Subtropical Conditions Research Articles

Evaluation of Cape Gooseberry Varieties for Growth and Bioactive Compounds Under Subtropical Conditions of Northwestern India

Evaluation of Cape Gooseberry Varieties for Growth and Bioactive Compounds Under Subtropical Conditions of Northwestern India

Viability of an Open-Loop Heat Pump Drying System in South African Climatic Conditions

Drying agricultural produce consumes a considerable amount of energy. As an energy-efficient system, a heat pump can improve the energy efficiency of the drying process and hence reduce the energy consumption, especially in South Africa, where both sub-tropical and temperate weather conditions dominate. The objective of this research is to experimentally investigate the impacts of weather conditions on the operational conditions and thermal performance of an open-loop air-source heat pump drying system. The experimental investigation was conducted in a climate chamber where the climate conditions were simulated from −10 °C to 20 °C with an interval of 10 °C for the typical temperature range of the harvesting season in South Africa. The findings indicate that ambient temperatures have a significant impact on both the operating conditions and thermal performance of an open-loop heat pump system; the change in ambient temperatures from −10 °C to 20 °C leads to a 141.6% improvement in the suction pressure, a 214.2% increase in the discharge pressure, and 30.1% increase in the compression ratio, as well as a consequent increase of 130.6% in the refrigerant mass flow rate (from 0.0067 to 0.0155 kg/s), resulting in a corresponding increase in the coefficient of performance (COP) of the heat pump drying system by about 42.1%. Therefore, this study suggests that, while using an open-loop air-source heat pump drying system utilising R134a refrigerant is feasible in South Africa, it may be practically limited to regions with warm climates or during warmer seasons.

Prevalence of STEC virulence markers and Salmonella as a function of abiotic factors in agricultural water in the southeastern United States.

Fresh produce can be contaminated by enteric pathogens throughout crop production, including through contact with contaminated agricultural water. The most common outbreaks and recalls in fresh produce are due to contamination by Salmonella enterica and Shiga toxin-producing E. coli (STEC). Thus, the objectives of this study were to investigate the prevalence of markers for STEC (wzy, hly, fliC, eaeA, rfbE, stx-I, stx-II) and Salmonella (invA) in surface water sources (n = 8) from produce farms in Southwest Georgia and to determine correlations among the prevalence of virulence markers for STEC, water nutrient profile, and environmental factors. Water samples (500 mL) from eight irrigation ponds were collected from February to December 2021 (n = 88). Polymerase chain reaction (PCR) was used to screen for Salmonella and STEC genes, and Salmonella samples were confirmed by culture-based methods. Positive samples for Salmonella were further serotyped. Particularly, Salmonella was detected in 6/88 (6.81%) water samples from all ponds, and the following 4 serotypes were detected: Saintpaul 3/6 (50%), Montevideo 1/6 (16.66%), Mississippi 1/6 (16.66%), and Bareilly 1/6 (16.66%). Salmonella isolates were only found in the summer months (May-Aug.). The most prevalent STEC genes were hly 77/88 (87.50%) and stx-I 75/88 (85.22%), followed by fliC 54/88 (61.63%), stx-II 41/88 (46.59%), rfbE 31/88 (35.22%), and eaeA 28/88 (31.81%). The wzy gene was not detected in any of the samples. Based on a logistic regression analysis, the odds of codetection for STEC virulence markers (stx-I, stx-II, and eaeA) were negatively correlated with calcium and relative humidity (p < 0.05). A conditional forest analysis was performed to assess predictive performance (AUC = 0.921), and the top predictors included humidity, nitrate, calcium, and solar radiation. Overall, information from this research adds to a growing body of knowledge regarding the risk that surface water sources pose to produce grown in subtropical environmental conditions and emphasizes the importance of understanding the use of abiotic factors as a holistic approach to understanding the microbial quality of water.

Productivity and profitability of chickpea as influenced by varying levels of phosphorus and bio-fertilizers under sub-tropical conditions of Madhya Pradesh

In the present study, the influence of phosphorus and bio-fertilizers was investigated on the productivity and profitability of summer black gram. The experimental study revealed that among the phosphorus levels, the application of 50 kg P ha-1 recorded significantly the high seed (1108 Kg ha-1) and stover (2616 Kg ha-1) yield. However, among the bio-fertilizers, t h e application of phosphate solubilizing bacteria + Rhizobium resulted in the highest seed (1116 Kg ha-1) and stover yield of chickpea (2655 Kg ha-1). Application of 50 kg ha-1 phosphorus and combined treatment of phosphate solubilizing bacteria + Rhizobium incurred the highest cost of cultivation (₹ 30,421 ha-1), highest gross return (₹ 1,00,015 ha-1), net return (₹ 69,594 ha-1) and benefit-cost ratio (₹ 2.29). It can be concluded that the application of 50 kg ha-1 phosphorus and treatment of phosphate solubilizing bacteria+ Rhizobium in chickpea cultivation may be profitable.

Effect of phosphorus levels and bio-fertilizers on nutrient uptake, quality and yield of chickpea under sub-tropical conditions of Madhya Pradesh

In the present investigation, the effect of phosphorus (P) levels and biofertilizers on nutrient uptake, quality and yield of chickpea was studied over two years during Rabi 2021–22 and 2022–23. The study revealed significantly higher uptake of N, P and potassium (K) by seed and stover, higher protein content, grain, and stover yield on the application of 50 kg ha-1 P. Similarly application of 50 kg ha-1 P along with bio-fertilizers (PSB + Rhizobium) also showed higher N, P and K uptake by seed and stover, higher protein content and protein yield, grain and stover yield and this combination was identified the most promising treatment for enhancing chickpea yield.

Morpho-physiological studies of sandalwood-host interaction under individual and interactive water and salt stress.

To find out the possibilities of growing white sandalwood in sub-tropical regions of India where farmers facing the problem of water deficit and salinity stress, a RBD experiment was conducted. Sandalwood grown alone and with five selected hosts (Alternanthera sp., Neem, Shisham, Dek and Agarwood) on the basis of prior study under water deficit, salinity stress and combined water deficit and salinity stress. Sandalwood plants were harvested after 180days of imposing stress treatments. Morphological traits (plant height, collar diameter, shoot fresh and dry biomass) showed significant reduction under water deficit and salinity stress, which were further aggravated under combined water deficit and salinity stress. Studied plant water traits, ionic balance and gas exchange attributes were also reduced by these stresses. While among studied host, Shisham and Dek identified as the best host species under water deficit, salinity and interactive stress by maintaining ion homeostasis, osmotic adjustments and plant water regulation. Results depicted that sandalwood plants cultivated alone were not able to survive under salinity and combined stress conditions and showed poor growth under water deficit and control conditions. Different indices were also calculated based on morpho-physiological and ionic traits and also indicated that sandalwood grown with Dalbergia sissoo and Melia dubia showed higher drought, salt and stress tolerance potential, which made sandalwood adaptable under these stresses. Therefore, the present study signifies the importance of host especially D. sissoo and M. dubia which might be excellent long-term host species for sandalwood cultivation under sub-tropical conditions to thrive under changing environments.

Unveiling the phenology and associated floral regulatory pathways of Humulus lupulus L. in subtropical conditions.

The hop phenological cycle was described in subtropical condition of Brazil showing that flowering can happen at any time of year and this was related to developmental molecular pathways. Hops are traditionally produced in temperate regions, as it was believed that vernalization was necessary for flowering. Nevertheless, recent studies have revealed the potential for hops to flower in tropical and subtropical climates. In this work, we observed that hops in the subtropical climate of Minas Gerais, Brazil grow and flower multiple times throughout the year, independently of the season, contrasting with what happens in temperate regions. This could be due to the photoperiod consistently being inductive, with daylight hours below the described threshold (16.5h critical). We observed that when the plants reached 7-9 nodes, the leaves began to transition from heart-shaped to trilobed-shaped, which could be indicative of the juvenile to adult transition. This could be related to the fact that the 5th node (in plants with 10 nodes) had the highest expression of miR156, while two miR172s increased in the 20th node (in plants with 25 nodes). Hop flowers appeared later, in the 25th or 28th nodes, and the expression of HlFT3 and HlFT5 was upregulated in plants between 15 and 20 nodes, while the expression of HlTFL3 was upregulated in plants with 20 nodes. These results indicate the role of axillary meristem age in regulating this process and suggest that the florigenic signal should be maintained until the hop plants bloom. In addition, it is possible that the expression of TFL is not sufficient to inhibit flowering in these conditions and promote branching. These findings suggest that the reproductive transition in hop under inductive photoperiodic conditions could occur in plants between 15 and 20 nodes. Our study sheds light on the intricate molecular mechanisms underlying hop floral development, paving the way for potential advancements in hop production on a global scale.

A middle Miocene to Quaternary sedimentary and palaeoenvironmental record from the western continental shelf of South Africa

The sedimentary record of the western South African continental shelf is condensed compared to the continental slope and contains erosional unconformities, owing to periods of non-deposition, eustatic sea-level fluctuations, episodic uplift and intensified continental aridity. Despite this, the sedimentary record of the continental shelf provides important information on the depositional history and palaeoenvironmental evolution of the region. A core retrieved from the western shelf of South Africa was analysed for its sedimentary composition, lithological variation, foraminiferal content and its relation to the palaeoenvironment of the region. Four depositional facies were identified along the core, namely quartzitic sand, sandy mud, and glauco-phosphatic sand and a glauco-phosphatic gravel. The basal facies consisting of quartzitic sand is interpreted to have been deposited between 15.90 and 14.60 Ma, corresponding to the timing of the Mid-Miocene Climatic Optimum (MMCO). The highly quartzitic nature of the sediments indicate a high terrestrial influence from fluvial sources. The overlying sandy mud facies was deposited between 14.60 and 13.90 Ma based on planktic foraminiferal biostratigraphy. Foraminiferal analyses of these two facies that were deposited in the Langhian stage of the middle Miocene point to subtropical sea surface conditions and mesotrophic benthic environments. Sea level was noticeably higher during the MMCO and part of the cooling period following the MMCO. An erosional surface that spans 10.77 Myr, equal to the late Miocene (13.90 Ma) to early Pliocene (3.13 Ma), marks the boundary between the two Langhian facies and the overlying two Pleistocene facies, consisting of coarser grained glauco-phosphatic gravelly sand units. The Pleistocene environment on the shelf is interpreted to contrast with the Langhian environment, where cooler, shallower conditions and a more eutrophic benthic environment was prevalent, during a time that Benguela upwelling intensified with higher frequency and higher amplitude sea level fluctuations. Palaeobathymetric interpretations indicate that middle Miocene sea-level in the region were up to 77 m higher than present day and 101 m lower in the Pleistocene, in-line with previous global studies. Glauco-phosphatic content that increase up-core also marks the shallowing of the environment under high productivity conditions.

Factors influencing pregnancy rate and loss after laparoscopic artificial insemination with frozen-thawed semen in Lohi sheep under sub-tropical conditions.

This study evaluates factors influencing pregnancy rates per artificial insemination (P/AI) and pregnancy loss in Lohi ewes undergoing laparoscopic AI with frozen-thawed semen under sub-tropical conditions. Data from three experiments comprising ewes (n = 358) of mixed parity (nulliparous; NP and parous; P), various body condition score (BCS) and assigned to long-term (LTP, 11 days) and short-term (STP, 5 days) oestrus synchronization regimen across high breeding season (HBS) and low breeding season (LBS) were analysed. Laparoscopic insemination was conducted 54 h post-sponge removal. Pregnancy diagnosis and loss were evaluated on days 35 and 90 post-insemination via ultrasonography. Results showed parity significantly influenced P/AI, with nulliparous ewes achieving higher pregnancy ratios than parous ewes (p = .001). BCS significantly influenced P/AI (p < .05), with a quadratic relationship observed between BCS and season (BCS*BCS*Season; p = .07). Progestin treatment did not significantly influence the ratio of pregnant ewes (p = .07). Pregnancy losses were significantly higher during LBS than HBS (p < .05), irrespective of progestin treatment. In conclusion, parity and BCS significantly influenced P/AI, with BCS demonstrating a quadratic association with season. Ewes bred during LBS experienced higher pregnancy losses than HBS, irrespective of progestin treatment.

Mitigating Fruit Cracking and Premature Dropping in Bael (Aegle marmelos) cv. NB-9 under Subtropical Conditions: Evaluating the Effects of Bio-formulations and Boric Acid

The present investigation entitled “Mitigating Fruit Cracking and Premature Dropping in Bael (Aegle marmelos) cv. NB-9 under Subtropical Conditions: Evaluating the Effects of Bio-formulations and Boric Acid” was carried out during the year 2022-2023 at Main Experimental Station, Department of Fruit Science, College of Horticulture &amp; Forestry, A.N.D.U.A.&amp;T., Narendra Nagar (Kumarganj), Ayodhya, Uttar Pradesh, India (Lat 26.540849° Long 81.830421°). Application of various bio-formulations and boric acid with eco-friendly materials to study the various vegetative properties, cracking, fruit drop and effect on the vegetative growth of fruit. The experiment was laid down in randomized block design (RBD) with (12) treatments and (03) replications. The experiment consists of 12 treatments including control, T1 (Control), T2 (FYM 50 Kg), T3 (FYM 100 Kg), T4 (Boric acid 200g), T5 (Boric acid 400g), T6 (Biofertilizer 250g/plant [100g Azotobacter + 100g Biovita + 50g PSB]), T7 (FYM 50Kg + Boric acid 200g), T8 (FYM 50Kg + Boric acid 400g), T9 (FYM 50Kg +Biofertilizer 250g/plant [100g Azotobacter + 100g Biovita + 50g PSB]), T10 (FYM 100Kg + Boric acid 200g), T11 (FYM 100 Kg + Boric acid 400g) and T12 (FYM 100Kg +Biofertilizer 250g/plant [100g Azotobacter + 100g Biovita + 50g PSB]) was used for this study. The results revealed that treatment T7 outperformed the rest with minimum fruit cracking (1.53%), fruit drop (76.20%), the maximum number of flowers per plant (171.19), day-to-flowering (31.38) and yield (181.69 q/ha) was most effective in a vegetative quality and yield point of view. Thus, the treatment combination T7 is therefore recommended for application to Bael trees in subtropical conditions to obtain high yields with better quality fruits.

Performance, blood and antioxidant status in dual-purpose laying hens supplemented with aqueous extract of Christ's thorn jujube (Ziziphus spina-christi L.) leaves as phytogenic agent in subtropical conditions.

The potential of aqueous extract of Christ's thorn jujube (Ziziphus spina-christi) leaves (SLAE) to reduce the negative impacts of heat stress on production performance and physiological traits was investigated in dual-purpose layers under subtropical farming. A total of 200, 25-week-old laying hens (Inshas strain) were randomly assigned to four dietary treatments including SLAE at 0, 2.5, 5.0, and 7.5 mL/kg, respectively. The average temperature-humidity index value was 26.69 during the experimental period. The SLAE contained saponin (0.045%), total flavonoid content of 17.9 mg of quercetin equivalent/ 100 g and overall antioxidant capacity concentration of 17.9 mg of ascorbic acid equivalent/100 g. The maximum final body weight (BW), BW gain, egg weight, number, and mass occurred at the level of SLAE7.5 inclusion. The egg quality was significantly higher in SLAE groups than in control, and overall, SLAE7.5 had the most favorable influence at 28 and 32 weeks. Liver and kidney function, as well as lipids profile, improved significantly by SLAE inclusion; the lowest concentrations of these parameters were in SLAE7.5 hens. Treatment with SLAE7.5 increased total antioxidant capacity and endogenous antioxidant enzymes compared to control, whereas no effect on superoxide dismutase was noticed. The addition of SLAE at 7.5 mL/kg diet improved egg laying performance and quality, metabolic profiles, and antioxidant status during hyperthermia conditions.

Ecological dynamics of Arbuscular Mycorrhizal Fungi in wetland and aerobic rice ecosystem under subtropical humid climatic conditions in Eastern India

Ecological dynamics of Arbuscular Mycorrhizal Fungi in wetland and aerobic rice ecosystem under subtropical humid climatic conditions in Eastern India

Age and environmental conditions for the formation of the Pannonian mega-yardang system

The Pannonian mega-yardang system is the northernmost mega-yardang field in Europe, exerting a profound influence on the relief and surface hydrographic structure of Western Hungary. Despite its significance, the precise timing and climatic conditions under which this mega-yardang system formed remain elusive. The geological setting was studied, the former humidity and biome patterns were modelled, the climatically analogous regions of the past climates of the region were identified, and the Köppen Aridity Indices of the region were compared to the aridity values of other yardang fields from five continents in the last 3.3 mys. The geological structure of the yardangs suggests an origin post-dating the Tortonian period but preceding the mid-Pleistocene era. In the Zanclean and in the warmer periods of the Piacenzian, the studied region had humid subtropical climatic conditions that were not suitable for the formation of large-scale aeolian landforms. Similarly, in the Quaternary period, the climate varied between boreal and humid continental, which was not conducive to the formation of mega-yardang fields. Cold semi-arid climatic conditions only existed in the mid-Pliocene cold period and perhaps at the transition of the Pliocene to the Pleistocene. This paleoclimatic hypothesis is in accordance with the Pliocene fossil record of the region, which contains the remains of such arid habitat-dwelling fauna elements as camelids and struthionids. The comparison of the development of Köppen Aridity Indices among yardangs in other territories also suggests that the Pannonian mega-yardang system may have formed around the transition of the Neogene to the Quaternary epochs.Graphical abstract

Pruning techniques affect flowering, fruiting, yield and fruit biochemical traits in guava under transitory sub-tropical conditions

Production of quality fruits in the dry and low humid October–May period has been a challenge in the tropics and sub-tropics having wide weather fluctuations throughout the year. Henceforth, the research aimed at investigating the seasonal variations in vegetative developments as well as flowering, fruiting, yield, and fruit quality of guava emphasizing the off-seasonality by pruning 0 cm (control), 15 cm, 30 cm, and 45 cm from shoot-tip, once a year at spring (early March), monsoon (early June) and autumn (early September) under such atmospheric implications. Yearly and quarterly documentation at wet (June–August and September–November) and dry (December–February and March–May) seasons revealed that pruning in spring and autumn exhibited statistical parity for higher yearly yield of 31.71 kg and 31.58 kg plant−1, respectively. Moreover, spring pruning had maximum yield in the wet season (23.94 kg plant−1), while autumn pruning governed the dry season production (18.11 kg plant−1) having a notable wet period yield (13.47 kg plant−1). Considering the yearly and quarterly in March–May and December–February harvests, autumn pruning exhibited statistical supremacy for total soluble solids, titratable acidity, total sugar, vitamin C, and specific gravity. However, pruning time didn't influence the fruit physiochemical traits at the June–August and September–November quarters producing fruits of inferior quality compared to those of March–May and December–February harvests. On the other hand, pruning lengths of 30 cm and 45 cm demonstrated statistical consistency for auspicious vegetative, reproductive and fruit biochemical properties. Meanwhile, 30 cm pruning produced maximum number of flowers (224.71 plant−1) and fruits (155.89 plant−1), consequently the highest yield (38.38 kg plant−1). Treatment interactions too ascertained that off-season production of superior quality guava can be enhanced by 30 cm shoot-tip pruning in autumn without compromising the year-round harvests.

The effect of additives on the biodegradation of polyhydroxyalkanoate (PHA) in marine field trials

The persistence of conventional fossil fuel-derived plastics in marine ecosystems has raised significant environmental concerns. Biodegradable plastics are being explored as an alternative. This study investigates the biodegradation behaviour in two marine environments of melt-extruded sheets of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) bioplastic as well as blends of PHBV with a non-toxic plasticiser (triethyl citrate, TEC) and composites of PHBV with wood flour. Samples were submerged for up to 35 weeks in two subtropical marine conditions: on the sandy seabed in the sublittoral benthic zone and the sandy seabed of an open air mesocosm with pumped seawater. Rates of biodegradation, lag times and times to 95 % mass loss (T95) were determined through mass loss data and Gompertz modelling. Mechanisms of biodegradation were studied through changes in molecular weight, mechanical properties and surface features. Results reveal a rapid biodegradation rate for all PHBV samples, demonstrating a range of specific biodegradation rates relative to exposed surface area of 0.03 ± 0.01 to 0.09 ± 0.04 mg.d−1.cm−2. This rapid rate of biodegradation meant that the subtle variations in biodegradation mechanisms across different sample thicknesses and additive compositions had little effect on overall lifetimes, with the T95 for most samples being around 250–350 days, regardless of site, highlighting the robust biodegradability of PHBV in seawater. It was only the PHBV-wood flour composite that showed faster biodegradation, and that was only in the exposed ocean site. The mesocosm site was otherwise shown to be a good model for the open ocean, with very comparable biodegradation rates and changes in mechanical properties over time.

Arbuscular Mycorrhizal Fungi, Ascophyllum nodosum, Trichoderma harzianum, and Their Combinations Influence the Phyllochron, Phenology, and Fruit Quality of Strawberry Plants

One biostrategy to boost the sustainability of strawberry cultivation is the application of biostimulants to the growing substrate. Here, we investigated whether the use of biostimulants and their combinations affects the strawberry plants’ phyllochron, phenology, and fruit quality. We tested the absence (control) and presence of biostimulants (arbuscular mycorrhizal fungi (AMF), Ascophyllum nodosum (AN), Trichoderma harzianum (TH), AMF + AN, AMF + TH, AN + TH, and AMF + AN + TH). The experimental design used was in completely randomized blocks (four replications). AMF was represented by a multi-species on-farm inoculant; A. nodosum was represented by the commercial product Acadian®; and T. harzianum was represented by the commercial product Trichodermil®. The leaf emission rate, the occurrence and duration of phenological stages, and fruit quality were assessed. The greatest precocity in terms of harvesting the first fruit was observed in plants grown with AMF + TH, which also had the lowest phyllochron (77.52 °C day·leaf−1). Those treated only with AMF were the latest (144.93 °C day·leaf−1). More flavorful fruits were produced by plants grown with AMF + TH. Plants inoculated with the AMF community, whether or not associated with A. nodosum and T. harzianum, had more than 94% mycorrhizal colonization. We conclude that AMF, A. nodosum, T. harzianum, and their combinations influence the phenology, phyllochron, and fruit quality of strawberry plants. In the growing conditions of the Brazilian subtropics, the AMF and T. harzianum combination shortens the strawberry cycle, from transplanting the daughter plants to harvesting the first fruit, and improves the fruit flavor.

Present Status of Viral Diseases of Grapevine (&lt;i&gt;Vitis Vinifera&lt;/i&gt; L.) and their Management Strategies in India

Grapevine is an important fruit crop cultivated in temperate, subtropical and tropical conditions in India. The maximum share in area, production, and productivity of grapes is governed by four states viz. Maharashtra, Karnataka, Tamil Nadu and Andhra Pradesh. The sudden and drastic changes in climatic conditions and the emergence of diseases have made grapevine cultivation more challenging. Fungal and bacterial diseases are the major constraints in the grapevine production. Besides, some viral diseases like Grapevine Leafroll Disease (GLD) and Rupestris Stem Pitting Associated Diseases (RSPD) are reported in Indian vineyards. Although the presence of Grapevine Leafroll-Associated Viruses (GLRaVs) viz., GLRaV-1, GLRaV-3, and GLRaV-4 are known the impact on yield and quality of the grapes is not yet studied. Similarly, the Rupestris Stem Pitting Associated Virus (RSPaV) is known to infect the Indian vineyards of different locations but a complete understanding of their overall impact on vineyards is lacking. Therefore, it is presumed that fewer or no losses occur due to GLD and RSPD diseases. There is a strong need for hours to study the impact of known viruses on physiological and yield contributing parameters. In addition to this, robust, rapid and reliable diagnostic techniques are required for the detection of known and unknown viruses. The presence of new and emerging viruses in the Indian vineyards cannot be overlooked. Further, for the management of the viruses and avoiding their spread, the availability of Disease-Free Quality Planting Material (DFQPM) is a prerequisite. To produce DFQPM, various tissue culture techniques need to be standardized for the elimination of the virus/es from the diseased vines. The Tissue Culture-Raised Quality Planting Material (TCQPM) needs to be further tested for genetic purity (true-to-type) and virus indexing to confirm DFQPM. By considering the importance of DFQPM, recently, the National Horticulture Board (NHB), Govt. of India in association with the Asian Development Bank (ADB) has initiated a National Mission on Clean Plant Programme. The implementation of this initiative is more challenging and expected to open different avenues of research and development in the production of DFQPM for the growers. This is an important and timely beginning of the production of DFQPM.

Deciphering Winter Sprouting Potential of Erianthus procerus Derived Sugarcane Hybrids under Subtropical Climates.

Winter sprouting potential and red rot resistance are two key parameters for successful sugarcane breeding in the subtropics. However, the cultivated sugarcane hybrids had a narrow genetic base; hence, the present study was planned to evaluate the Erianthus procerus genome introgressed Saccharum hybrids for their ratooning potential under subtropical climates and red rot tolerance under tropical and subtropical climates. A set of 15 Erianthus procerus derived hybrids confirmed through the 5S rDNA marker, along with five check varieties, were evaluated for agro-morphological, quality, and physiological traits for two years (2018-2019 and 2019-2020) and winter sprouting potential for three years (2018-2019, 2019-2020, and 2020-2021). The experimental material was also tested against the most prevalent isolates of the red rot pathogen in tropical (Cf671 and Cf671 + Cf9401) and subtropical regions (Cf08 and Cf09). The E. procerus hybrid GU 12-19 had the highest winter sprouting potential, with a winter sprouting index (WSI) of 10.6, followed by GU 12-22 with a WSI of 8.5. The other top-performing hybrids were as follows: GU 12-21 and GU 12-29 with a WSI of 7.2 and 6.9, respectively. A set of nine E. procerus-derived hybrids, i.e., GU04 (28) EO-2, GU12-19, GU12-21, GU12-22, GU12-23, GU12-26, GU12-27, GU12-30, and GU12-31, were resistant to the most prevalent isolates of red rot in both tropical and subtropical conditions. The association analysis revealed significant correlations between the various traits, particularly the fibre content, with a maximum number of associations, which indicates its multifaceted impact on sugarcane characteristics. Principal component analysis (PCA) summarised the data, explaining 57.6% of the total variation for the measured traits and genotypes, providing valuable insights into the performance and characteristics of the Erianthus procerus derived hybrids under subtropical climates. The anthocyanin content of Erianthus procerus hybrids was better than the check varieties, ranging from 0.123 to 0.179 (2018-2019) and 0.111 to 0.172 (2019-2020); anthocyanin plays a vital role in mitigating cold injury, acting as an antioxidant in cool weather conditions, particularly in sugarcane. Seven hybrids recorded a more than 22% fibre threshold, indicating their industrial potential. These hybrids could serve as potential donors for cold tolerance and a high ratooning ability, along with red rot resistance, under subtropical climates.

Loss of nutrients from meadow-brown soils during irrigation of apple trees in the conditions of the dry subtropics of Azerbaijan

The article presents the results of studies on the effect of water consumption, depending on the length (96, 144 and 192) meters of irrigation furrow with a slope of relief tg = 0.021 on the leaching of nitrogen, phosphorus and humus from irrigated soils of the dry subtropics of Azerbaijan under apple trees. Under conditions of leaching of nutrients, the effect of mineral and organic fertilizer systems on apple yields has also been studied. With a 96-meter furrow and a water consumption of 0.2 l/sec, the content of leached nutrients (N, P) and gross humus with soil was 0.01 % nitrogen and phosphorus, 0.02 % gross humus. Increase in water consumption from 0.2 l/sec. up to 0.4 l/sec. It has a negative effect on the leaching of humus, nitrogen and phosphorus from the soil. With a water consumption of 0.4 l/sec, these indicators increased markedly by 0.01 % for humus, nitrogen and phosphorus. Along the length of the irrigation furrow in both water consumption rates, the leaching of nutrients and humus from the soil increases. It was found that with an increase in the length of the furrow to 192 meters at a water consumption of 0.4 l/sec, the leaching was greater than the 96-meter furrow in humus by 0.22 %, nitrogen by 0.07 % and phosphorus by 0.04 %. The use of an organomineral fertilizer system (Background+ N120P120K90) had a positive effect on the yield of apple trees. Thus, in the non-maneuverable version on a 94–meter furrow, the yield of the apple tree was 274.2 c/ha - when the furrow was lengthened to 192 m, the yield gradually decreased due to the high content of leached nutrients and humus (268.5 c/ha). When using N120P120K90 + 10 t/ha of manure, 278.4 c/ha yield was established at 96 m furrow and 0.2 l/sec of water consumption. Whereas, when the furrow was lengthened to 192 m at the same rate of fertilizers and water consumption, the yield decreased to 278.2 c/ha, that is, furrow lengthening was ineffective at slopes tg = 0.021. It was found that at high slopes, the shorter the furrow, the less nutrients are washed out.

Inter-cropping patterns and nutrient management effects on maize growth, yield and quality

ContextIntercropping, a sustainable agricultural practice, is pivotal in enhancing land use efficiency, soil fertility, and overall crop productivity. This study zeroes in on the dynamics of Maize-Cowpea intercropping in the Alluvial Zone of West Bengal, a region characterized by its fertile soil and diverse agro-ecological conditions. The practice of intercropping, particularly in regions like West Bengal, holds immense potential in revolutionizing traditional farming methods by maximizing yield per unit area while ensuring sustainability. The study aims to unravel the complexities and benefits of this practice, especially in the context of the monsoon dependent Kharif season, which is crucial for agricultural productivity in the region. ObjectivesThe study aims to evaluate the effects of various Maize-Cowpea intercropping patterns and nutrient management strategies on maize growth, yield, and quality during the Kharif seasons of 2019 and 2020. It hypothesizes that intercropping, combined with optimal nutrient management, can significantly enhance maize performance. MethodsEmploying a split-plot design, the study analysed 25 treatment combinations of intercropping and nitrogen fertilization under sub-tropical sub-humid conditions. Advanced quantitative methods, including regression analysis and principal component analysis (PCA), were used to assess the interactions between intercropping systems and nutrient management practices. ResultsThe findings revealed that while sole maize cultivation showed better growth and yield, Maize-Cowpea intercropping, especially in a 1:1 row ratio, significantly increased the total system yield by 13.6%. This method also improved grain quality, notably enhancing crude protein content and nutrient percentage. A combination of 75% recommended dose of nitrogen (RDN) through chemical means with 25% RDN through organic sources, including seaweed, was particularly effective in boosting maize performance. ConclusionsThe study confirms the superior performance of Kharif maize in an intercropping setup, particularly when integrated with cowpea. It demonstrates the effectiveness of specific nutrient management strategies in enhancing both quantitative and qualitative traits of maize. ImplicationsThis research significantly contributes to the field of sustainable agriculture, particularly in the context of field crops research and practice. The findings offer valuable insights for enhancing crop productivity and sustainability in similar agro-ecological regions globally. The study underscores the benefits of integrating legumes with cereals in intercropping systems, paving the way for innovative agricultural practices that can meet the dual challenges of food security and environmental sustainability. The implications of this research are far-reaching, providing a robust framework for future agricultural strategies in regions facing similar climatic and soil conditions.