Nitrogen, phosphorus, water and sediment losses under sugarcane (Saccharum spp.) and peanut (Arachis hypogaea l.) cultivation

Sertãozinho-SP is a major world producer of sugarcane and peanuts. The crop rotation technique recovers soils and brings commercial benefits to producers. Objective: to determine the losses of water, nitrogen (N), phosphorus (P) and sediments, due to the use and occupation of the soil in the peanut and sugarcane crop, using the SWAT model, maintaining the topographic and physical attributes and climatic conditions of the Mogi-Guaçu River sub-watershed, in the Sertãozinho city – SP. To carry out this study, local data from digital elevation maps and soil pedological maps, precipitation, wind, solar radiation, and relative humidity were used. The actual accumulated evapotranspiration was higher in sugarcane (906.7 mm) when compared to peanuts (886.1 mm). Sediment losses were higher in peanuts (300.66 mm) when compared to sugarcane (280.69 mm), as well as losses of N (118.44 and 34.48 kg ha-1) and P (5.456 and 0.805 kg ha-1), respectively. It is concluded that the peanut crop showed the greatest losses of water, nutrients, and sediments, when compared to sugarcane, showing that the land cover directly influenced these losses. Studies like these can aid in decision-making about environmental policies, helping with soil and water conservation in Brazilian sub-watershed.

Biological Control of Charcoal Rot in Peanut Crop through Strains of Trichoderma spp., in Puebla, Mexico

Charcoal rot is an emerging disease for peanut crops caused by the fungus Macrophomina phaseolina. In Mexico, peanut crop represents an important productive activity for various rural areas; however, charcoal rot affects producers economically. The objectives of this research were: (a) to identify and morphologically characterize the strain “PUE 4.0” associated with charcoal rot of peanut crops from Buenavista de Benito Juárez, belonging to the municipality of Chietla in Puebla, Mexico; (b) determine the in vitro and in vivo antagonist activity of five Trichoderma species on M. phaseolina, and (c) determine the effect of the incidence of the disease on peanut production in the field. Vegetable tissue samples were collected from peanut crops in Puebla, Mexico with the presence of symptoms of charcoal rot at the stem and root level. The “PUE 4.0” strain presented 100% identity with M. phaseolina, the cause of charcoal rot in peanut crops from Buenavista de Benito Juárez. T. koningiopsis (T-K11) showed the highest development rate, the best growth speed, and the highest percentage of radial growth inhibition (PIRG) over M. phaseolina (71.11%) under in vitro conditions, in addition, T. koningiopsis (T-K11) showed higher production (1.60 ± 0.01 t/ha−1) and lower incidence of charcoal rot under field conditions. The lowest production with the highest incidence of the disease occurred in plants inoculated only with M. phaseolina (0.67 ± 0.01 t/ha−1) where elongated reddish-brown lesions were observed that covered 40% of the total surface of the main root.

Assessment of maize-peanut intercropping and its potential waste usage for cattle feed in dry land

Intercropping planting system is one of methods to enhance the land productivity. The maize and peanut crops waste has high beneficial to farmers for cattle feed. The study of maize and peanut crops intercropping has been conducted in May-August 2020. Study was arranged by using Randomized Complete Block Design with 5 treatments and replicated for 8 times. Treatments examined were P1: Srikandi Kuning maize variety cultivated by monoculture planting system; P2: Nasa 29 maize variety cultivated by monoculture; P3: Peanut crop cultivated by monoculture; P4: Srikandi Kuning and peanut crop cultivated by intercropping; P5: Nasa 29 and peanut crop cultivated by intercropping. Variables observed were growth and yield components and analysed by analysis of variance and advanced tested by LSD at 5%. To know the land productivity, the calculation of Land Equivalent Ratio (LER) was done meanwhile the Index of Plant Competition (IPC) also was calculated to know the plant competition level. Results showed that the peanut crop productivity by intercropping was decrease about 37.50%-38.79% compared to monoculture. Meanwhile, the productivity of Srikandi Kuning maize variety was also decrease due to the reducing of plant population. The intercropping of Srikandi Kuning and Nasa 29 variety with peanut crop enhance the LER became 1.02 and 1.03. The utilization of Nasa 29 maize variety by intercropping with peanut crop was better than Srikandi Kuning with the lower IPC namely 0.8932 meanwhile the IPC of Srikandi Kuning was 0.9270. The potential waste for cattle feed at maize crop plantation by monoculture was higher than intercropping with peanut crop and peanut crops by monoculture namely P3: 572 head/ha; P1: 500 head/ha; P5: 484 head/ha; P4: 454 head/day; P3: 288 head/day.

Legacy genetics of Arachis cardenasii in the peanut crop shows the profound benefits of international seed exchange

The narrow genetics of most crops is a fundamental vulnerability to food security. This makes wild crop relatives a strategic resource of genetic diversity that can be used for crop improvement and adaptation to new agricultural challenges. Here, we uncover the contribution of one wild species accession, Arachis cardenasii GKP 10017, to the peanut crop (Arachis hypogaea) that was initiated by complex hybridizations in the 1960s and propagated by international seed exchange. However, until this study, the global scale of the dispersal of genetic contributions from this wild accession had been obscured by the multiple germplasm transfers, breeding cycles, and unrecorded genetic mixing between lineages that had occurred over the years. By genetic analysis and pedigree research, we identified A. cardenasii–enhanced, disease-resistant cultivars in Africa, Asia, Oceania, and the Americas. These cultivars provide widespread improved food security and environmental and economic benefits. This study emphasizes the importance of wild species and collaborative networks of international expertise for crop improvement. However, it also highlights the consequences of the implementation of a patchwork of restrictive national laws and sea changes in attitudes regarding germplasm that followed in the wake of the Convention on Biological Diversity. Today, the botanical collections and multiple seed exchanges which enable benefits such as those revealed by this study are drastically reduced. The research reported here underscores the vital importance of ready access to germplasm in ensuring long-term world food security.

Peanut yield under irrigation levels in off-season cultivation

Water deficit is considered the most critical environmental factor for peanut production in Brazil, as it constitutes one of the major constraints to the expansion of its cultivation in the suitable crop zones of the country. Determining crop water demand is fundamental to increasing yield with lower water consumption. The present study aimed to evaluate the effects of full and deficit irrigation levels (L1 = 8%, L2 = 27%, L3 = 63%, L4 = 94% and L5 = 100% replenishment of crop evapotranspiration) on the development, growth and yield of peanut crop sown in two times, February and March. Treatments were distributed in a split-plot randomized complete block design, with four replicates, using a line-source sprinkler system. Irrigation depths from 65 to 314 mm were applied with the levels L1 to L5 during the first and second cropping cycles. Full irrigation with sowing in March was more advantageous due to yield increase of up to 30% compared to sowing in February, but crop cycle was 25 days longer. Water stress caused by deficit irrigation reduced plant height, seed mass and pod yield, while full irrigation (L5) led to yields from 4,141 to 5,102 kg ha-1 for February and March, approximately three times higher than those obtained with the lowest irrigation level (L1). Highlights Peanut has great importance in the food and industry of several countries. The results of this research apply to regions that require irrigation, which is of about 70% of the areas of the globe with this legume. This paper contributes with information that emphasizes the possibility of cultivation in the drought season, aiming at the expansion of the crop and the production of quality seeds using irrigation.

Development and validation of diagrammatic scales to evaluate damage by the two-spotted spider mite (Tetranychus urticae) in peanut

Argentina is the second largest peanut (Arachis hypogaea L.) exporter in the world. The main peanut pest in our country is the two-spotted spider mite (Tetranychus urticae Koch 1836). To date, there is no validated method to quantify this pest. The aim of this work was to develop and validate a logarithmic diagrammatic scale to assess damage by the two-spotted spider mite in peanut. In 2015-16, 200 leaflets were collected from a plot infested with the pest. Damaged leaf area (DLA) was calculated using SisCob software. Six-, seven-, eight- and nine-class scales were proposed. Mean values for each class and scale were obtained with 2-LOG. Leaflets were analyzed by 13 raters who used the four proposed scales. Precision and accuracy were determined by simple linear regression between the DLA and estimated damaged leaf area. Reproducibility was determined by linear regression between estimates of raters combined in pairs. The seven-class scale was the best validated one for all the parameters. Most raters showed constant deviations and overestimated DLA, whereas only one rater presented systematic deviations. This seven-class scale is the first developed and validated one to evaluate two-spotted spider mite damage to peanut in Argentina. Highlights According to the validation results, the seven-class diagrammatic scale was the best one in terms of accuracy, precision and reproducibility with values above 0.80, 0.75 and 0.75 respectively. The scales are useful tools for pest assessment, fundamental parameters for integrated pest management. The seven-class scale is the first one developed and validated for evaluating damage by the two-spotted spider mite in peanut crop in Argentina. With this scale a loss function will be calculate which will allow the estimation of the EIL of this pest.

The Effect of Top G2 Liquid Organic Fertilizer and SP-36 Fertilizer on Peanut Plant Growth and Yield

The purpose of this study is to find out the effect of the administration of Top G2 liquid organic fertilizer and SP-36 fertilizer on peanut crop yields, to know the dose of SP-36 fertilizer and Top G2 liquid organic fertilizer that can produce the best peanut crop results and to know the interaction of liquid organic fertilizer Top G2 and SP-36 fertilizer in improving the yield of peanut crops. The design used in this study is a Randomized Group Design (RGD) factorial pattern. This treatment consists of two factors: First Factor: Concentration of POC Top G2 consisting of OC0: No POC Top G2, OC1: POC Top G2 4 cc ltr air-1petak-1 OC2: POC Top G2 8 cc ltr water-1Swath-1; The second factor: Fertilizer Dose P (SP36) consists of P0: Without SP36 fertilizer; P1: 300 kg ha-1; Q2: 400 kg ha-1. The results showed that the administration of g2 top liquid organic fertilizer with a concentration of 8 cc ltr water-1 produced the highest plant height of 20.75 cm tan-1, the number of leaves 27.36 strands of tan-1, the number of pods 39.89 tan-1 and the harvest index 0.326. The interaction of g2 top liquid organic fertilizer and phosphorus fertilizer increases the weight of dried seeds harvesting crops, i.e. in the treatment of liquid fertilizer concentration top G2 8 cc ltr water-1 plot-1 with a seed weight of 235 g tan-1. Cultivation of peanut crops should use liquid organic fertilizer top G2 concentration eight cc tr water-1 tile-1 and need further research using higher concentrations of liquid organic fertilizer top G2 to see the optimum needs of peanut crops.

ValSten: a new wild species derived allotetraploid for increasing genetic diversity of the peanut crop (Arachis hypogaea L.)

Introgression of desirable traits from wild relatives plays an important role in crop improvement, as wild species have important characters such as high resistance to pests and pathogens. However, use of wild peanut relatives is challenging because almost all wild species are diploid and sexually incompatible with cultivated peanut, which is tetraploid (AABB genome type; 2n = 4x = 40). To overcome the ploidy barrier, we used 2 wild species to make a tetraploid with the same allotetraploid genome composition as cultivated peanut. Crosses were made between 2 diploid wild species, Arachis valida Krapov. and W.C. Greg. (BB genome; 2n = 2x = 20) and Arachis stenosperma Krapov. and W.C. Greg. (AA genome; 2n = 2x = 20). Cuttings from the diploid F1 AB hybrid were treated with colchicine to induce chromosome doubling thus generating an induced allotetraploid. Chromosome counts confirmed polyploidy (AABB genome; 2n = 4x = 40). We named the new allotetraploid ValSten. Plants had well-developed fertile pollen, produced abundant seed and were sexually compatible with cultivated peanut. ValSten exhibits the same high resistance to early and late leaf spot and rust as its diploid parents. Notably, we observed morphological variations, including flower width and branch angles in the earliest generation (S0) of allotetraploids. A SNP array was used to genotype 47 S0 allotetraploids. The great majority of markers showed the additive allelic state from both parents (AABB). However, some loci were AAAA or BBBB, indicating homeologous recombination. ValSten provides a new, vigorous, highly fertile, disease resistant germplasm for peanut research and improvement.

Broadening the Variability for Peanut Breeding with a Wild Species-Derived Induced Allotetraploid

The use of wild species in peanut breeding provides remarkable opportunities for introducing new traits to the peanut crop and it has increased in recent years. Here, we report the morphological and agronomic, including disease resistance, variation observed in 87 Recombinant Inbred Lines (RILs) that were derived from the wild ancestors of peanut and the cultivar Runner IAC-886. These lines exhibited a wide range of variation for these traits, with transgressive segregation and novel phenotypes being observed in many lines. Quantitative Trait Loci (QTLs) for agronomic and resistance traits were detected. Six RILs with contrasting phenotypes for agronomic traits and moderate resistance to leaf spots were genotyped. All of the lines had, on average, 50% wild alleles, with at least one large wild segment and multiple interspersed alleles in all of the chromosomes. Genetic exchange between subgenomes was observed. On four lines, the top of Chr 05/15, which is tetrasomic AAAA in A. hypogaea, has been restored to its AABB state by the introgression of A. ipaënsis alleles. We identified lines with good agronomic traits while harboring genome composition and structure completely different from each other and from the cultivated peanut. The variation that is observed for the fruit type is also important for a better comprehension of the domestication process in peanut. This increase in genetic diversity has great potential benefits for the peanut breeding programs.