Effect of Colored Shading Nets on the Growth and Water Use Efficiency of Sweet Pepper Grown under Semi-arid Conditions

Colored shading nets have been increasingly studied in semi-arid crop production systems, primarily because of their ability to reduce solar radiation with the attendant reductions in air, plant, and soil temperatures. However, there is a paucity of research concerning the impact of colored shading nets on various crops grown under semi-arid environments, particularly the sweet pepper (Capsicum annum) production system. This study aimed to investigate the effects of three colored shading net treatments (i.e., white, green, and black shading nets with 50% shading intensity and control with unshaded conditions) on the growth and instantaneous water use efficiency (WUE) of sweet pepper. The results showed that all colored shading nets exhibited significantly lower daytime air temperatures and light intensity (22 to 28 °C and 9992 lx, respectively) compared with the control (32 to 37 °C and 24,973 lx, respectively). There were significant differences in sweet pepper growth performance among treatments, including plant height, shoot dry weight, leaf area, leaf chlorophyll content, and vitamin C in ripened fruit. The enhanced photosynthetic rates were observed in sweet pepper plants under the colored shading nets compared with control plants. WUE increased among the colored shading net treatments in the following order: control ≤ white < black < green. Overall, the application of green and black shading nets to sweet pepper production systems under semi-arid environments significantly enhanced plant growth responses and WUE.

Sweet pepper varieties for Western Siberia

Представлены результаты селекционной работы по культуре перца сладкого. Показано влияние основных факторов среды на рост растений перца в условиях резко континентального климата Западной Сибири. Освещены некоторые направления сортовой селекции для необогреваемых теплиц и открытого грунта. Главное направление селекции – создание скороспелых сортов с высокой потенциальной продуктивностью, использование которых позволит получать не только гарантированный урожай, но и успешно вести семеноводство. Экспериментальные данные получены в условиях Западной Сибири (г. Барнаул, Алтайский край) при выращивании перца в открытом грунте и необогреваемых пленочных теплицах (весенне-летний культурооборот) на ЗСООС – филиале ФГБНУ ФНЦО. Селекционную работу вели с 2000 года и по настоящее время. Оценку селекционного материала проводили в 2015–2021 годах. Материалом для исследований служили коллекционные, селекционные образцы перца различного генетического и эколого-географического происхождения, а также созданные сорта. Представленные сорта перца пластичны, обладают комплексом хозяйственно ценных признаков: высокой урожайностью, хорошим качеством продукции, устойчивостью к стрессовым факторам и основным болезням. Наиболее востребована группа сортов с конусовидными и пирамидальными плодами (Сибирский князь, Подарок лета, Кавалер, Солнечная улыбка, Золотая пирамида), урожайность которых 4–6 кг/м2 в теплице, в открытом грунте – 26–42 т/га, содержание витамина С – 114–248 мг%, пригодные для салатов, цельноплодного консервирования, замораживания и фарширования. Сорта Солнечная улыбка и Золотая пирамида с плодами оранжевой и желтой окраски в биологической спелости незаменимы при украшении блюд. Крупноплодные сорта с плодами призмовидно-кубовидной формы различной окраски в технической спелости: Викинг (темно-зеленая) и Вальс (светло-зеленая) востребованы в течение всего сезона, особенно в период заготовок впрок. Урожайность этой группы сортов в теплице – 4–7 кг/м2, в открытом грунте – 26–39 т/га, содержание витамина С – 120–191 мг%. Сорта перспективны для выращивания в Сибири, способны удовлетворить высокие требования овощеводов и потребителей. The results of breeding work on the culture of sweet pepper are presented. The influence of the main environmental factors on the growth of pepper plants in the sharply continental climate of Western Siberia is shown. Some directions of varietal selection for unheated greenhouses and open ground are highlighted. The main direction of breeding is the creation of precocious varieties with high potential productivity, the use of which will allow not only to obtain a guaranteed harvest, but also to successfully conduct seed production. Experimental data were obtained in the conditions of Western Siberia (Barnaul, Altai Krai) when growing pepper in the open ground and unheated film greenhouses (spring-summer cultural turnover) at the WSVES – branch of the FSBSI FSVC. Breeding work was carried out from 2000 to the present. The selection material was evaluated in 2015–2021. The materials for research were collectible, breeding samples of pepper of various genetic and ecological-geographical origin, as well as created varieties. The presented varieties of pepper are plastic, have a complex of economically valuable characteristics: high yield, good product quality, resistance to stress factors and major diseases. The most popular group of varieties with cone-shaped and pyramidal fruits (Sibirskii knyaz», Podarok leta, Kavaler, Solnechnaya ulybka, Zolotaya piramida), the yield of which is 4–6 kg/m2 in a greenhouse, in the open ground – 26–42 t/ha, vitamin C content – 114–248 mg%, suitable for salads, whole-fruit canning, freezing and stuffing. Varieties Solnechnaya ulybka and Zolotaya piramida with orange and yellow fruits in biological ripeness are indispensable for decorating dishes. Large-fruited varieties with prismatic-cuboid fruits of various colors in technical ripeness: Viking (dark green) and Val's (light green) are in demand throughout the season, especially during the harvesting period for the future. The yield of this group of varieties is 4–7 kg/m2 in a greenhouse, in the open ground – 26–39 t/ha, vitamin C content 120–191 mg%. The varieties are promising for cultivation in Siberia, able to meet the high demands of vegetable growers and consumers.

Molecular characterization and in vitro control measures of fruit rot disease of Sweet pepper

Fruit rot disease of sweet pepper is one of the main fungal diseases causing huge economic losses to the grower. An experiment was conducted to find out the fungal pathogen associated with fruit rot disease of sweet pepper, obtained from experimental fields of Jahangirnagar University, Bangladesh. Fruit rot disease-causing fungus was isolated from infected fruits and identified using morphological characterization based on colony features, mycelia, conidia as well as molecular characterization based on internal transcribe spacer (ITS) region of the fungus. ITS sequence of our studied fungus MH368146.1 was genetically 99-100% similar to sequences of Fusarium solani in NCBI database. Typical fruit rot symptoms were reproduced by artificial inoculations of the isolated fungus. The mycelial growth of this fungus was evaluated on ten different solid culture media i.e., Potato Dextrose Agar, Yeast Extract Agar, Honey Peptone Agar, Hansen’s Medium, Sabouraud’s Glucose Agar, Kauffman’s Agar, Potato Sucrose Agar, Richard’s Agar and Carrot Agar. Fungus grew well on all tested solid culture media. Several bio-control agents and two commercial fungicides were evaluated against isolated fungus under in vitro condition, in which the highest percent inhibition of radial growth of the fungus was determined as 64.75% due to Trichoderma reesei isolate 2, and 60.63% by Tilt 250 EC (500 ppm) at 7 days post-incubation. Therefore, T. reesei was found as the most suitable to control the growth of F. solani under laboratory conditions. However, further pot and field trials needed to be confirmed the bio-control potential of it. Int. J. Agril. Res. Innov. Tech. 11(2): 108-116, Dec 2021

Eliciting Plant Defenses Through Herbivore-Induced Plant Volatiles’ Exposure in Sweet Peppers

Insect herbivory activates plant defense mechanisms and releases a blend of herbivore-induced plant volatiles (HIPVs). These volatile compounds may be involved in plant-plant communication and induce defense response in undamaged plants. In this work, we investigated whether the exposure of sweet pepper plants to HIPVs [(Z)-3-hexenol, (Z)-3-hexenyl acetate, (Z)-3-hexenyl propanoate, (Z)-3-hexenyl butanoate, hexyl butanoate, methyl salicylate and methyl jasmonate] activates the sweet pepper immune defense system. For this, healthy sweet pepper plants were individually exposed to the each of the above mentioned HIPVs over 48 h. The expression of jasmonic acid and salicylic acid related genes was quantified. Here, we show that all the tested volatiles induced plant defenses by upregulating the jasmonic acid and salicylic acid signaling pathway. Additionally, the response of Frankliniella occidentalis, a key sweet pepper pest, and Orius laevigatus, the main natural enemy of F. occidentalis, to HIPV-exposed sweet pepper plants were studied in a Y-tube olfactometer. Only plants exposed to (Z)-3-hexenyl propanoate and methyl salicylate repelled F. occidentalis whereas O. laevigatus showed a strong preference to plants exposed to (Z)-3-hexenol, (Z)-3-hexenyl propanoate, (Z)-3-hexenyl butanoate, methyl salicylate and methyl jasmonate. Our results show that HIPVs act as elicitors to sweet pepper plant defenses by enhancing defensive signaling pathways. We anticipate our results to be a starting point for integrating HIPVs-based approaches in sweet pepper pest management systems which may provide a sustainable strategy to manage insect pests in horticultural plants.

Influence of basic treatment of irrigated land on Fertility indicators and harvest formation of sweet pepper

The purpose of the research was to establish the most rational soil cultivation system for irrigated conditions, contributing to the preservation of ecological balance and increasing the profitability of pepper production. Experimental studies were carried out on meadow-chestnut soils of the plain zone of the Republic of Dagestan in 2017-2019. in a two-factor experiment to determine the most effective combination of soil cultivation and irrigation regime. The paper presents the results of the influence of plowing and disc cultivation on the water-physical properties of the soil and its biological activity, as well as on the yield of sweet pepper under drip irrigation. The results of three-year research have established that, under irrigation conditions, the most effective method of basic soil cultivation is moldboard soil cultivation to a depth of 0.23 ... 0.25 m, which contributed to the improvement of soil density, its permeability, structural state and increased biological activity in the treated layer. On plowing, the yield of sweet pepper fruits was obtained at the level of 6.23 t/ha. The use of disc processing by 0.10 ... 0.12 m leads to a deterioration of agrophysical indicators of fertility, phytosanitary state of irrigated fields by 1.7 ... 2.2 times, a decrease in yield by 5.1 ... 9.6% and profitability of pepper fruit production by 25.3 ... 31.0%.