Marketable Fruit Yield Research Articles

Response of cucumber (Cucumis sativus L. Cv. Bhaktapur local) to the application of plant growth regulators in plastic tunnel

The field experiment was conducted to know the yield performance of cucumber var. Bhaktapur Local with the application of plant growth regulators (PGRs) in the farmers’ field of Lamjung, Nepal during September to November, 2013. Five treatments (Four PGRs; NAA @10 ppm, GA3 @ 50ppm, GA3 @100ppm, MH@ 60ppm and distilled water as control) were replicated six times under walk-in plastic tunnel. The experiment was laid out in randomized complete block design. The first 30 flowers of each plant were used for the observation. PGRs were sprayed in 2-4 true leaf stage of seedling, 20 days after first spray and 10 days after second spray. The research revealed that NAA @ 10 ppm had higher effect in sex expression, fruit set and yield than rest of the treatments. GA3 @ 100 ppm had significantly higher number of male flowers and more vine growth than other treatments. Branch per plant was obtained as the highest with MH @60 ppm followed by NAA @10 ppm. The marketable fruit yield was significant with NAA @10 ppm followed by MH@ 60 ppm, GA3 @50 ppm, GA3 @100 ppm than control. It is concluded that thermo-sensitive variety of cucumber Bhaktapur Local can be grown with the use of plant growth regulators particularly, NAA@ 10 ppm, under walk-in plastic tunnels during the autumn-winter season in the mid hills of Nepal. The research further indicated that cucumber can be a profitable and a potential agriculture enterprise for the area.

Mitigation of Chilling Stress by Ozone Pretreatment and Acclimation of Sweet Pepper Grown under Unheated Greenhouse Conditions

Ozone is an important air pollutant that causes many challenges for human health, such as lung diseases. The negative impacts of exogenous ozone on cultivated plants have been discussed in several publications, but the positive impacts are less investigated. The current study is an attempt to answer the following question: is there any positive contribution of ozone pretreatment in growing plants under stress? Plants grown in unheated plastic greenhouses suffer from cold stress during the winter when the temperature drops to 5–10 °C. This stress can also be enhanced under saline soil conditions in arid regions. Treatments involving different ozone application methods (seed priming and seedling foliar application) and cold pretreatment (4 °C for 36 h) were compared with untreated controls of two sweet pepper hybrids (Zidenka and Lirica) in an unheated plastic greenhouse. In general, the Lirica hybrid outperformed the Zidenka hybrid in growth and fruit yield and showed good adaptation to cold stress resulting from ozone treatment through foliar application on seedlings. Moreover, cold treatment was associated with higher values of the studied parameters compared to the control (untreated). A concentration of 20 ppm of ozone in the first season and as 30 ppm of ozone in the second season increased plant leaf area, proline content, and APX activity, all of which improved the plant’s defense mechanisms against cold stress. These benefits contributed to high fruit sets; early, total, and marketable fruit yields; and fruit quality under cold stress. The highest yield (16.52 kg m−2) was attained with 30 ppm ozone applied as a seedling spray, compared with 10.07 kg m−2 in the control. Therefore, the foliar application of ozone up to 30 ppm can be recommended for sweet pepper hybrids of Lirica under unheated plastic greenhouse conditions. Further investigations are needed to study the interaction of combined ozone and cold stress, as well as various levels of soil salinity.

Agro-morphological characterization of bottle gourd [Lagenaria siceraria (Mol.) Standl.] germplasms in Garo Meghalaya hills,

The field experiment was carried out at Horticulture Farm, Department of Horticulture, North Eastern Hill University to evaluate bottle gourd germplasms for horticultural traits and to identify superior genotypes in 30 local bottle gourd genotypes during 2018 and 2019. The experiment was conducted using a randomized block design with three replications. The germplasm lines have been collected from places of Garo Hills districts of Meghalaya. The collected accessions exhibited a wide range of morphological diversity for qualitative as well as for quantitative traits. The grand mean of yield of marketable fruit (kg/plant) was 32.39 kg with the lowest fruit yield/plant of 14.87 kg recorded in GHA-18 and the highest fruit yield of 63.74 kg, fruit yield/plant recorded in GHGA-8. A wide range of variation was recorded for all the characters which indicated that there was better scope for selection for the improvement of these characters.

Heritable variation and trait relatedness in smooth gourd (Luffa cylindrica L.) genetic resources of Assam

Aim: The North-Eastern Region (NER) of India is endowed with enormous variability in genetic resources of smooth gourd. The present investigation was carried out to assess the hereditary variation and determine the trait relatedness in a collection of smooth gourd germplasm. Methodology: The experiment was conducted in a Randomized Complete Block Design with thirty-three smooth gourd germplasm consisting of thirty germplasm collected from Assam, two collected from Nagaland while another (Pusa Sneha) collected from IARI, New Delhi. Genetic variability parameters were estimated using standard statistical methodology. Results: The percent estimates of both genotypic coefficient of variability (31.36) and phenotypic coefficient of variability (31.83) were found to be the largest in respect of primary branches per plant. Higher estimates of both heritability in broad sense (>60%) and genetic advance as per cent of mean (>20%) were observed for the traits. Marketable fruit yield per plant had highly significant positive correlation with the number of primary branches, internodes, female flowers and fruits per plant and the weight of fruit. At genotypic level, path analysis revealed large direct effects of fruits per plant and fruit weight on marketable fruit yield. Interpretation: High h2 coupled with high GAM observed for the characters substantiates that inheritance of these characters could largely be due to genes with additive effects. Simple selection methods such as mass selection without progeny testing would be efficient for improving the population with respect to such characters. Selecting plants having higher mean values for genetically correlated traits would enhance the marketable fruit yield. Key words: Correlation, Heritability, Smooth gourd, Variability

First Report of Field Efficacy and Economic Viability of Metarhizium anisopliae-ICIPE 20 for Tuta absoluta (Lepidoptera: Gelechiidae) Management on Tomato

Eco-friendly pest control options are highly needed in food crop production systems to mitigate the hazards of synthetic chemical pesticides. Entomopathogenic fungal biopesticides—Metarhizium anisopliae strains ICIPE 20 (oil-formulation containing 1.0 × 109 conidia/mL) and ICIPE 69 (commercialized biopesticide known as Mazao Campaign®)—were evaluated against Tuta absoluta on tomato through inundative foliar spray and compared with the commonly used pesticide Dudu Acelamectin 5% EC (Abamectin 20 g/L + Acetamiprid 3%) and untreated plot. All the treatments were arranged in a randomized complete block design with three replicates. The field experiments were conducted for two consecutive cropping seasons in Mukono district, Uganda. Tuta absoluta infestation, injury severity on leaves and fruits, fruit yield loss, marketable fruit yield gain and cost–benefit ratio of the treatments were assessed. The results during both seasons showed a significant lower fruit yield loss in M. anisopliae ICIPE 20-treated plots compared to untreated plots, with a marketable fruit yield gain exceeding 22% and a cost–benefit ratio greater than 2.8 (BCR~3). Dudu Acelamectin 5% EC outperformed all the other treatments, but needs to be considered with caution due to its non-target effect and resistance development, whereas M. anisopliae ICIPE 69 performed the least well. In addition, the findings showed the high degree of efficacy and economic viability of these biopesticides as a potential T. absoluta control option in the field. However, it is important to further explore different formulations of these eco-friendly biopesticides, inoculum delivery approach, application frequency, their effectiveness in different agro-ecological zones and compatibility with commonly used pesticides in tomato production systems for sustainable management of T. absoluta.

Effects of Mulching and Amount of Water on Yield and Yield Components of Tomato under Drip Irrigation at Adola Rede District, Southern Ethiopia

Water has been recognized as one of the scarcest inputs, which can severely avoid agricultural production and productivity unless it is carefully conserved and managed. This study has investigated the effects of mulching and amount of water on yield and yield components of tomato ( Solanum Lycopersicum L.) under drip irrigation at Adola rede District, Southern Ethiopia. The treatments of the study involved combination of three drip irrigation levels (100, 75, and 50% of crop water requirement, ETc) and three mulches (No mulch, white polyethylene sheet, and wheat straw). The yield and yield components in the mulched treatment with excessive stages of irrigation have been considerably higher in compared to these in the unmulched treatments. The yield of tomatoes increased with the growing quantity of irrigation water in mulched treatments. The highest marketable fruit yield for each mulch (35478kg ha -1 for white mulch and 28831kg ha -1 for straw mulch) was obtained when 75% of the crop water requirement used to be applied. With 100% water application, the white plastic mulched treatment produced a decrease marketable fruit yield than the straw-mulched treatment. The best water productivity of (12.915kg m -3 ) was received with 75% water application under white plastic mulch, But statistically non-significant with straw mulch under 75% crop water requirement application. The highest net benefit of 563475.7ETB ha -1 was recorded from white plastic mulch with 75% ETc and followed by 484454.7ETB ha -1 with Straw mulch with 75% ETc. The lowest net advantage 285477.3ETB ha -1 was acquired from no mulch with 50% ETc. The lowest net benefit to cost ratio was gained under treatment straw mulch with 75% ETc (15.04) and followed by no mulch with 100% ETc (14.32). This end result showed that wheat straw mulch with 75% ETc is economically feasible for tomato production in the Adola area of the Guji zone. Keywords: Crop Water Requirement, Tomato, Drip, Mulching, Water Levels, Marketable Fruit Yield DOI: 10.7176/JEES/12-11-01 Publication date: November 30 th 2022

Mitigating the Adverse Effects of Semi-Arid Climate on Capsicum Cultivation by Using the Retractable Roof Production System.

Capsicum (Capsicum annuum L.) belongs to the Solanaceae family and is an economically important vegetable crop. However, the crop is very sensitive to adverse weather conditions such as high temperatures and excessive sunlight, which cause flower and young fruit to drop and sunscald to mature fruits. Using protected cultivation such as shade covers or net houses is a feasible agronomic approach to protect the crop from high light intensity, which increases plant growth, reduces fruit damage, and increases marketable fruit yield and quality. Low-cost protected cropping options such as fixed-roof net houses have proved cost-effective and suitable for fruiting vegetable production in semi-arid climatic regions. However, this structure type is unable to protect the crops from rainfall, is prone to cyclone damage and is inflexible to accommodate various vegetable crops which have different requirements for healthy and productive growth. This study was conducted in Carnarvon, which has semi-arid climatic conditions and is a key horticultural district of Western Australia, to compare the Retractable Roof Production System (RRPS) and open field (OF) conditions in the production of capsicum. The data showed that the RRPS modified the internal light, temperature and humidity in favour of the capsicum crop. The RRPS-grown capsicum had higher plant height and lower canopy temperature on hot days than those in the OF. The mean marketable fruit yield of capsicum varieties grown in the RRPS was significantly higher than those in the OF with fruit yields of 97 t ha−1 and 39.1 t ha−1, respectively, but the fruit quality remained unchanged. Overall, the data suggest that the RRPS altered the internal microenvironment and enhanced capsicum crop growth, physiology and fruit yield by setting climatic parameters to automatically control the opening and closing of the roof, the insect net and side curtains, and activation of the fogging system. The future perspective of the deployment of RRPS for capsicum production under climatic conditions in Carnarvon was also discussed.

Physiological studies on eggplant (Solanum melongena) grown under drought conditions

Field experiment was conducted during the two growing seasons of 2019 and 2021, at Dokki region, El-Giza Governorate, Egypt, in order to investigate the effect of deficit irrigation (DI) treatments: 100% (control), 70% and 50% of ETo (Reference evapotranspiration) and two irrigation systems: Surface drip irrigation (SDI) and Subsurface irrigation (SSI)porous pipe (20.0cm soil depth) on vegetative growth, chemical constituents, fruit yield and quality of eggplant plants (Cultivars : “Classic” “Swad Eleil”). Results revealed that, DI treatments significantly decreased the vegetative growth, total yield ,marketable yield, leaf relative water content (LRWC) and membrane stability index (MSI) of eggplant plants, compared to control treatment (100% ETₒ). While, water stress treatments improved leaves proline content, alkaloids and irrigation water use efficiency (IWUE). Using SSI (porous pipe) system significantly increased plant height, fresh weight, total yield, marketable fruit yield of eggplant, LRWC and MSI, “Classic” cv had the highest total yield and total marketable yield under the subsurface irrigation system compared to “Swad El-Layl”cv. Regarding, the effect of interaction between DI treatments and irrigation systems, the results illustrated that application of irrigation water with 100% ET0 by SSI system produced the highest significant values of vegetative growth, fruit yield.

Genetic Variability and Scope of Response to Selection in Tomato (Solanum lycopersicum L.)

The present investigation was carried out in randomized block design with three replications during Rabi season of 2020-21 to judge the extent of genetic variability and scope of selection among thirty-two genotypes including two checks of tomato Narendra Tomato-4 (NDT-4) & Narendra Tomato -7(NDT-7) for fourteen characters. In present study the analysis variance showed that all the treatments were significantly different for all the characters. Which, indicates wide range of genetic variability among the available genotypes. On the basis of mean performance, five genotypes namely NDT-28, NDT-29, NDT-30, NDT-32 and NDT-P were promising ones. High genotypic (GCV) and phenotypic (PCV) coefficient of variations were recorded for plant height, number of primary branches, polar diameter of fruit, equatorial diameter of fruit, locules per fruit, average fruit weight, marketable fruit yield per plant and total fruit yield per plant. Moderate genotypic coefficients of variation and phenotypic coefficients of variation were estimated for ascorbic acid content, number of fruits per plant and pericarp thickness. In contrast, low environment coefficient of variation was found for all the characters. High heritability (broad sense) coupled with high genetic advance in per cent of mean was observed for plant height, equatorial diameter of fruit, locules per fruit, pericarp thickness, average fruit weight, number of fruits per plant, marketable fruit yield per plant and total fruit yield per plant. Thus, ample variability is there and selection will be effective among the available germplasm of tomato.

Genetic variability and correlation analysis for yield and yield contributing characters in brinjal (Solanum melongena L.)

Thirty brinjal genotypes were evaluated for eighteen quantitative characters in a randomized block design with three replications. Variability studies for 18 quantitative characters revealed that the phenotypic coefficient of variation (PCV) was comparatively greater than the corresponding genotypic coefficient of variation (GCV) for all the characters studied. Maximum PCV (59.49%) and GCV (59.48%) were registered for fruit weight. High estimates of heritability accompanied with high genetic advance as per cent of mean were  recorded for most of the traits viz., fruit length, diameter, pedicel length, pedicel thickness, relative fruit calyx length, fruit weight, fruits per plant, the number of marketable fruits, marketable fruit yield and fruit yield per plant indicating the prominence of additive gene action, thus pointing towards the effectiveness of simple selection depending on the phenotypic expression of genotypes would be rewarding for genetic improvement of these characters. Significant positive correlation of fruit yield per plant at both genotypic and phenotypic levels with plant height, percentage of medium and long styled flowers, fruit setting percentage, fruit length, fruit diameter, fruit pedicel length, fruit pedicel thickness, fruit weight, marketable fruit yield and significant negative correlation with the number of primary branches, days to 50% flowering, days to first harvest, relative fruit calyx length, fruits per plant, total marketable fruits. Therefore, considering these characters would be beneficial in the selection for fruit yield per plant. Keywords: Brinjal, Genetic variability, Correlation analysis

A photosynthetic bacterial inoculant exerts beneficial effects on the yield and quality of tomato and affects bacterial community structure in an organic field.

Plant growth-promoting rhizobacteria (PGPR) are microorganisms that promote plant health and play a critical role in sustainable agriculture. As a PGPR, Rhodopseudomonas palustris strain PS3, when applied as a microbial inoculant, exhibited beneficial effects on a variety of crops. In this study, we investigated the effects of PS3 on tomato growth, soil properties, and soil microbiota composition in an organic field. The results demonstrated that PS3 inoculation significantly improved the yield of marketable tomato fruit (37%) and the postharvest quality (e.g., sweetness, taste, vitamin C, total phenolic compounds, and lycopene). Additionally, soil nutrient availability (35–56%) and enzymatic activities (13–62%) also increased. We detected that approximately 107 CFU/g soil of R. palustris survived in the PS3-treated soil after harvest. Furthermore, several bacterial genera known to be associated with nutrient cycling (e.g., Dyella, Novosphingobium, Luteimonas, Haliangium, and Thermomonas) had higher relative abundances (log2 fold change >2.0). To validate the results of the field experiment, we further conducted pot experiments with field-collected soil using two different tomato cultivars and obtained consistent results. Notably, the relative abundance of putative PGPRs in the genus Haliangium increased with PS3 inoculation in both cultivars (1.5 and 34.2%, respectively), suggesting that this genus may have synergistic interactions with PS3. Taken together, we further demonstrated the value of PS3 in sustainable agriculture and provided novel knowledge regarding the effects of this PGPR on soil microbiota composition.

Variability and association studies for yield and quality characters among bacterial wilt tolerant advanced breeding lines of bell pepper (Capsicum annuum L.)

Forty-three bell pepper genotypes collected from indigenous and exotic sources were evaluated during summer-rainy season, 2018 at Palampur to estimate genetic parameters of variability, heritability, genetic advance and correlation coefficient for yield and quality characters. Results revealed that significant variations were found among genotypes, indicating that yield and quality traits have enough variations. For all the traits studied, recorded values of phenotypic coefficients of variation (PCV) were greater than genotypic coefficients of variation (GCV). GCV was shown to be highest for marketable fruit yield per plant followed by capsanthin content and heritability was observed to be highest for capsanthin content followed by vitamin C. The three characters viz., marketable fruit yield per plant, capsanthin content, and vitamin C have shown high heritability coupled with high genetic advance as a percentage of mean suggesting the predominance of additive genetic control. High heritability coupled with moderate genetic advance was observed in pericarp thickness and TSS indicated the role of slightly additive gene action. Although TSS had a significant negative correlation with Vitamin C, the capsanthin content showed a positive correlation. Vitamin C and capsanthin content had a strong positive correlation with pericarp thickness; however, TSS had a significant negative correlation. There was no significant association between any of the quality parameters and marketable fruit yield per plant indicating that these traits can be improved independently.

Variability and association studies for yield and quality characters among bacterial wilt tolerant advanced breeding lines of bell pepper (Capsicum annuum L.)

Forty-three bell pepper genotypes collected from indigenous and exotic sources were evaluated during summer-rainy season, 2018 at Palampur to estimate genetic parameters of variability, heritability, genetic advance and correlation coefficient for yield and quality characters. Results revealed that significant variations were found among genotypes, indicating that yield and quality traits have enough variations. For all the traits studied, recorded values of phenotypic coefficients of variation (PCV) were greater than genotypic coefficients of variation (GCV). GCV was shown to be highest for marketable fruit yield per plant followed by capsanthin content and heritability was observed to be highest for capsanthin content followed by vitamin C. The three characters viz., marketable fruit yield per plant, capsanthin content, and vitamin C have shown high heritability coupled with high genetic advance as a percentage of mean suggesting the predominance of additive genetic control. High heritability coupled with moderate genetic advance was observed in pericarp thickness and TSS indicated the role of slightly additive gene action. Although TSS had a significant negative correlation with Vitamin C, the capsanthin content showed a positive correlation. Vitamin C and capsanthin content had a strong positive correlation with pericarp thickness; however, TSS had a significant negative correlation. There was no significant association between any of the quality parameters and marketable fruit yield per plant indicating that these traits can be improved independently.

Effect of Soil Regenerative Practice on Selected Soil Physical Properties and Eggplant (Solanum melongena L.) Yield

Living mulches can play a crucial role in the protection of the soil against erosion, as well as biological and chemical degradation. Soil fertility and its physical properties, including soil structure, are of special importance to crops. Soil physical properties are affected, among other factors, by the type of tillage. In order to determine the effect of regenerative practice (living mulches) on soil physical properties, a two-factorial experiment was conducted. The first factor involved white clover and perennial ryegrass as an intercropping of eggplant. The second factor was the living mulches sowing term: three weeks before eggplant planting, at the time of planting and three weeks after eggplant planting. Covering eggplant inter-rows with living mulches reduced eggplant yield and was beneficial to soil structure and improved water resistance of soil aggregates. Perennial ryegrass had a slightly more advantageous effect on yield and improvement of soil physical properties, as compared to white clover. The greater eggplant fruit yield was obtained from vegetable grown without companion plants. The application of living mulches (especially Trifolium repens L.) caused a non-significant decrease in eggplant fruit yield. It was found that limiting the growth of seedlings sown on the first date result in a decrease in marketable fruit yield (on average 14%). A similar result occurred when living mulches were sown on the planting date of eggplants and difference between the yields was 4.3%. The first term of sowing living mulches—three weeks before eggplant planting—no significantly affected the mean weighted diameter of soil aggregate (MWDg), the water stability index (ΔMWD), the index of waterproof index (Wod) and the soil structure index (W). Later sowing terms resulted in the improvement of the majority of the parameters; however, this was not confirmed statistically. Soil with periodic mechanical treatment of inter-rows showed the 3–4% lower values of soil porosity, 3–16% increased compactness, as well as 28–30% lower indices soil structure and 28–30% for water resistance of soil aggregates compared to the living mulches system.

Growth and Yield Evaluation of Avocado (Persea americana) Varieties in Lowland Agro Ecology of Raya Azebo, Southern Zone of Tigray Region, Northern Ethiopia

Avocado is among the subtropical fruit crops produced in Ethiopia; however, the production and Productivity of avocado is influenced by different factors; of which lack of improved and well adapted varieties are the major one. So, an experiment was conducted at Fachagama from 2013 to 2019 to evaluate and select the best adaptable avocado variety/ies at Raya Valley. Six avocado varieties namely Ettinger, Fuerte, Pinkarton, Hass, Naba and Bacon were laid in RCBD and replicated three times. To achieve the objective, the growth, phenological and yield data were collected and analyzed using SAS software. Accordingly, above graft union stem girth diameter was significantly (P≤0.01) affected by variety, while tree height and canopy diameter were not significantly ascertained by variety. All the tested avocado fruit yield parameters were significantly (P≤0.01) influenced by variety throughout the three years except marketable fruit yield tree-1 and the total yield tree-1 which was not significantly (P≥0.5) determined by variety during 2017 fruit harvesting year. Variety exerted significant (P≤0.01) variation on fruit length (cm) fruit weight (g) and seed weight respectively, throughout the three years (2016-2018), the two years (2017 and 2018) and the two years (2016 and2018). The highest girth diameter (61.44mm) was obtained on Nabal variety. Likewise, the highest (15.51 and18.88kg tree-1) total yield was recorded in Pikerton and Bacon varieties respectively during 2016 and 2018 respectively. From the result Pinkerton and Bacon are recommended for Raya Valley and other areas having similar agro-ecologies. However, it is important to consider the water requirements in terms of irrigation depth and frequency of avocado.

Fruit quality and marketability of Okra (Abelmoschus esculentus (L.) Moench) as influenced by biochar rates and weeding regime

The field trials were conducted at the growing season of 2020 and 2021 at the Federal University of Agriculture, Abeokuta, Ogun State, Nigeria. The objective of the study was to evaluate influence of weeding regime on fruit quality and marketability of okra fruit under different rates of biochar. Split-plot arrangement in a randomized complete block design with three replicates was adopted in the trials. Main plot treatments were three levels of biochar at 0 tha−1, 10 tha−1 and 20 tha−1, while sub plots treatments consisted of four weeding regimes. Data collected were subjected to analysis of variance and treatment means were separated using least significant difference at p ≤ 0.05. The results showed that application of biochar resulted in wider stem, higher leaf area index and marketable fruit yield than the control. Also, a more intense control of weeds was associated with a higher fruit quality and marketability . Uncontrolled weed infestation for whole season caused 96.3% and 92.2% reduction in okra marketability in 2020 and 2021, respectively.

Productive and Physico-Chemical Parameters of Tomato Fruits Submitted to Fertigation Doses with Water Treated with Very Low-Frequency Electromagnetic Resonance Fields.

It is known that poorly performed fertigation directly impacts on tomato production and biometric components. In addition, consumers are also affected by interrelated characteristics that interfere with the acceptability of the fruit, such as the physicochemical parameters and nutrients in the fruit. Thus, eco-friendly technologies, such as irrigation with ultra-low frequency electromagnetic treated-water, which attenuates the inadequate management of fertigation, are essential to improve marketable fruit yields. Thus, the objective of the present work was to investigate the impact of treated water with very low-frequency electromagnetic resonance fields in physical, chemical and nutritional parameters at different nutrient solution strengths in tomato fruits. In this study, experiments were carried out in randomized blocks and five doses of fertigation were used (1.5; 2.5; 4.0; 5.5; and 7.0 dS m−1), employing two types of water: electromagnetically treated and untreated. It can be seen that the fertigation affected some parameters, mainly the number of fruits with blossom-end rot, fruit size, and weight. Variance analysis (ANOVA) was performed with the subsequent use of the Tukey test. In all statistical tests, a confidence level of 95% was considered. The soluble solids content increased by 28% as a function of the fertigation doses. The electromagnetically treated water reduced the number of fruits with blossom-end rot by 35% (p < 0.05). Overall, electromagnetic water improved the physicochemical quality parameters and the nutritional status of tomato fruits. Thus, this study demonstrated that green technology could leverage tomato fruit production and quality.

DESEMPENHO AGRONÔMICO E QUALIDADE DOS FRUTOS DE MELÃO AMARELO ADUBADO COM DOSES DE NITROGÊNIO E POTÁSSIO

ABSTRACT The objective of this study was to evaluate the assimilated contents of mineral elements, yield characteristics and fruit quality of ‘Goldex’ yellow melon fertigated with different doses of nitrogen (N) and potassium (K) in two years of cultivation in the region of Apodi Plateau-CE. The design was randomized blocks in a 4x3 factorial scheme with four N doses (0%, 50%, 100%, 150% of the recommended dose) and three K doses (0%, 100%, 150% of the recommended dose). In the shoots of the melon plant, the highest levels of N (N Fert.) and K (K Fert.) fertilization promoted an increase in the assimilated N content up to 48 DAT and a reduction in the assimilated K content at the end of the cycle (62 DAT). The maximum shoot dry mass production was 3.23 t ha−1 with a fertilization of 150 and 100 kg ha−1 of N and K, respectively. The average marketable fruit yield obtained in the two years of cultivation was 34.68 t ha−1, reaching a maximum value of 40.28 t ha−1 under 150 kg ha−1 N and K fertilization. Total soluble solids increased as a function of the increase in N Fert. and K Fert., with a maximum value of 8.07 °Brix. The models indicated that the K Fert. factor was decisive in the increase of this variable. In future studies it is necessary to increase the concentrations of the two factors in order to optimize the maximum viability of yield and °Brix.

Determination of Association of Yield Components in Tomato (Solanum lycopersicum L.)

The present investigation was conducted in Randomized Block Design with 38 genotypes (including three checks) of tomato in three replications for thirteen quantitative traits. The objectives were to assess the correlation for fruit yield and yield contributing characters. The association studies showed that fruit yield per plant had highly significant and positive correlation with marketable fruit yield per plant, average fruit weight, equatorial diameter, unmarketable fruits yield per plant and number of fruits per plant at both phenotypic and genotypic levels.

Effect of Plastic Mulch Colors on Anasa tristis (Hemiptera: Coreidae) Population Dynamics in Summer Squash, Cucurbita pepo (Cucurbitales: Cucurbitaceae).

The squash bug, Anasa tristis (De Geer), is a serious pest of cucurbit crops across the United States, especially within summer squash (Cucurbita pepo L.) systems. Using their piercing sucking mouthparts, squash bugs feed on both leaf tissue and fruits, often leading to leaf necrosis, marketable fruit loss, and even plant death. To date, the relationship between squash bug presence and plasticulture has not been adequately investigated. This 2-yr study evaluated the effects of white, black, and reflective plastic mulch colors on the occurrence of all squash bug life stages and marketable zucchini yield in Virginia. In both years, A. tristis adults and egg masses were more numerous on zucchini plants grown in white and reflective plastic mulch compared to bare ground plants. Greater nymphal densities and marketable fruit yield were observed in certain plastic mulch treatments versus the bare ground treatment, yet these differences were not consistent in both years. Contrary to the repellency effects reflective mulches have on other cucurbit insect pests, our research suggests that reflective and other plastic mulch colors can negatively impact squash bug management, especially in regions with high A. tristis pressure. Our study offers new insights for cucurbit growers to use when considering whether they should implement plasticulture in their growing systems.