 was significantly upregulated under both salinity- and waterlogging-stress conditions. Other MsPAL members such as MsPAL1 and MsPAL2 were downregulated under saline conditions and upregulated significantly after waterlogging stress. Our findings provide useful information for further practical analyses and for the genetic improvement of abiotic stress tolerance of lucerne.