Crops, Volume 2, Issue 3 (September 2022) – 9 articles

Osmotic stress enhances fruit quality, including the dry matter content, in tomatoes (Solanum lycopersicum L.). This study aimed at providing further insight into the precision control of fruit yield and quality on the long-term moderate osmotic stress conditions in tomato fruit production. We compared the growth pattern between fruits of two cultivars, typical Japanese and Dutch cultivars, under two different nutrient concentrations (2.3 and 5.0 dS·m⁻¹) to understand the effect of electrical conductivity (EC) on dry mass and water content of fruits. The experiment was performed with a rockwool bag culture system in a controlled greenhouse. Increasing EC resulted in an approximately 20% decrease in fruit yield and a 0.5–1% increase in fruit dry matter content in both cultivars. This yield reduction was not caused by the fruit number, but by an approximately 25% decrease in individual fresh fruit weight. Non-linear models were used to describe the changes in dry matter content, water content, and dry weight of tomato fruit as a function of cumulative temperature. The decay rate of dry matter content in the fruit decreased with high EC treatments in the Japanese cultivar. The points at which the rates of changes in water and dry weight increased the in fruit were around 585 and 480 °C-days after anthesis, respectively, under the low EC condition. Rates of water increase in the fruit were changed by high EC treatment, while the shifts were opposite with respect to the cultivars. Dry weight increase in the fruit was not affected by EC treatment. Collectively, our findings clarify the effect of EC on the fruit growth characteristics of Japanese and Dutch tomato cultivars, and provide new insights into the yield of high-Brix tomato cultivation. Full article

High salt concentration in irrigation water is often a limiting factor to tomato production in Brazil. However, there is limited information available regarding the tolerance of tomato genotypes to saline irrigation. An experiment was conducted in a protected environment using a randomized block design with four replications. Treatments consisted of 12 tomato genotypes cultivated in an environment with varying levels of salt stress. Moderate and severe salt stress affected plant height, transversal and longitudinal diameter of fruit, fresh mass, yield, and number of tomato fruit per plant. Cluster analysis, stability, and adaptability provided the best estimates to identify the most adaptable genotype to saline stress, with the genotypes Maestrina, Onix, Pizzadoro, and Shanty being the best adapted to moderate and severe saline stress conditions. The genotypes Maestrina, Onix, Pizzadoro, and Shanty were identified as most adaptable to and stable under salt stress. Sodium absorption increased as irrigation salinity increased. In addition, P, K, and Ca concentration decreased under salt stress, which caused damage to all yield components and plant nutrition. The genotype Onix was more tolerant to the effects of moderate saline irrigation, while the genotypes Sheena, Sperare, Santa Clara, IPA 6, and Dominador had lower losses under severe salt stress conditions. Full article

The adoption of food crops as a source of dietary macro- and micro-nutrients is a sustainable way to promote diet biodiversity and health while being respectful to the environment. The aim of this work was to comprehensively characterize the nutrient and phytochemical content of buckwheat seeds (Fagopyrum esculentum) and assess their physical properties for the evaluation of their suitability as food ingredients. The buckwheat samples were found to be complete sources of amino acids (UPLC-TUV analysis), with a protein content between 11.71 ± 0.40% and 14.13 ± 0.50% (Vario Max CN analysis), and a source of insoluble fiber with 11.05 ± 0.25 %, in the UK hulled samples (GC analysis). The buckwheat samples were rich in phosphorus, manganese, molybdenum, zinc, magnesium, and selenium (ICP-MS analysis). A total of 196 plant metabolites were detected using HPLC and LCMS analysis, with anthocyanidins (pelargonidin and cyanidin) being the most abundant phenolic molecules that were measured in all the buckwheat samples. Removing the hull was beneficial for increasing the powder bulk density, whereas the hulled buckwheat samples were more easily rehydrated. The implementation of buckwheat as a staple food crop has enormous potential for the food industry, human nutrition, and diet diversification and could contribute towards meeting the daily recommendation for dietary fiber, essential amino acids, and minerals in Western-style diet countries such as the UK. Full article

Perennial groundcover (PGC) merges scalable soil and water conservation with high-yielding row crops, enhancing ecosystem services of annual grain crop production. However, ineffective groundcover suppression increases competition between the groundcover and row crop, reducing row crop grain yield. The objective of this study was to assess the effectiveness of three Kentucky bluegrass (KBG) groundcover suppression methods each at narrow and wide widths on maize (Zea mays L.) growth and development in evenly spaced PGC, compared to alternating PGC swards and a no-PGC conventional tillage control. Suppression methods for evenly spaced PGC included two different strip tillage implements, completing either shallow or deep soil fracture, for mechanical suppression and a banded sprayer for no-tillage chemical suppression. We measured weekly for maize plant height, phenological stage of development, reflected red:far-red (R:FR) ratio, early vegetative and final plant density, grain and stover yield, yield components of kernel rows ear⁻¹, kernels row⁻¹, kernels ear⁻¹, ear length, kernel weight, grass frequency, and weed community. In 2020, maize grain yield in the alternating PGC swards (11.38 Mg ha⁻¹) was similar to the control (12.78 Mg ha⁻¹) and greater than in the evenly spaced groundcover (9.62 Mg ha⁻¹). Maize grain yield was similar for systems in 2021 (7.41 Mg ha⁻¹), due to drought and high coefficient of variation. Weed community was similar for systems in both years. A maize competition response was observed for both suppression widths across methods. Groundcover dormancy may be needed in conjunction with effective chemical and/or mechanical groundcover suppression to support maize production in PGC. Full article

In 2016–2018, an experiment with Sida hermaphrodita L. Rusby (Virginia fanpetals) called Sida was conducted in the system of random blocks on sandy and sandy loam soil. Each year, the yields of dry aboveground mass and dried mass of roots were determined. Before sowing Sida and after the end of the research, the composition of earthy fractions in the soils was determined. In the stalks and roots of Sida, the percentage content was determined, and the mass of carbon was calculated. When Sida was grown in sandy soil, the average dry mass yield (stalks and roots) in the third year of cultivation (2018), was slightly above 13 t∙ha⁻¹, and in the sandy loam soil it was three times higher (36 t∙ha⁻¹). In the third year of cultivation, the carbon sequestration in the stems and roots exceeded 5 t∙ha⁻¹ (sandy soil), and 15 t∙ha⁻¹ (sandy loam). The carbon content in the stems was 46.25%, and in the roots–42.67%. The results were statistically processed using ANOVA. It was found that the cultivation of Sida caused a percent decrease in the sand fraction, an increase in the floatable (fine) fraction in sandy soil, and an increase in humus content; the opposite changes were noted in the sandy-loam soil. Full article

Mating success of artificially reared males of the olive fruit fly is essential for genetic control techniques for this pest. We studied the mating competition between males from a laboratory-adapted population reared with an artificial diet and wild males emerged from field-infested olives and grown in olives in the laboratory. We maintained virgin wild females or artificially reared females in cages together with virgin wild and artificially reared males and scored the percentages of different males in the mated pairs, mating latency, and mating duration. After mating, we determined the egg production and the size of spermathecae of females mated with different males. Our results indicate that artificially reared males are competitive to the wild males, and they mated in similar percentages with wild and artificially reared females. Mean mating latencies (SE) of wild females that mated with wild and artificially reared males were 69.8 (4.8) min (n = 39) and 114.6 (8.1) (n = 43) min, respectively. No difference was discovered in the mating duration or egg production between females that mated with a wild or artificially reared male. Wild females had higher spermathecae volume when they mated with wild males compared to artificially reared males (two-tailed t-test = −2.079, df = 54, p = 0.0423). Full article

Brassicaceae products have been extensively studied for their biofumigant activity; despite this, few investigate their effect on soil proprieties. This paper aims to describe the effect on soil fertility by adding the seed meal of Brassica carinata at three different doses corresponding to field dose (3 tons/ha), 10 and 100 fold this dose in organic soil. The organic carbon balance was evaluated by analysing the oxidisable, humified and mineralised carbon fractions. Microbial activity was measured by enzymes linked to the carbon, phosphorous and sulphur cycles—β-glucosidase, phosphatase and arylsulphatase, respectively. The amount corresponding to 30 t/ha was the best solution for the mineralised carbon and humic carbon ratio. In contrast, there was a substantial increase in the organic substance’s mineralisation level at the maximum dose, not offset by a relative rise in humification. No repression was observed in the metabolic activity of the microorganisms, their abundance or the main enzymatic activities and, in the conditions tested, a release of only a volatile isothiocyanate occurred, limiting the biofumigant effect. Therefore, these combined factors allow us to assert that the amendment with this type of material at the intermediate dose could positively affect the phosphorus cycle, the soil structure, and fertility. Full article

The man-made cereal triticale was fully resistant to the biotrophic diseases powdery mildew, leaf rust, yellow rust, and stem rust from its introduction in Europe in the mid-1970s until about 1990. In the following years, new races that were able to infect at least some triticale genotypes developed in all four pathogen populations, and resistance breeding came into focus. Here, we analyzed 656 winter triticale cultivars from 12 countries for resistance to these biotrophic diseases and Fusarium head blight (FHB) at up to 8 location-year combinations (environments). FHB ratings were corrected for plant height and heading stage by comparing three statistical methods. Significant (p < 0.001) genetic variances were found for all resistances with moderate to high entry-mean heritabilities. All traits showed a normal distribution, with the exception of stem rust, where the ratings were skewed towards resistance. There were no substantial correlations among the five disease resistances (r = −0.04 to 0.26). However, several genotypes were detected with multi-disease resistance with a disease rating below average for all five diseases simultaneously. In future, such genotypes must be selected primarily to cope with future challenges of less pesticide use and global climate change. Full article

Trichoderma fungi are promising candidates for biocontrol agents and plant growth promoters. Trichoderma atrobrunneum and T. simmonsii were evaluated for the control of soil-borne phytopathogenic fungi, in the present study. Dual culture tests with Rhizoctonia solani and Fusarium oxysporum f. sp. lycopersici were used to conduct in vitro evaluation. In the presence of Trichoderma, phytopathogen’s growth rate was inhibited up to 59.70% for R. solani and 42.57% for F. oxysporum. Greenhouse trials with potted tomato plants demonstrated that Trichoderma caused a significant increase of stem height and fresh stem weight in pathogen-inoculated plants, compared with the negative control (plants artificially inoculated with the phytopathogen only). Except for T. simmonsii, plant growth was not significantly enhanced by a Trichoderma presence in the positive control (healthy plants). The overall performance of the two Trichoderma species studied was equivalent to that of the T. harzianum T22 commercial strain. All the tested species were found to be effective in suppressing colony growth and disease development of the soil borne pathogens in dual cultures and potted plants, indicating that they could be used as biocontrol agents. Our findings are discussed in the context of enhancing endophytic microorganisms’ application in crop production systems. Full article