Distribution pattern of arthropods on the leaf surfaces of Acacia auriculiformis saplings

Acacia auriculiformis A. Cunn. Ex Benth. (Fabaceae), a non-native pioneer species in Brazil with fast growth and rusticity, is used in restoration programs. Our goal was to assess during a 24-month survey the pattern of arthropods (phytophagous insects, bees, spiders, and predator insects) on the leaf surfaces of A. auriculiformis saplings. Fourteen species of phytophagous, two of bees and eleven of predators were most abundant on the adaxial surface. The values of the ecological indexes (abundance, diversity, and species richness) and the rarefaction, and k-dominance curves of phytophagous, bees and arthropod predators were highest on the adaxial leaf surface of A. auriculiformis. The k-dominance and abundance of Aleyrodidae (Hemiptera) (both leaf surfaces), the native stingless bee Tetragonisca angustula Latreille (Hymenoptera: Apidae) (both leaf surfaces) and the ant Brachymyrmex sp. (adaxial surface) and Pheidole sp. (Hymenoptera: Formicidae) (abaxial surface) were the highest between the taxonomic groups of phytophagous, bees, and predators, respectively on A. auriculiformis saplings. The ecological indexes and rarefaction, abundance, and k-dominance curves of phytophagous insects, bees, and predators were highest on the adaxial leaf surface. The preference of phytophagous insects for the adaxial leaf surface is probably due to the lower effort required to move on this surface. Understanding the arthropod preferences between leaf surfaces may help to develop sampling and pest management plans for the most abundant phytophagous insects on A. auriculiformis saplings. Also, knowledge on the preference pattern of bees and predators may be used to favour their conservation.

Arthropod fauna on the abaxial and adaxial surfaces of Acacia mangium (Fabaceae) leaves

Acacia mangium (Willd., 1806) (Fabales: Fabaceae) is a fast growing, rustic, pioneer species, with potential to fix nitrogen, and for programs to recover degraded areas. The objective was to evaluate the distribution and the functional diversity of interactions and the K-dominance of arthropod groups on A. mangium saplings. The number of individuals of eleven species of phytophagous insects, three bee species, and fourteen natural enemy species were highest on the adaxial leaf surface of this plant. Abundance, diversity and species richness of phytophagous insects and natural enemies, and abundance and species richness of pollinators were highest on the adaxial A. mangium leaf surface. The distribution of five species of sap-sucking hemipterans and six of protocooperating ants (Hymenoptera), with positive interaction between these groups, and three bee species (Hymenoptera) were aggregated on leaves of A. mangium saplings. Aethalion reticulatum (L.) (Hemiptera: Aethalionidae) and Bemisia sp. (Hemiptera: Aleyrodidae); Brachymyrmex sp. and Camponotus sp. (Hymenoptera: Formicidae); and Trigona spinipes Fabricius (Hymenoptera: Apidae) were the most dominant phytophagous insects, natural enemies, and pollinators, respectively, on A. mangium leaves. Knowledge of preferred leaf surfaces could help integrated pest management programs.

Kaolin Particle Film Protects Grapevine cv. Cabernet Sauvignon Against Downy Mildew by Forming Particle Film at the Leaf Surface, Directly Acting on Sporangia and Inducing the Defense of the Plant

Downy mildew is a major threat to viticulture, leading to severe yield loss. The use of traditional copper-based fungicides is effective, but has adverse effects on the environment and human health, making it urgent to develop an environmentally friendly disease management program. Multi-functional kaolin particle film (KPF) is promising as an effective and safer treatment strategy, since this material lacks chemically active ingredients. In this study, ability of Kaolin particle film (KPF) pretreatment to protect grapevine leaves from Plasmopara viticola was tested and the mode of action of KPF was analyzed. KPF application reduced the disease severity and the development of intercellular hyphae. Additionally, there was reduced accumulation of H2O2 and malondialdehyde (MDA) with pretreatment. The observation of ultrastructure on the leaf surface showed KPF deposition and stomatal obstruction, indicating that KPF protected plants against disease by preventing the adhesion of pathogens to the leaf surface and blocking invasion through the stomata. KPF pretreatment also activated host defense responses, as evidenced by increased activities of anti-oxidative enzymes [superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT)] and defense-related enzymes [phenylalanine ammonia-lyase (PAL), chitinases, and β-1,3-glucanases], increased phytohormone signals [abscisic acid (ABA), salicylic acid (SA), and jasmonic acid (JA)] and the up-regulation of defense genes related to plant defense. Overall, these results demonstrate that KPF treatment counters grapevine downy mildew by protecting leaves and enhancing plant defense responses.

DESIGN AND TEST OF SELF-PROPELLED STRADDLE-TYPE LYCIUM BARBARUM L. SPRAYING MACHINE

According to the planting agronomy of Lycium barbarum L. in Ningxia, a self-propelled straddle-type sprayer was designed. The aim was to reduce the labor requirements, improve the spraying effect to the middle and lower parts of the canopy, reduce the influence of natural wind on droplet drift, and recycle excess liquid medicine to reduce environmental pollution. Tests showed that the coverage rate of liquid medicine on the leaf surface and back of the leaf peaked at 84.2% and 48.3%, respectively, when spraying pressure was high. Under different spraying distances, the coverage rate of liquid medicine on leaf surface and back of leaf reached 73.3% and 38.3% at the shortest distance. The uniformity of the spray droplet distribution was good, the use error was less than 10%, and the excess liquid was effectively recovered.

Efficiency of soybean photosynthesis as affected by the components of cultivation technology

Purpose. Determine the efficiency of photosynthesis of soybean varieties ‘Ustia’, ‘Kordoba’, ‘Estafeta’ as affected by the use of microfertilizers and growth regulators. Methods. Field, laboratory. Results. The article presents the results of research to study the effectiveness of photosynthesis in the cultivation of different varieties of soybean. It was found that the treatment of plants with microfertilizer Yara Vita Mono Molitrak in the budding phase (0.25 l/ha) + in the flowering phase (0.25 l/ha) in combination with the growth regulator Radostym ensured a leaf area (1000 m2/ha) increase of 7.2 m2/ha in variety ‘Ustia’, 7.6 in ‘Kordoba’ and 5.2 in ‘Estafeta’, compared to control. At the same time, the efficiency of using the growth regulator Biosil against the background of double treatment with the microfertilizer was at the level of the treatments with single treatments with Yara Vita Mono Molitrak in the budding phase (0.25 l/ha) in combination with appropriate growth regulators. Conclusions. It was investigated that the leaf surface area of ‘Ustia’ variety with foliar fertilization using Yara Vita Mono Molitrak microfertilizer in the budding phase (0.25 l/ha) in combination with growth regulators Biosil and Radostym was 38.8 and 39.2 thousand m2/ha. The use of microfertilizers twice in combination with the above-mentioned growth regulators contributed to the increase of leaf area to the level of 38.9 and 39.5 thousand m2/ha, respectively. Similarly, in ‘Kordoba’ soybean variety, the best option was the use of Yara Vita Mono Molitrak in the budding phase (0.25 l/ha) + in the flowering phase (0.25 l/ha) in combination with the growth regulator Radostym, which helped to increase the leaf area to 39.5 thousand m2/ha. Foliar fertilization with microfertilizers combined with the use of growth regulators provides the formation of maximum NPP. Thus, in ‘Ustia’ variety, it was 1.47 and 1.45 g/m2, in ‘Estafeta’ 1.82 and 1.82 g/m2 of dry matter per day.

Formation of photosynthetic parameters of winter wheat crops under foliar fertilization and herbicide application

Purpose. To study agronomic measures for the care of winter wheat: the use of foliar fertilization and protection against weeds with sulfonylureas. Methods. Field and laboratory. Results. It was investigated that the application of Bioforge anti-stress fertilizer did not significantly affect the growth of photosynthetic potential of crops, as the leaf surface area was not significantly different. In addition to the area of the photosynthetic leaf surface, there is a more accurate indicator, that is net productivity of photosynthesis, which can, in our opinion, more accurately show whether the effects of plant protection products against weeds lead to changes in physiological processes in the plant. the mechanism of action of the anti-stress agent is somewhat different. After all, the organization of the photosynthetic apparatus of plants can be such that for a relatively small area of leaves you can get better rates of dry matter accumulation. The best indicators of photosynthetic potential for the use of plant protection products in autumn were identified with the use of such products as Granstar Pro 75, WG, Logran 75, WG, Harmony 75, WG, for introduction into the phenophase BBCH 10–13, and in spring for use in BBCH 27–29 in combination with Bioforge and separately. However, the introduction of PIC 75, WG, to form the best photosynthetic potential of winter wheat crops should be carried out in the phase of BBCH 7–9 in autumn or spring in BBCH 25–26. We also investigated that the use of Bioforge anti-stress fertilizer did not significantly affect the growth of photosynthetic potential of crops. Conclusions. It was determined that the use of the anti-stress agent Bioforge had a positive effect on the condition of plants and their accumulation of dry matter. Accordingly, the best indicators of net productivity of wheat photosynthesis were obtained with the use in autumn of such products as Granstar Pro 75, WG, Logran 75, WG, Harmony 75, WG, for introduction into the phenophase BBCH 10–13, and spring for use in BBCH 27–29 in combination with Bioforge. However, the introduction of PIC 75, WG, to form the best photosynthetic potential of winter wheat crops should be carried out in the phase of BBCH 7–9 in autumn or spring in BBCH 25–26 in combination with Bioforge.

INFLUENCE OF WETTING CONDITIONS OF SANDY SOILS ON THE PRODUCTIVITY OF WINTER RYE

For many years of creating a new breeding material for winter rye in the changing soil and climatic conditions of the Novozybkovskaya Agricultural Management Plant, the influence of precipitation during the growing season on the grain productivity of diploid winter rye has been studied. It has been established that the lack of moisture during ear formation and maximum growth of the leaf surface (May) and excess during grain ripening (July) negatively affects productivity. The new varietal material of diploid winter rye showed resistance to lodging of 5 points, since the plant height averaged 109 cm with a variation from 98 to 126 cm. The number of productive stems at a seeding rate (manual) of 600 thousand grains/ha averaged 10 pieces, varying from 5 to 16 over the years with a dense elastic straw. The spike is 14 cm long with 42 spikelets and the grain weight from an ear is 2.7 g, the grain yield is 700–800 g/m2. With a high number of productive stems, an economically effective seeding rate of 150–170 kg / ha has been established, which ensures production of up to 5–6 t/ha of grain in production crops.

Leaf surface index as an indicator of moisture responsiveness and drought resistance of winter bread wheat samples

The growth and productivity of drought-prone varieties are strongly influenced by the chlorophyll pigment content and the development of plants’ foliage. The current climate changing, characterized by long no-rain periods followed by short intense rainfalls, is forcing plants to adopt different strategies to cope with drought. The purpose of the current study is to estimate the effect of growing conditions on the indicators of the total leaf area, leaf surface index (LSI) of sowing, the concentration of chlorophylls (Chl) in the leaves and the yield of winter wheat, depending on the value of their moisture supply. There have been established that the leaf surface index change and the preservation of chlorophyll pigment in foliage during the vegetation period is closely related to plants’ drought resistance, soil moisture reserve and a genotype. Under conditions of insufficient moisture supply, the maximum values of the leaf surface index in the heading phase were formed by the varieties ‘Krasa Dona’ (5.99 r.u) and ‘Etyud’ (2.49 r.u.). The highest content of chlorophyll pigment, both in the heading phase and in the flowering phase, was identified in the varieties ‘Krasa Dona’ (3.7; 3.0 mg/100 g of raw material), ‘Etyud’ (3.4; 3.2 mg/100 g of raw material) and ‘Volny Don’ (3.2; 3.0 mg/100 g of raw material), respectively. Acording to the value of productivity, the reliably standard variety ‘Don 107’ has exceeded the varieties ‘Etyud’, ‘Krasa Dona’, ‘Asket’, ‘Volny Don’.

NUTRITION OF YOUNG LEMON PLANTS IN THE OPEN FIELD

The article provides scientific data on the study of optimal norms and timing of leaf feeding in the care of young lemon seedlings in the open field. The care of young lemon seedlings in the open field focuses on the rapid growth of branches, enlargement of leaf surface and leaf activity. Due to the additional nutrition of the leaves, the growth and development of young lemon seedlings is accelerated, the leaf surface is cleaned of dust, which has a positive effect on the metabolism of the leaves, the process of respiration and photosynthesis in the leaves. As a result, young lemon seedlings grow well in the short term and are formed as seedlings ready for planting in the main area. KEYWORDS: lemon, seedling, seedling, twig, leaf surface, open area, air temperature, relative humidity, fertilizer, suspension, photosynthesis.