Economics of wheat as influenced by natural farming, organic farming and recommended package of practices

A field experiment was laid out on split-plot design with two uneven controls viz. four foliar concentrations of cow urine and jeevamrutha under natural farming which were compared with Organic farming (OF) and Recommended package of practices (RPP) given by UAS, Dharwad. The treatments were replicated thrice. The study revealed that RPP recorded significantly higher grain yield, straw yield, gross return, net return and B:C ratio than OF and natural farming practices. The grain yield reduction in the best treatment (cow urine @ 50 % + jeevamrutha @ 100 %) was 16 % lesser than RPP and 2 % higher than OF. However, the cost of cultivation in natural farming with cow urine @ 50 % + jeevamrutha @ 100 % was lesser to the extent of 6.91 and 30.42 % than RPP and OF. Our study indicates that the irrigated wheat can be grown under natural farming conditions profitably.

Implementation of iceplant production under semi-controlled conditions

Mesembryanthemum crystallinum is considered a drought and saline stress-tolerant plant with many biological activities that has been revalued as cool flavouring plant. The objective of this work was to assess optimum mode of cultivation of M. crystallinum to produce edible parts under greenhouse conditions. Therefore, three soilless media were evaluated: peat, vermiculite and hydroponic culture. Pot culture in peat did not result to be a good substrate for iceplant, with little biomass production. However, vermiculite and hydroponics allowed optimum growth of M. crystallinum, with a significantly greater yield in plants grown in vermiculite irrigated with nutrient solution. In fact, plants cultivated in vermiculite enhanced leaf area and leaf fresh weight, together with high foliar concentrations of N, Mg, Mn, Fe, Na, clorophylls and carotenoids. Furthermore, increased succulence and Na concentration of edible parts of glacier lettuce grown in vermiculite can offer more interesting taste, consistence and nutrient content for consumers. Higlights Hydroponic and vermiculite cultures led to optimum crystallinum growth. Peat pot culture did not seem to be an adequate substrate to cultivate crystallinum. Ice plants grown in vermiculite presented highest leaf fresh yield and high foliar N, Mg, Mn, Fe, Na, chlorophyll and carotenoid concentrations.

Impacts of Maternal Genotype on Pecan Seedling Performance in an Alkaline, Saline-sodic Soil

A field study was conducted to evaluate tolerance of pecan rootstocks to soil salinity and sodicity. Seven cultivars—Elliott, Giles, Ideal, Peruque, Riverside, ‘Shoshoni, and VC1-68—were selected from a range of geographic regions of origin. The soil of the experimental plot was a poorly drained, saline–sodic Pima silty clay variant. The irrigation water was a moderately saline mix of Gila River and local groundwater with an electrical conductivity of 2.8 dS⋅m–1, containing primarily ions of Na and Cl. Eighty seeds of each cultivar were planted in a greenhouse in late Feb. 2016; 48 seedlings of each cultivar were transplanted into field plots in Feb. 2017. Half the trees received a soil-based application of Zn–ethylenediaminetetraacetic acid (EDTA) at planting. The trees were observed and rated for both vigor and resistance to salt injury on seven separate occasions. Trunk diameter was measured each dormant season. Leaf samples were collected on 9 Oct. 2019 and 6 Oct. 2020, and were analyzed for nutrient content. Zn-EDTA was not found to have a significant effect on growth, vigor, or resistance to salt injury. ‘Elliott’ seedlings exhibited greater tolerance for the alkaline, saline–sodic soil conditions than other cultivars. ‘Giles’ and ‘Peruque’ were most severely affected. Resistance to salt injury (ranging from marginal leaf burn to necrosis of entire leaf), vigor, and growth correlated more strongly with foliar concentrations of Na than Cl or K during 2019. Vigor and growth were not significantly correlated with foliar Na, Cl, or K concentrations in 2020. The foliar K:Na ratio had a nearly equal correlation with resistance to salt injury and a greater correlation with growth than that of Na alone in 2019. However, although the correlation of the K:Na ratio with vigor was stronger than that of Cl or K, Na had the strongest correlation with vigor in 2019. In 2020, the only significant correlation of growth and vigor was with the K:Na ratio. The strongest correlation with resistance to salt injury in 2020 was with foliar Na concentration.

Red alder defense mechanisms against western tent caterpillar defoliation

Red alder (Alnus rubra Bong.) is a tree of high economic and ecological importance but subject to severe defoliation during episodic outbreaks of tent caterpillars (Malacosoma spp.). We evaluated variation in western tent caterpillar (M. californicum Packard, 1864) (WTC) resistance among and within red alder populations and clones, and investigated potential defense mechanisms. Bioassay feeding trials were conducted with WTC on 20 red alder clones from 10 provenances (two clones per provenance). Phenology and quality of red alder leaves were analyzed to determine if budburst, leaf chemical content, water content or physical traits are determinants of WTC preference. Alder clones differed in percent leaf area eaten by WTC and in leaf defense traits. The concentrations of total phenolics, condensed tannin and the diarylheptanoid oregonin negatively correlated with the percent leaf area eaten by the caterpillars, and a potential threshold was observed, above which the concentration of each of the chemicals appeared to reduce WTC feeding. Particularly, foliar concentrations of oregonin greater than 20 % of leaf dry weight were consistently associated with reduced feeding. The effects of oregonin concentration in red alder leaves on tent caterpillar feeding is a novel finding.

Frequency distribution of foliar nickel is bimodal in the ultramafic flora of Kinabalu Park (Sabah, Malaysia)

Background and Aims The aim of this study was to test the frequency distributions of foliar elements from a large dataset from Kinabalu Park (Sabah, Malaysia) for departure from unimodality, indicative of a distinct ecophysiological response associated with hyperaccumulation. Methods We collected foliar samples (n = 1533) comprising 90 families, 198 genera and 495 plant species from ultramafic soils, further foliar samples (n = 177) comprising 45 families, 80 genera and 120 species from non-ultramafic soils and corresponding soil samples (n = 393 from ultramafic soils and n = 66 from non-ultramafic soils) from Kinabalu Park (Sabah, Malaysia). The data were geographically (Kinabalu Park) and edaphically (ultramafic soils) constrained. The inclusion of a relatively high proportion (approx. 14 %) of samples from hyperaccumulator species [with foliar concentrations of aluminium and nickel (Ni) >1000 μg g–1, cobalt, copper, chromium and zinc >300 μg g–1 or manganese (Mn) >10 mg g–1] allowed for hypothesis testing. Key Results Frequency distribution graphs for most elements [calcium (Ca), magnesium (Mg) and phosphorus (P)] were unimodal, although some were skewed left (Mg and Mn). The Ni frequency distribution was bimodal and the separation point for the two modes was between 250 and 850 μg g–1. Conclusions Accounting for statistical probability, the established empirical threshold value (>1000 μg g–1) remains appropriate. The two discrete modes for Ni indicate ecophysiologically distinct behaviour in plants growing in similar soils. This response is in contrast to Mn, which forms the tail of a continuous (approximately log-normal) distribution, suggestive of an extension of normal physiological processes.

Seasonal changes in eastern hemlock (Tsuga canadensis) foliar chemistry

Eastern hemlock (Tsuga canadensis (L.) Carrière) is an eastern North American conifer threatened by the invasive hemlock woolly adelgid (Adelges tsugae Annand). Changes in foliar terpenes and phenolics were evaluated in new (current-year growth) and mature (1-year-old growth) hemlock needles during the growing season and into plant dormancy. From April through September, foliar concentrations of nonvolatile soluble phenolics, condensed tannins, lignin, mono- and sesquiterpenes, α-pinene, camphene, isobornyl acetate, and diterpene resin were quantified. After September, additional analyses of metabolites that continued to differ significantly between new and mature foliage were carried out. Total soluble phenolic and condensed tannin concentrations in new foliage remained low relative to those of mature foliage throughout the growing season and converged in December. Lignin concentration in new foliage converged with that of mature foliage by July. Concentrations of α-pinene, camphene, isobornyl acetate, and diterpene resin in new foliage converged with those of mature foliage within 1 month of budbreak. The convergence of terpene concentrations in new and mature foliage suggests that these metabolites may play a role in herbivore defense during the peak growing season. Conversely, soluble phenolics, including condensed tannins, may defend foliage from herbivory outside of the spring growth period.

Nutrient dilution and climate cycles underlie declines in a dominant insect herbivore

Evidence for global insect declines mounts, increasing our need to understand underlying mechanisms. We test the nutrient dilution (ND) hypothesis—the decreasing concentration of essential dietary minerals with increasing plant productivity—that particularly targets insect herbivores. Nutrient dilution can result from increased plant biomass due to climate or CO2 enrichment. Additionally, when considering long-term trends driven by climate, one must account for large-scale oscillations including El Niño Southern Oscillation (ENSO), North Atlantic Oscillation (NAO), and Pacific Decadal Oscillation (PDO). We combine long-term datasets of grasshopper abundance, climate, plant biomass, and end-of-season foliar elemental content to examine potential drivers of abundance cycles and trends of this dominant herbivore. Annual grasshopper abundances in 16- and 22-y time series from a Kansas prairie revealed both 5-y cycles and declines of 2.1–2.7%/y. Climate cycle indices of spring ENSO, summer NAO, and winter or spring PDO accounted for 40–54% of the variation in grasshopper abundance, mediated by effects of weather and host plants. Consistent with ND, grass biomass doubled and foliar concentrations of N, P, K, and Na—nutrients which limit grasshopper abundance—declined over the same period. The decline in plant nutrients accounted for 25% of the variation in grasshopper abundance over two decades. Thus a warming, wetter, more CO2-enriched world will likely contribute to declines in insect herbivores by depleting nutrients from their already nutrient-poor diet. Unlike other potential drivers of insect declines—habitat loss, light and chemical pollution—ND may be widespread in remaining natural areas.

FOLIAR COMPOSITION OF Eucalyptus urograndis IN TWO SITES FERTILIZED WITH N, P AND K IN SOUTHERN BRAZIL

The leaf composition has been used as a tool in establishing the nutritional diagnosis and evaluation of the effectiveness of the use of nutrients. This knowledge is still scarce in subtropical conditions of cultivation. In this sense, the study aims to evaluate the effect of N, P and K fertilization on leaf concentration of Eucalyptus urograndis. The experiments were installed in the Oxisols of the sandy-loam texture, in the counties of Jaguariaíva and Ventania, state of Paraná. In the N and P experiments, the following doses: 0; 30; 60; 120 and 240 kg ha-1 of N and P2O5; and 0; 35; 70; 140 and 280 kg ha-1 K2O, split in four applications: during planting and side dressing at 3, 9 and 12 months of age. The response was evaluated according to the nutritional status of the plants at 12, 24 and 36 months, by foliar concentration. It also evaluated levels of K deficiency plant through visual and chemical analysis. The application of N and P did not result in alteration in the leaf contents of the same in all evaluated periods and in the two regions, with a slight decrease in the concentrations with time. A different effect occurred with K at the Jaguariaíva site, which altered its foliar concentration at the 24th and 36th month, and increased foliar concentrations with time. These effects demonstrate that foliar diagnosis, through foliar concentrations, may present limitations of interpretation and should not be evaluated separately for fertilization recommendation.