Total Fruit Yield Research Articles

Effect of Plant Growth Regulators on Growth, Yield and Quality of Strawberry (Fragaria × ananassa Duch.) Cv. Winter Dawn under Open Field Conditions of South Gujarat

Background: The South Gujarat hilly part is considered to be a non-traditional area of strawberry cultivation in India. The poor farmers of this region are cultivating strawberries under open field condition. Both, the yield and quality of strawberry fruits of this region are not up-to-the-mark as there in other parts of the country. Hence, a low-cost improved production technology is required to maximize yield as well as improve the quality of strawberry fruits. Method: Uniform runners of strawberry cv. Winter Dawn were grown in open field under paddy straw as bedding material. Foliar spraying of plant growth regulators viz. NAA (50, 75, 100 and 125 mg l-1) and GA3 (50, 75, 100 and 125 mg l-1) were done at 30 and 60 days after planting. The experiment was laid out in randomized block design with control plants receiving no spray treatments and replicated thrice. Result: The plant growth parameters like plant spread, number of leaves, number of crowns, leaf area, length of petiole, number of runners were recorded maximum with the application of 100 mg l-1 GA3. This treatment was also found to be the best in respect of number of flowers, number of fruits, fruit weight, marketable and total fruit yield of strawberry. Strawberry fruits with the highest total soluble solid, ascorbic acid, reducing sugar, non-reducing sugar and total sugar content were recorded in the plants which received 125 mg l-1 NAA. However, the plant growth regulator treatments failed to influence any significant effect on days taken to 50.0% flowering, fruit firmness and acidity content of strawberry fruits.

High Tunnel Production of Tomatoes for Season Extension in Southeast Alabama

A series of experiments was conducted to evaluate variety selection and planting date for spring and fall season extension of tomato (Solanum lycopersicum L. (syn.: Lycoperisicon esculentum Mill.)) production in high tunnels in southeast Alabama. ‘BHN 640’, ‘Florida 91’, ‘Sun Leaper’, and ‘Carolina Gold’ were evaluated for early spring production in 2004. These varieties did not differ in total yield of marketable fruit; however, ‘BHN 640’ and ‘Sun Leaper’ produced higher early yields compared with the other varieties. ‘BHN 640’ and ‘Florida 91’ were evaluated for late-season extension in fall 2004. ‘BHN 640’ produced higher yields of large, medium, total marketable, and unmarketable fruit grades than ‘Florida 91’. In a study conducted in early 2005, higher yields of marketable fruit were produced from the first planting date (31 January) compared with the final of four planting date (25 Mar.). In summary, results indicated that season extension of tomato production in high tunnels was possible, with harvests three weeks earlier in the spring and 12 weeks later in the fall compared with typical field harvest dates. These early yields can command prices from $3.30 to $4.40US per kg of fruit.

Response of watermelon (Citrullus lanatus) to plant compost, kitchen wastes and chicken manure composted with PGPR microbes as Bio-Organic fertilizers

Field experiments in two different locations were conducted at the Faculty of Agriculture, (Saba-Basha) - Alexandria University, during summer season of 2018/2019. The main objective was to investigate the effectiveness of different combinations of compost types on yield and quality of watermelon (cv.Skata F1 hyprid). The study was conducted with randomized complete block design with three replicates. Seven treatments were carried out in this investigation i.e. (T1-Jojoba leaves compost, T2-Compost A,T3-Compost B, T4-Compost C, T5-Compost D, T6-Compost E and T7- Control treatment (R100% NPK). The effects of the treatments on the growth and yield of watermelon were determined. Application of different types of compost increased the vine length, number of leaves, number of branches, number of fruits/plant, average fruit weight, fruit length, fruit diameter, mineral contents of leaves and fruits and improved total fruit yield. The obtained results indicated generally that application of chicken manure (T6) produced the highest values of all yield and its components and chemical composition of watermelon plants during both locations compared with the inorganic treatment. Also,Jojoba leaves compost (T1) and compost B ( 100% Compost A + PGPR) gave the highest mean values of the chlorophyll content in leaves character. In addition to Compost C ( 50% Compost A + 50% Chicken manure) gave the best results in mineral content of leaves characters. The findings in this study strongly recommended that chicken manure, beneficial microbes (PGPR), plant composted residues and kitchen wastes would be advantage if the farmer's target is to maximize watermelon yield.

Eco-Physiological Properties of Open-Field Cucumbers Responded to Organic Liquid Fertilizers

This study was initiated to determine the effect of organic farm-derived liquid fertilizer (LF) on (1) the performance of open-field cucumbers (Cucumis sativus L.) and (2) the soil environment. Treatments included fertigation with a 0.2% solution of an equal T-N concentration on each LF, including long-term non-treatment (LNT, groundwater), non-treatment (NT, groundwater), oil cake (OC), bone meal + fish residue (BF), fish extract + active phosphoric acid (FP), sesame oil (SO), and starfish (SF). Electrical conductivity (EC) in LF was increased in the SF or BF, with high concentrations of T-C observed in the OC and BF and high P in the SO. LNT treatment decreased soil mineral nutrient concentrations and numbers of bacterial operational taxonomic units, invertebrates, and earthworms, significantly increasing infection of powdery mildew and downy mildew for the plants but reducing foliar concentrations of T-N, P, Ca, and SPAD values, and vegetative growth parameters. Soil bulk density decreased in the SF and SO plots. Total fruit yield and fruit yield efficiency were enhanced by BF, FP, SO, and SF treatments, with the highest top grade values observed on the FP- and SO-fruit. Overall, all the organic LF, in particular the SO treatment, would have improved eco-physiological sustainability and provided an alternative organic fertilizer for a short growing period.

Effects of Grafting on Morphophysiological and Yield Characteristic of Eggplant (Solanum melongena L.) Grafted onto Wild Relative Rootstocks.

Grafting is regarded as an integral component of sustainable vegetable production. It is important in the management of soil-borne diseases, and reports suggest that grafting with viable rootstocks can enhance crop growth and yield. This research was conducted using splices and cleft grafting techniques to investigate graft compatibility among varieties of high yielding eggplant scion (MCV1, MCV2, CCV1, CCV2, CCV3, NCV, and TCV) grafted onto wild rootstocks (MWR, BWR, and TWR) to study their morphophysiological and yield characteristics. High yielding scions grafted onto wild relative rootstocks were compared with two controls including self-grafted and non-grafted. All the scion had a high rate of germination (≥95%) and remarkable graft success (100%) was recorded in MCV1, MCV2, and TCV using the cleft techniques. Generally, the use of rootstocks resulted in higher total and marketable fruit yield compared to the non-grafted and self-grafted scion plants, respectively. In particular, MWR and TWR rootstock conferred the highest vigour to the scion, resulting in the highest values recorded for total and marketable fruit yield, number of fruits per plant and average fruit weight. A similar result was obtained in fruit length and diameter, where long and wide fruits were observed in scions grafted onto MWR and TWR rootstocks, respectively. Grafting of high yielding eggplant scion onto resistant MWR, BWR and TWR eggplant rootstock was found to be beneficial for eggplant cultivation. The remarkable compatibility and vigour of the rootstock with scion led to the improvement in total and marketable yield of the fruits. As such, it can be concluded that the use of wild relative rootstocks of eggplant species can be a valuable method of improving eggplant production.

A Microbial-Based Biostimulant Enhances Sweet Pepper Performance by Metabolic Reprogramming of Phytohormone Profile and Secondary Metabolism.

Microbial-based biostimulants can improve crop productivity by modulating cell metabolic pathways including hormonal balance. However, little is known about the microbial-mediated molecular changes causing yield increase. The present study elucidates the metabolomic modulation occurring in pepper (Capsicum annuum L.) leaves at the vegetative and reproductive phenological stages, in response to microbial-based biostimulants. The arbuscular mycorrhizal fungi Rhizoglomus irregularis and Funneliformis mosseae, as well as Trichoderma koningii, were used in this work. The application of endophytic fungi significantly increased total fruit yield by 23.7% compared to that of untreated plants. Multivariate statistics indicated that the biostimulant treatment substantially altered the shape of the metabolic profile of pepper. Compared to the untreated control, the plants treated with microbial biostimulants presented with modified gibberellin, auxin, and cytokinin patterns. The biostimulant treatment also induced secondary metabolism and caused carotenoids, saponins, and phenolic compounds to accumulate in the plants. Differential metabolomic signatures indicated diverse and concerted biochemical responses in the plants following the colonization of their roots by beneficial microorganisms. The above findings demonstrated a clear link between microbial-mediated yield increase and a strong up-regulation of hormonal and secondary metabolic pathways associated with growth stimulation and crop defense to environmental stresses.

Studies on genetic divergence (D2) for fruit yield and its contributing traits in okra [Abelmoschus esculentus L. Moench

The present investigation entitled “Studies on genetic divergence (D2) for fruit yield and its contributing traits in okra [Abelmoschus esculentus L. Moench]”, was conducted during Kharif 2019. The experiment comprised of thirty genotypes at Main Experimental Station, Department of Vegetable Science, Acharya Narendra Deva University of Agriculture and Technology, Narendra Nagar (Kumarganj), Ayodhya, Uttar Pradesh, India. The study of genetic divergence among the thirty genotypes of okra was carried out using Mahalanobis D2 statistics. The thirty genotypes of were grouped into six different non over lapping clusters Table 1. Cluster II was the biggest consisting of 8 genotypes followed by IV consisting (6 genotypes), V consisting (5 genotypes), cluster I, III (4 genotypes) and cluster VI has 3 genotypes. Experimental material for study consisted of 30 genotypes including three checks (Parbhani Kranti, Pusa Sawani and Pusa Makhmali). The experiment was conducted in Randomised Block Design with three replications. Each genotypes consisted of three rows spaced 60 cm with plant to plant spacing of 30 cm. Observation were recorded for fourteen different characters of okra i.e. node to first flower appearance, days to 50% flowering, plant height (cm), crop duration, number of branches per plant, days to first fruit harvest, number of nodes per plant, total soluble solid (⁰B.), fruit length (cm), fruit circumference (cm), average fruit weight (g), number of fruits per plant, marketable fruit yield per plant (g) and total fruit yield per plant (g).

Effects of Within-row Intercropping with Snow Peas on Yield and Quality of Cherry Tomatoes in an Organic High Tunnel Production System

Intercropping can increase land use efficiency in high tunnel crop production, but it may also lead to decreases in yield and quality of main crops due to the potential competition for resources. This study evaluated the agronomic viability of intercropping snow pea (Pisum sativum L., ‘Ho Lan Dou’) with cherry tomato (Solanum lycopersicum L. var. cerasiforme ‘Sarina hybrid’) without additional inputs of water and fertilizers on peas in an organic high tunnel production system under Southern Ontario climate conditions in Guelph, Ontario, Canada (lat. 43.5 °N, long. 80.2 °W) during 2015 and 2016. In each 80-cm-wide bed, the tomato crops were planted alternately in double rows spaced 30 cm apart, with in-row spacing of 110 cm, which resulted in a planting density of ≈24,000 plants/ha. The snow pea seeds were sown between the tomato plants (i.e., within the same beds as tomatoes) in holes (two seeds per hole), with four rows in each bed and in-row holes spaced 10 cm and at least 25 cm away from the tomato plants, which resulted in a seeding rate of ≈650, 000 seeds/ha. The same amount of water or fertilizer was applied to the intercropping and nonintercropping plots based on the needs of the cherry tomato plants. Plant growth, fruit yield, and quality were compared between tomato plants with and without intercropping. Intercropping with snow peas did not affect total marketable fruit yield, unmarketable fruit percentage, fruit quality traits (e.g., individual fruit weight, soluble solids content, dry matter content, and postharvest water loss), or early-stage plant growth of the cherry tomato. Therefore, it is at least an agronomical possibility to intercrop snow peas with cherry tomatoes on the same beds without additional inputs of water and fertilizer on snow peas in an organic high tunnel system. The additional yield of pea shoots or pods in the intercropping treatment also increased economic gross returns in the high tunnels, although the economic net return might vary with the costs of seeds and labor involved in snow pea growing.

Evaluation of Cluster Bean (Cyamopsis Tetragonoloba (L.) Taub) Genotypes for Fruit and Gum Yield

An experiment on evaluation of cluster bean genotypes was conducted at the department of vegetable crops, Horticultural College and Research Institute, Periyakulam. Fifty genotypes of gum type of cluster bean from NBPGR, Regional Station Jodhpur, two varieties viz., Thar Bhadavi and the check variety Pusa Navbahar were collected for the study. The collected fifty two (Ct - 1 to Ct - 52) genotypes were evaluated for their growth, yield and gum content for three seasons from November 2013 to February 2015. The data collected from the 52 genotypes. The three seasons data were pooled and statistically analysed. From the above study it is concluded that the variety Pusa Navbahar (Ct – 52 check variety) recorded highest total fruit yield per plant, fruit length, number of seeds per fruit and seed yield per plant than other genotypes taken for evaluation. The same genotype Ct - 52 also recorded the highest guar gum content of 13.44 per cent followed by 12.94 per cent in Ct – 39 and the lowest gum yield of 5.79 per cent was observed in Ct - 47.

Parameterization of the AquaCrop model for simulating table grapes growth and water productivity in an arid region of Mexico

Currently, the AquaCrop model has been widely tested for many fruit/grain crops; root and tuber crops; leafy vegetables, or forage crops, but is restricted to annual herbaceous species, while deciduous crops have received less if no attention. In this context, this study aims to test for the first time the ability of the AquaCrop model to simulate canopy cover (CC), actual evapotranspiration (ETa), total soil water content (TWC), biomass (B) and fruit yield (FY) of table grapes vineyards (Vitis vinifera L., cvs. Perlette and Superior) at the Costa de Hermosillo, Sonora in Northwest Mexico. Observed weather and soil physical parameters, with measured crop parameters from an experiment conducted during 2005 were used to develop climate, soil and crop input files for AquaCrop and for calibrating the model. While collected data during the 2006 growing season were used to validate the model. The model adequately simulated CC, ETa and TWC during 2005 and 2006. The Root Mean Square Error (RMSE) between observed and measured CC, ETa and TWC were 5.18%, 0.46 mm/day and 10.11 mm during 2005, and 8.82%, 0.84 mm/day and 9.1 mm during 2006, respectively. The good accuracy of simulations of CC, ETa and TWC by the model have been confirmed by additional statistical parameters like the coefficient of determination (R2), The Mean Bias Error (MBE), the Willmott’s index of agreement (d) and the Nash–Sutcliffe Efficiency (NSE).For the B and FY simulations, the results showed that the model correctly reproduced the B and FY with NRMSE value of 8.8%. The estimated average value of FY (14.56 t/ha) for both seasons are in the range of the potential yield (14–18 t/ha) of table grapes in the irrigated Costa de Hermosillo in northwest Mexico.After the validation of the AquaCrop model, it was used to evaluate the irrigation scheduling by the farmer as well as to assess the water productivity computed as the ratio of crop production to crop water use. The results showed that, the recommended irrigation by the model was about 547 mm and 509 mm, which it is about half of that applied by the farmer (1006 mm and 929 mm) during 2005 and 2006, respectively. This large difference, which represents approximately 54% and 57% of the irrigation supply, is lost through deep percolation and could be saved without vegetation suffering from water stress while maintaining the same yield. The high loss of water by percolation affects significantly the water productivity (WP), which decreases from 3.22 to 1.74 kg/m3 if we consider the transpiration (WPTr), and the sum of ETa and Percolation (WPETa+Pr) for WP computations, respectively. Consequently, the AquaCrop model can be used as an operational tool by decision makers and growers to improve irrigation management. This is of crucial importance in arid and semi-arid regions where water is becoming increasingly scarce.

ICAR-Central Institute for Subtropical Horticulture, Rehmankhera, Lucknow, Uttar Pradesh 226 101, India

Improvement of sustainable yield index (SYI) in fruit crop is the most important aspect of orchard sustainability and economic enhancement of fruit growers for which an investigation was laid out to improve SYI in guava (Psidium guajava L.) cv Shewta under different integrated nutrient management systems. Higher SYI was obtained using organic + inorganic systems (0.66) followed by NPK fertilization in soil (0.67) or foliar application of micronutrients (0.71) as compared to control (0.45) or adoption of sole organic sources of nutrition (0.45). A range of variation in SYI from 0.44 to 0.77 was recorded across treatments and seasons. The Reference ET0 and pan evaporation was varied between 0.82 to 5.33 mm/day and 1.30 to 7.0 mm/day respectively during reproductive stages of guava. Changes in soil physical properties were recorded across three depths (0-10, 10-20 and 20-30 cm); water holding capacity and porosity varied across the depths and treatments; 19.53 to 24.48% and 39.92 to 50.20 % respectively. Improvement in these two parameters might have contributed towards better SYI in guava. The co-efficient of variation (CV%) of guava productivity based on yield stability indicated lower the variation (1.2 to 4.9) higher is the stability. The dynamic variations in total fruit yield 31.4 to 72.5 kg/tree indicated immediate need for precise soil management to enhance yield potentiality. Conclusively for better SYI in guava, the nutrient requirement through organic (FYM, Azotobacter, PSM, organic mulching Trichoderma etc.) and inorganic (NPK, micronutrients) sources are essentially required in soils of inherently low or poor fertility status.

Growth, Productivity, and Quality of Strawberry as Affected by Propagation Method and Cultivation System

This study was conducted to investigate productivity of strawberry plants as affected by propagation method and cultivation system. Transplants propagated by cutting propagation and pinning propagation were planted and grown for a whole production period in soil and hydroponic cultivation systems. Growth parameters, fruit productivity, and fruit quality were measured during the whole harvest period. The results showed that propagation method and cultivation system had significant effects on vegetative growth of strawberry plants. Total fruit yield per plant and average fruit weight per fruit during the whole harvest period were significantly lower in the plants grown in soil cultivation system. Total unmarketable fruit ratio was significantly greater in soil cultivation system than that in hydroponic cultivation system. Small fruits were the primary unmarketable fruits in soil cultivation system, while malformed fruits were the primary unmarketable fruits in hydroponic cultivation system. The overall high quality of fruit was found in February, and the plants cultivated in hydroponic cultivation system had higher quality of fruit as compared with that in soil cultivation system. It is concluded that cutting propagation is better than pinning propagation, and hydroponic cultivation system is better than soil cultivation system for fruit productivity of strawberry.

Melatonin Counteracts Drought Induced Oxidative Damage and Stimulates Growth, Productivity and Fruit Quality Properties of Tomato Plants.

Melatonin “N-Acetyl-5-methoxytryptamine” (MT) has recently been considered as a new plant growth regulator with multiple physiological functions. Although many previous studies have confirmed that exogenous applied-MT can alleviate the deleterious effects of drought stress in many plant species, most of these studies were exclusive on seeds, seedlings, and young plants for a short period of their life cycles. Therefore, the knowledge of using MT as a potential promising agricultural foliar application to improve crop productivity and quality is still insufficient under adverse open field conditions. In this study, we investigated the effect of MT as a foliar application at 0, 20, and 40 ppm on tomato plants that were grown in the open field under the long term of optimal and deficit irrigation conditions. The results indicated that exogenous MT significantly enhanced plant growth, chlorophyll and activities of antioxidant enzymes, including ascorbate peroxidase (APX), catalase (CAT), and peroxidase (POX). This improvement was associated with a marked reduction in proline and soluble sugars. In addition, applied-MT worked as a protective agent against oxidative damage by reducing the cellular content of toxic substances such as H2O2 and malondialdehyde (MDA). Similarly, MT-treated plants showed greater total fruit yield with improving its quality attributes like total soluble solids (TSS), ascorbic acid, and lycopene. Generally, the highest significant fruit yield either under well-watered (13.7%) or water deficit (37.4%) conditions was achieved by the treatment of 20 ppm MT. These results indicate that exogenous MT played an essential role in enhancing tomato tolerance to deficit irrigation and could be recommended as a promising agricultural treatment under such conditions.

Influence of enriched organic manure, biostimulants and bio-mulches on organic okra (Abelmoschus esculentus)

Field experiments were conducted to identify the best source of nutrients and bio-mulch for fruit yield, quality and soil properties of organic okra (Abelmoschus esculentus) at U B K V, Pundibari, West Bengal, India during February- May 2017-18. The experiment was laid out in Factorial RBD comprising of two factors, viz. organic nutrient sources (N) and bio-mulches (M) having four levels each. The findings of the experiment suggested that basal application of Azophos biofertilizer enriched vermicompost (5 t/ha) along with foliar spray of seaweed extract (2 ml/l) at 30, 40 and 50 days of sowing (N4) emerged as best treatment in terms of highest number of fruits (19.94/plant) and maximum yield (14.39 t/ha). Among the different bio-mulches, the vegetable legume plant residue mulch (M4) recorded highest number of fruits (20.79/plant), total fruit yield (14.79 t/ha), maximum ascorbic acid content (18.47 mg/100 g) and increased total chlorophyll content (46.99 mg/100 g). The interaction of N4M4 recorded highest number of fruit (22.88/ plant), fruit yield (348.08 gm/plant), total yield (16.68 t/ha) and the maximum total fruit chlorophyll content (51.60 mg/100 g). All the interaction of organic nutrient sources and bio-mulches showed increase in available N, P, K and organic carbon content in post harvest soil over the initial status. The study concluded that adoption of biofertilizer enriched vermicompost in combination with 3 times foliar spray of seaweed extract in standing crop with legume as mulch have significant positive impact on fruit yield, quality and soil properties of organic okra.

Soil environment and spectra properties coregulate tomato growth, fruit quality, and yield in different colored biodegradable paper mulching during the summer season

Plastic film (PF) is the primary material applied for soil mulching, but it may also cause heat and drought stresses to crops in the summer season. In a previous study, we revealed that biodegradable paper (BP) was a potential mulching material for summer crop production, because it could not only decrease soil temperature, but also increase soil moisture during the summer season. However, it is still unclear whether different colored BPs have various efficiencies in improving soil environment, when used as soil mulching materials. Therefore, in this study, gray PF and different colors (red, dark, blue and yellow) of BPs were used as soil mulching materials to explore their influences on soil temperature and moisture, spectral and photosynthetic characteristics, plant growth, and fruit quality and yield of tomato in the summer season. The non-mulching (NM) served as control. In general, PF exhibited the highest illuminance and photosynthetic irradiance, and thereby led to the highest soil temperature. However, soil temperature decreased on average of 5.73% and 20.28% in BPs as compared to NM and PF, respectively. Soil moisture increased on average of 8.15%, 5.41%, and 10.98% in dark, red, and blue BPs, respectively, as compared to NM. The ratio of blue-violet to red-orange irradiance were 1:2, 2:3, 1:4, 1:3, and 1:1 in NM, PF, yellow BP, red BP, and blue BP, respectively. The red and blue BPs generally enhanced root growth, and thereby increased total fruit yield by 36.56% and 41.64% on average, respectively, as compared to PF. In addition, an overall improvement in fruit quality (vitamin C, soluble sugar, and sugar-acid ratio) was observed in red and blue BPs as compared to PF and other colored BPs. Our results demonstrated that red and blue BPs can be applied to improve soil environment and spectral characteristics, and thereby enhance fruit yield and quality, during the summer crop production.

Plant spatial arrangement on growth, weed control, and yield of okra

ABSTRACT Light interception by okra [Abelmoschus esculentus (L.) Moench] can be altered by changing row and plant spacing and plant/row orientation. In okra, reduction in yield can occur due to improper planting arrangement, use of inappropriate cultivar, weed interference, and ineffective weed control. A field experiment was conducted at the Federal University of Agriculture, Abeokuta, Nigeria, to assess the effects of planting arrangement on okra and on its ability to control weeds. Cultivars NHAe 47–4 and LD 88 were established at a population of 40,000 plants∙ha−1 as a result of spatial arrangement using 100 cm inter-row distance and respective intra-row distances of: 25 cm with 1 plant/stand; 50 cm with 2 plants/stand, and 75 cm with 3 plants/stand. Data were collected on number of leaves, plant height, stem diameter, leaf area, days to first flowering, days to 50% flowering; total fruit yield, weed density, weed fresh weight, and weed dry matter content. Cultivar and planting arrangement affected growth, yield, and weed interference. More and wider, leaves with taller plants were produced by cv. NHAe 47–4 planted at 1 plant/stand. Cultivar LD 88 planted at 1 plant/stand produced wider stems, higher yields and best weed suppression (7 weeds.m2) while earlier flowering was observed at 2 plants/stand. The days to 50% flowering was similar for cv. NHAe 47–4 planted at 1 or 2 plants/stand and ‘LD 88ʹ planted at 2 plants/stand. Cultivar LD 88 planted at 1 plant/stand had higher yield and suppressed weeds best, 7 weeds∙m2. Plant spatial arrangement can affect growth and yield. The best planting arrangement for a crop could have impact on productivity and cost of production. The late-maturing cv. LD 88 planted at 100 × 25 cm at 1 plant/stand produced optimum okra growth, yield, and efficient weed control in a traditional cropping system in the tropics.

Light‐limited photosynthesis under energy‐saving film decreases eggplant yield

AbstractGlasshouse films with adjustable light transmittance and energy‐efficient designs have the potential to reduce (up to 80%) the high energy cost for greenhouse horticulture operations. Whether these films compromise the quantity and quality of light transmission for photosynthesis and crop yield remains unclear. A “Smart Glass” film ULR‐80 (SG) was applied to a high‐tech greenhouse horticulture facility, and two experimental trials were conducted by growing eggplant (Solanum melongena) using commercial vertical cultivation and management practices. SG blocked 85% of ultraviolet (UV), 58% of far‐red, and 26% of red light, leading to an overall reduction of 19% in photosynthetically active radiation (PAR, 380–699 nm) and a 25% reduction in total season fruit yield. There was a 53% (season mean) reduction in net short‐wave radiation (radiometer range, 385–2,105 nm upward; 295–2,685 nm downward) that generated a net reduction of 8% in heat load and reduced water and nutrient consumption by 18%, leading to improved energy and resource use efficiency. Eggplant adjusted to the altered SG light environment via decreased maximum light‐saturated photosynthetic rates (Amax) and lower xanthophyll de‐epoxidation state. The shift in light characteristics under SG led to reduced photosynthesis, which may have reduced source (leaf) to sink (fruit) carbon distribution, increased fruit abortion and decreased fruit yield, but did not affect nutritional quality. We conclude that SG increases energy and resource use efficiency, without affecting fruit quality, but the reduction in photosynthesis and eggplant yield is high. The solution is to re‐engineer the SG to increase penetration of UV and PAR, while maintaining blockage of glasshouse heat gain.

Chlorophyll Fluorescence Parameters and Antioxidant Defense System Can Display Salt Tolerance of Salt Acclimated Sweet Pepper Plants Treated with Chitosan and Plant Growth Promoting Rhizobacteria

Salinity stress deleteriously affects the growth and yield of many plants. Plant growth promoting rhizobacteria (PGPR) and chitosan both play an important role in combating salinity stress and improving plant growth under adverse environmental conditions. The present study aimed to evaluate the impacts of PGPR and chitosan on the growth of sweet pepper plant grown under different salinity regimes. For this purpose, two pot experiments were conducted in 2019 and 2020 to evaluate the role of PGPR (Bacillus thuringiensis MH161336 106–8 CFU/cm3) applied as seed treatment and foliar application of chitosan (30 mg dm−3) on sweet pepper plants (cv. Yolo Wonder) under two salinity concentrations (34 and 68 mM). Our findings revealed that, the chlorophyll fluorescence parameter (Fv/Fm ratio), chlorophyll a and b concentrations, relative water content (RWC), and fruit yield characters were negatively affected and significantly reduced under salinity conditions. The higher concentration was more harmful. Nevertheless, electrolyte leakage, lipid peroxidation, hydrogen peroxide (H2O2), and superoxide (O2−) significantly increased in stressed plants. However, the application of B. thuringiensis and chitosan led to improved plant growth and resulted in a significant increase in RWC, chlorophyll content, chlorophyll fluorescence parameter (Fv/Fm ratio), and fruit yield. Conversely, lipid peroxidation, electrolyte leakage, O2−, and H2O2 were significantly reduced in stressed plants. Also, B. thuringiensis and chitosan application regulated the proline accumulation and enzyme activity, as well as increased the number of fruit plant−1, fruit fresh weight plant−1, and total fruit yield of sweet pepper grown under saline conditions.

Deficit Irrigation and Arbuscular Mycorrhiza as a Water-Saving Strategy for Eggplant Production

Crop production in arid regions requires continuous irrigation to fulfill water demand throughout the growing season. Agronomic measures, such as roots-soil microorganisms, including arbuscular mycorrhizal (AM) fungi, have emerged in recent years to overcome soil constraints and improve water use efficiency (WUE). Eggplant plants were exposed to varying water stress under inoculated (AM+) and non-inoculated (AM−) to evaluate yield performance along with plant physiological status. Plants grown under full irrigation resulted in the highest fruit yield, and there were significant reductions in total yield and yield components when applying less water. The decline in fruit yield was due to the reduction in the number of fruits rather than the weight of the fruit per plant. AM+ plants showed more favorable growth conditions, which translated into better crop yield, total dry biomass, and number of fruits under all irrigation treatments. The fruit yield did not differ between full irrigation and 80% evapotranspiration (ET) restoration with AM+, but a 20% reduction in irrigation water was achieved. Water use efficiency (WUE) was negatively affected by deficit irrigation, particularly at 40% ET, when the water deficit severely depressed fruit yield. Yield response factor (Ky) showed a lower tolerance with a value higher than 1, with a persistent drop in WUE suggesting a lower tolerance to water deficits. The (Ky) factor was relatively lower with AM+ than with AM− for the total fruit yield and dry biomass (Kss), indicating that AM may enhance the drought tolerance of the crop. Plants with AM+ had a higher uptake of N and P in shoots and fruits, higher stomatal conductance (gs), and higher photosynthetic rates (Pn), regardless of drought severity. Soil with AM+ had higher extractable N, P, and organic carbon (OC), indicating an improvement of the fertility status in coping with a limited water supply.

Plant density due to intra-row spacing on growth, weed control, and yield of Golden melon

ABSTRACT Appropriate density of Golden melon (Cucumis melo L.) in the field is arrived at by correct spacing between, and within rows, a factor that can impact on weed incidence and crop yield. A field experiment was conducted at the Federal University of Agriculture, Abeokuta, in the tropical rainforest/savannah transition zone of southwestern Nigeria, to assess the effects of intra-row spacing on growth and yield of golden melon and determine the weed control ability. Treatments were plant densities of: 50,000, 25,000, 16,667, 12,500, or 10,000 plants∙ha−1 produced by establishing plants at 20, 40, 60, 80, or 100 cm intra-row with a constant inter-row spacing of 100 cm. Data were collected on number of leaves, vine length, number of branches, days to flowering, days to 50% flowering, number of fruits per plant, average fruit weight, total fruit yield, weed density, weed fresh weight, and weed dry matter content. More leaves, branches, and longer vines were obtained from plants grown at 10,000, 12,500, and 16,667 plants∙ha−1. Number of fruits per plant increased as plant density increased. Planting at 25,000 and 50,000 plants∙ha−1 produced smaller fruits compared to planting at 10,000 and 16,667 plants∙ha−1. Planting at 10,000 and 16,667 plants∙ha−1 produced more fruits per plant and had larger fruits compared to other plant densities. Planting golden melon at a population density of 25,000 or 50,000 plants∙ha−1 was efficient in controlling, and reducing, weed interference. Planting at a population of 25,000 plants∙ha−1 provides efficient weed control; a population of 16,666 plants∙ha−1 provides increased growth and yield of golden melon. Planting Golden melon at a population of 16,666 plants∙ha−1 (100 cm inter-row, 60 cm intra-row spacing) appears to be best to improve yield. Knowledge of the best plant density obtained through intra-row spacing can impact efficiency and cost of production of Golden melon.