Yield Of Papaya Research Articles

Influence of Biofertigation and Crude Edible Oils Application on Yield Attributing Characters and Yield of Papaya (Carica papaya L.) cv. Red Lady

Various organic substances have demonstrated effectiveness in sustaining soil and plant health, thereby enhancing growth, yield, and quality across different crops. The experiment was carried out to know the influence of biofertigation and crude edible oils application on yield attributing characters and yield of papaya (Carica Papaya L.) cv. Red Lady at Department of Fruit Science, Dr. YSRHU-College of Horticulture, Venkataramanannagudem, West Godavari district of Andhra Pradesh during 2021-22 and 2022-23. The experiment was laid out in a Factorial RBD with three replications consisted of two factors viz., biofertilizers at three levels (B1: 5 ml each of NFB + PSB + KRB; B2: 2.5 ml each of NFB + PSB + KRB; B3: Without biofertilizer) and crude edible oil at five levels (C1: Ground nut oil @0.5%; C2: Castor oil @0.5%; C3: Mustard oil @0.5%; C4: Ground nut oil + Castor oil + Mustard oil @0.5%; C5: No crude oil spray) with fifteen treatment combinations. Among the treatments studied, the results revealed that minimum days to first flowering, fruit initiation height, days to first harvest, maximum number of fruits per plant, fruit length, fruit girth, average fruit weight, fruit yield per plant and fruit yield hectare were registered in the plants applied with 5 ml each of biofertilizers NFB+ PSB + KRB along with ground nut oil + castor oil + mustard oil @0.5% (B1C4).

Effect of organic manures and bio-fertilizers on growth and yield of papaya (Carica papaya L.) cv. Red Lady

An experiment was conducted at Experimental unit (Pilikothi) Department of Horticulture, Tilak Dhari Post Graduate College, Jaunpur during 2019-20 to assess the effect of organic manures and bio-fertilizers on growth and yield of papaya (Carica papaya L.) cv. Red Lady. The saplings of papaya were transplanted on 15th October with a spacing of 1.8 m×1.8 m. The experiment was laid out in Randomized Block Design with eleven treatments replicated thrice. Result indicated that the maximum plant height (260.48 cm), stem girth (46.52 cm), petiole length (80.38 cm), leaf area (1406.15 cm2) and plant spread (193.32 cm) was recorded with T9 (Neem cake + Azotobacter + PSB) application followed by plant height (255.28 cm), stem girth (42.24 cm), petiole length (76.15 cm), leaf area (1388.22 cm2), plant spread (189.49 cm) with T7 (Vermicompost + Azotobacter + PSB) and minimum in control. Observations recorded on yield and yield contributing characters revealed that the fruit length (35.48 cm), fruit diameter (16.22 cm), fruit volume (1272.45 cc), fruit weight (1274.82 gm), fruit yield per plant (58.4 kg), fruit yield per plot (467.2 kg), fruit yield per hectare (72.6 q) was recorded maximum with T10 (Farm yard manure + Vermicompost +Poultry manure + Neem Cake + Azotobacter + PSB) and the minimum values of these characters were recorded T11 under control.

Insecticidal Activity of Selected Plant-Derived Essential Oils against Papaya Mealybug (Paracoccus marginatus)

The current study aims to assess the effectiveness of three essential oils derived from neem, citrus, and garlic against papaya mealybug. Papaya seedlings were transplanted in the field in a completely randomized block design with eight treatments with four replications. The treatments included neem, citrus, and garlic oils in combination with isopropyl alcohol or paraffin oil as an adjuvant. Results from this study showed that neem oil at 1.5% + 0.2% isopropyl alcohol was effective against papaya mealybug by 93.0% equivalent to the positive control (imidacloprid) (99.4%), followed by citrus oil at 1.5% + isopropyl alcohol (76.3%) and citrus oil at 1.5% + paraffin oil (68.8%), compared with the untreated 0.01%. Similarly, application of the plant-derived essential oils and adjuvants resulted in positive effects on plant parameters (plant height, number of leaves, flower buds, number of fruits, and fruit weight) and, hence, increased papaya yield from an average of 38 to 90 fruits/plant at first harvest. The finding from this study provides an understanding of papaya farmers towards the use of natural plant products, particularly plant-derived essential oils, and their benefits, which may encourage farmers to increase papaya production and minimize the usage of synthetic pesticides to avoid pest resistance.

Effect of Washing and Non-washing of Seeds on Growth of Papaya Seedlings (Carica papaya L.) cv. Pusa Nanha

The present experiment was carried out to investigate the response of washing and non- washing of seeds on growth of papaya seedling at the CRC Farm, ITM University, Gwalior (M.P.). The experiment was set up in the Randomized Block Design using 4 media with or without washing of seeds with tap water comprising 12 treatments combinations (viz., controlled (soil + water), vermiwash (50%) + wood dust, vermiwash (50%) + cocopeat, vermiwash (50%) + pond soil, cow-urine (50%) + wood dust, cow-urine (50%) + cocopeat, cow-urine (50%) + pond soil, vermiwash (100%) + wood dust, vermiwash (100%) + cocopeat, vermiwash (100%) + pond soil, cow-urine (100%) + wood dust, cow-urine (100%) + cocopeat, cow-urine (100%) + pond soil which were replicated thrice. For experimental purpose, freshly ripe fruits of papaya were purchased from the papaya-growing farmer of IARI, New Delhi and seeds were sown in the poly bag (4x24 inch sized). The results indicated that the application of application of Vermiwash (100%) + pond soil recorded maximum height of seedling (cm), number of leaves per seedling, stem diameter (cm), leaf area (158.41 cm2), fresh weight of seedling (8.49g), dry weight of seedling (1.17 g), dry weight of shoot (0.334g), dry weight of root (0.779), root/shoot ratio (2.34) as compared to without washing of seeds and other rooting media. Thus, application of Vermiwash (100%) + pond soil was found to the best treatment among all the treatments and it gave the maximum growth attributes which will inturn improve the yield of papaya.

Water requirements of banana and papaya under different water table depths and soil types in the Lower Indus Basin of Pakistan

AbstractThe water requirements of banana and papaya, the two most important fruit crops of Pakistan, are not known because farmers continue to apply water even if the crop does not need it. In this study, the evapotranspiration (ET), groundwater contribution (GW) and crop coefficient (Kc) values of banana (1995–1999) and papaya (2013–2016) were determined under different water table depths (WTDs) and soil types using drainage‐type lysimeters. The WTDs were maintained at 1.50, 2.00 and 2.50 m from the ground surface by means of Mariotte bottles. The banana ET during the first year was between 1653 and 1992 mm with a GW contribution of 11–20%, whereas during the second to fifth years, it was between 2430 and 3023 mm with a GW contribution of 10–16%. The banana yield was in the range of 58,638–79,780 kg ha−1, and the water use efficiency (WUE) was between 2.65 and 3.31 kg m−3. The papaya ET was between 1478 and 1766 mm with a GW contribution of 7–18% at 1.50–2.50 m WTDs. The papaya yield was in the range of 61,184–83,004 kg ha−1 with a WUE of 4.13–4.70 kg m−3. Therefore, GW contribution is an important component of the water balance under shallow water table conditions and should be considered when devising irrigation scheduling for banana and papaya crops.

Effect of Irrigation Levels and Straw Mulching on Yield and Water Use Efficiency of Papaya under Drip Irrigation System

Papaya (Carica papaya L.) is a significant fruit crop cultivated worldwide in tropical and subtropical regions. However, its cultivation is often constrained by limited water availability and soil moisture stress, which may significantly affect its yield and quality. This study aimed to explore the effects of irrigation levels and straw mulch on the growth and yield of papaya under a drip irrigation system. The experiment encompassed six treatments: three different irrigation levels (100%, 75%, and 50% of crop water requirement) and two mulch levels (straw mulching and no mulch). The effect of mulch levels on plant growth, yield, and water use efficiency was statistically significant. The results revealed that applying 100% of crop water requirement along with straw mulch resulted in the maximum plant height, stem girth, crown diameter, and yield compared to the no mulch treatment. The study also evaluated irrigation water use efficiency, an essential aspect of sustainable farming practices. The results indicated that the maximum irrigation water use efficiency (58.47 kg m-3) was recorded when 50% of the crop water requirement was met alongside straw mulch. Conversely, the minimum irrigation water use efficiency was observed when 100% of the crop water requirement was completed without any mulch under the drip irrigation system.

TIPOLOGÍA DE PRODUCTORES Y DIFERENCIACIÓN DE LOS AGROECOSISTEMAS CON PAPAYA (Carica papaya L.) EN OAXACA, MÉXICO

<p><strong>Background:</strong> The Costa region is the main papaya (<em>Carica papaya</em> L.) producing area in the state of Oaxaca. However, there are no studies that document the potentialities, limitations, and development of the productive and commercial process of this crop with a comprehensive approach. <strong>Objective:</strong> To characterize papaya producers and their agroecosystems in the Costa region of the state of Oaxaca, Mexico; and determine a representative typology, based on their socioeconomic, productive, technological and commercial characteristics, using multivariate analysis techniques. <strong>Methodology:</strong> A questionnaire was applied through a probabilistic sampling to 89 papaya producers from seven municipalities in the Costa region of the state of Oaxaca, which included quantitative and qualitative variables, classified into indicators: i) social: ii) physical, iii) productive, iv) economic, v) management, vi) commercialization, vii) technological. Data analysis included descriptive statistics, review and selection of variables, factor analysis by the principal components method, identification of clusters, comparison and differentiation of defined groups, and discriminant analysis. <strong>Results:</strong> Through factorial analysis, two factors were selected that explained 72.89% of the original variability. The first factor was related to the variables economic income from the sale of papaya, profitability factor and papaya yield; while the second factor was explained by the experience of the producer. The cluster analysis allowed to identify three types of papaya producers (conventional, intermediate, and businesses), which represented 62%, 28% and 10% of the total sample. The variables with the greatest discriminating power between groups were economic income from the sale of papaya, papaya yield, and the profitability factor. <strong>Implications:</strong> The defined typology suggests the need to improve the design of public policies and promptly reorient them based on the heterogeneity among papaya producers in the study region. <strong>Conclusions: </strong>The papaya producers in the study sample are relatively young, have an intermediate level of schooling and seniority in the activity; those that make up Group 3 (businesses) stand out for having higher crop yields and better marketing channels. Papaya agroecosystems differ mainly by cultivated area, production yield, economic income and production costs.<strong></strong></p>

Studies on the Effect of Split Application of NPK fertilizers on Growth and Yield of Papaya under Central Dry Zone of Karnataka

A field experiment was conducted at Eswargere village, Hiriyur taluk, Chitradurga district during the year 2020-2021 to assess the effects of split application of nitrogen, phosphorus, and potassium (NPK) fertilizer on papaya growth and yield, and the experiment was set up in Randomized Complete Block Design. The treatments include seven treatments comprising varying rates (75, 100 and 125% recommended dose of fertilizers) and time of application (Bimonthly and monthly intervals). Among growth attributes plant height (186.70 cm), stem girth (46.38) was recorded highest in 125% RDF through split application. In yield attributes maximum fruit length (23.54 cm) circumference (44.75 cm), volume (1711.07 cc) firmness (7.43 kg/cm2), total yield (138.83 t/ha) and lowest cavity index (14.84) were also observed in 125% RDF through split. Applying of 125% RDF through split at different growth stages (187.5:156.25:125 N: P2O5: K2O g/plant) in vegetative stage of 4 months, (62.5:125:187.5 N: P2O5: K2O g/plant) in flowering to fruit set stage of 2 months, (62.5:31.25:312.5 N: P2O5: K2O g/plant) in fruit development stage of 3 months at monthly interval showed to be better for fetching maximum plant growth and yield of papaya fruits.

Pemanfaatan Buah Pepaya Sebagai Upaya Peningkatan Pendapatan UMKM Anggota Kelompok Wanita Tani (KWT)

This service invites people who still lack understanding in utilizing the abundant papaya yield. Armed with these problems, the purpose of this community service is to innovate and assist in the use of papaya fruit as an effort to increase the income of MSME Members of the Women Farmers Group (KWT) in Tiyuh Makarti, Tumijajar sub-district, West Tulang Bawang Regency. The method used in this service is the ABCD method as a means of community service approach with an orientation so that people have the power to recognize and utilize all the strengths and assets they have. The results of this dedication are crispy papaya products with attractive packaging and can be traded. Apart from that, this crispy papaya product can also be used as a souvenir so that it can increase the economic income of the community in general and KWT in particular.

Effect of Calcium Nitrate and Calcium Carbonate on Plant Growth, Fruit Quality and Yield of Papaya Cv. Red Lady

A field experiment was performed to study the effects of foliar applications of CaCO3 and Ca(NO3)2 on growth, quality, yield, and shelf life of papaya (Carica papaya) Cv. Red lady. Calcium (Ca) is one of the major plant nutrients which affects significantly the formation of the cell walls and cell membranes and also enables the production of biomass with proper plant growth and function. In the current experiment, papaya seedlings were well established in the orchard, well-irrigated with standardized nutrient solutions with all required inter-culture activities. Four different pre-harvest foliar application sprays were provided with two varying sources of Ca (CaCO3 and Ca(NO3)2) at three concentrations of each with CaCO3 (2%, 1%, 0.5%) Ca(NO3)2 (2%, 3%, 4%) at different stages of growth like flowering stage, fruit set stage, pre-harvest stage. The study revealed that foliar spray of above mentioned concentrations showed a profound improvement in vegetative growth of plants in terms of their height and diameter as compared to the plants in control treatment and also affected the fruit quality of papaya fruit.

Evaluation of Intercropped Papaya with Banana on Growth, Fruit, and Nutrient Status

Papaya cultivators in northeast Thailand deal with dry conditions that dramatically affect growth, yield, and fruit quality. The use of intercropping fruit crops, especially banana, should improve papaya production. This study evaluated intercropping papaya and banana in terms of papaya growth, fruit quality, and nutrient content. Experiments were conducted at the Fruit Tree Experimental Field, Faculty of Agriculture, Khon Kaen University between January 2019 and July 2020. The mono-papaya and intercropped papaya with banana used 3 × 2 m spacing, and the intercropped papaya used 1 row of banana with 3 rows of papaya. Plant growth was analyzed between the 5th and 19th month post-transplantation, while fruit yield and nutrient status were evaluated between the 14th and 19th month after transplantation. Plant height, number of leaves, and girth were not different between mono- and intercropped papaya. All plant growth patterns were sigmoidal, reaching stable growth rates between the 15th and 19th month after transplantation. Fruit numbers were not significantly different, but banana-intercropping with papaya increased papaya yield through fruit length and pulp thickness. Nutrient levels in all plant parts were not significantly different. In addition, nutrient analysis identified that papaya fruit extracted N, K, and B at higher levels than other parts, while P and Ca were the highest removed by the stem.

Comparative transcriptomics and genomic analyses reveal differential gene expression related to Colletotrichum brevisporum resistance in papaya (Carica papaya L.).

Colletotrichum brevisporum is an important causal pathogen of anthracnose that seriously affects the fruit quality and yield of papaya (Carica papaya L.). Although many genes and biological processes involved in anthracnose resistance have been reported in other species, the molecular mechanisms involved in the response or resistance to anthracnose in post-harvest papaya fruits remain unclear. In this study, we compared transcriptome changes in the post-harvest fruits of the anthracnose-susceptible papaya cultivar Y61 and the anthracnose-resistant cultivar G20 following C. brevisporum inoculation. More differentially expressed genes (DEGs) and differentially expressed long non-coding RNAs (DElnRNAs) were identified in G20 than in Y61, especially at 24h post-inoculation (hpi), suggesting a prompt activation of defense responses in G20 in the first 24h after C. brevisporum inoculation. These DEGs were mainly enriched in plant-pathogen interaction, phenylpropanoid biosynthesis/metabolism, and peroxisome and flavonoid biosynthesis pathways in both cultivars. However, in the first 24 hpi, the number of DEGs related to anthracnose resistance was greater in G20 than in Y61, and changes in their expression levels were faster in G20 than in Y61. We also identified a candidate anthracnose-resistant gene cluster, which consisted of 12 genes, 11 in G20 and Y61, in response to C. brevisporum inoculation. Moreover, 529 resistance gene analogs were identified in papaya genome, most of which responded to C. brevisporum inoculation and were genetically different between papaya cultivars and wild-type populations. The total expression dose of the resistance gene analogs may help papaya resist C. brevisporum infection. This study revealed the mechanisms underlying different anthracnose resistance between the anthracnose-resistant and anthracnose-susceptible cultivars based on gene expression, and identified some potential anthracnose resistance-related candidate genes/major regulatory factors. Our findings provided potential targets for developing novel genetic strategies to overcome anthracnose in papaya.

Challenge of transition: the history of a case study involving tropical fruits polyculture stimulated by humic acids and plant-growth promoting bacteria

BackgroundInnovative technologies are required in agricultural production to eliminate the environmental risk generated by the intensive use of fertilizers and pesticides. Soil organic matter is a keystone for the transition towards sustainable production. However, it is not an easy task to increase soil organic matter in highly weathered soils without considerable resources and energy. Here, we highlighted the role of biological inputs in plant adaptation to low fertility and water scarcity. The direct use of humic acids and plant growth-promoting bacteria on plants can modify the root architecture systems, including surface area and roots length, thus allowing greater soil exploration.Material and methodsWithin a socio-historical perspective of concepts and research methods, a case study is presented on the effects of humic acids applied together with plant-growth promoting bacteria, as an efficient tool for supporting the transition to more suitable production system. We implemented this natural ecological approach onto a polyculture system with different tropical fruits (banana, passion fruit, papaya and pineapple) and evaluated crop yields.ResultsWe observed increases of around 50 and 90% in banana and papaya yield, respectively, and 25% in passion fruit productions, with significantly greater yields maintained over four production cycles. No effect was observed in ananas production probably due to the large shading level in the area.ConclusionThe biostimulant formulated with endophytic diazotrophic bacteria and humic acids represents a low-cost technology that enhances crop yields and can play an important role in promoting a transition process towards sustainable agriculture.Graphical

Characterization of Farmer’s knowledge and management practices of papaya mealybug Paracoccus magnatus (Hemiptera: Pseudococcidae) in Tanzania

Papaya mealybug (PMB) is a serious insect pest for papaya production in Sub-Saharan Africa, limiting production potential in farming communities. We did a household survey to evaluate the Characteristics of farmers' knowledge, challenges, and current (PMB) control practices in four papaya growing regions of Tanzania namely, Tanga, Dodoma, Pwani, and Katavi involving 100 papaya farmers. The study found that 96% of farmers reported PMB, as a major challenge in papaya production. Very few (0.8%) of the farmers were knowledgeable on insect pest identification. Chemical pesticides were the only option for PMB control, and 43.0% of farmers were able to access and apply. We also found that 36.4% of the farmers were aware of the adverse effects of chemical pesticides. Furthermore, the study observed that 0.3% of farmers use botanical pesticides. Additionally, the study observed that 44.1% of farmers use control measures against PMB, the remaining 55.9% did not practice any control measure, thus leading to low papaya yields observed in the study regions. Our findings provide insights to farmers into the use of plant-based pesticides, mainly plant essential oils, and its benefits that may promote farmers' attitudes towards increasing papaya yield and reducing chemical pesticide use to avoid pest resistance.

Impact of soil water regimes and partial root-zone drying in field-grown papaya in semi-arid conditions

This study aimed to evaluate in the papaya Tainung genotype, the effects of partial root-zone drying (PRD) technique on soil water regimes by using different frequencies of shifting irrigation-side of plant row and the effects of PRD technique on (1) crop agronomic performance, (2) titratable fruit acidity (TA), (3) total soluble solids (TSS), and TSS/TA ratio. Also, we analyze the spatial dynamic of papaya condition using normalized difference vegetation index (NDVI) from different satellite images. The study was conducted in the semi-arid region of Bahia (BA) and Minas Gerais (MG), Brazil. The combination of 100% (Full irrigation—FU), 50%, and 35% in the irrigation depth (WID) and frequencies of shifting plant-row side irrigation of 0 (Fixed Irrigation—FX), 7, 14, and 21 days were applied. Nine treatments were studied in BA and five in MG. The water available in the soil was reduced to 44% for frequencies of shifting plant-row side irrigation of 7 days, 50% for 14 days, and 85% for 21 days, compared to the soil water availability at field capacity. Partial water deficit in the soil through the PRD technique did not significantly reduce the total root length, effective root depth, and root effective horizontal distance of the papaya Tainung genotype. However, PRD treatments showed leaf abscission, which resulted in reduced leaf area and NDVI values, especially in the MG experiment. Papaya yield and fruit quality were not affected. However, except for PRD 21 35%, irrigation water depth reduced to 50 and 35% under PRD increased crop water productivity (CWP) in papaya plants. Thus, the PRD technique may save 35% of WID using the alternation of lateral shift irrigation of crop row every 7 days under water scarcity in semi-arid regions. The NDVI index was important to compare the papaya canopy vigor between the experimental areas studied. We also confirmed the potential of NDVI to monitor the vigor of papaya canopy, since we could notice the sensibility of NDVI to identify water stress in papaya in higher vapor pressure deficit (VPD) conditions occurred in October 2016 and January 2017 in Bom Jesus da Lapa-BA. Therefore, the PRD strategy can be a useful tool to save water in papaya cultivation under semi-arid conditions.

Effect of organic manure and bio-fertilizer on growth and yield of papaya (Carica papaya L.) Cv. red lady

The present investigation was carried out at Krishi Vigyan Kendra, Balod, Indira gandhi Agricultural University, Raipur, Chhattisgarh during the year 2018 -19 and 2019-20, respectively and was laid out in Randomized Block Design (RBD), the experiment comprising ten treatments and three replications. 200:200:200 gm NPK /plant were applied as per recommendation in all ten treatments combinations involving different organic manures and biofertilizers. The results revealed that the growth parameters viz., plant height (184 cm), were significantly maximum in papaya plant receiving with treatments( RDF+ FYM@ 10 kg /plant +Azospirillum@ 10 gm / plant + PSB @10 gm / plant ) Whereas stem girth (48.47cm), number of leaves(48.13), total leaf area (9.77m2) and length of petiole (70.57cm) were highest with the treatment RDF+ FYM@ 10 kg /plant +Azospirillum@ 10 gm / plant + PSB @10 gm / plant(T8) and treatment ( RDF +Azospirillum@ 10 gm / plant + PSB @ 10 gm / plant) found at par for all the growth parameters results. Number of fruits per plant(34.17), average fruit weight (1.15kg), fruit yield per plant (38.95 kg) and per ha(116.86), fruit length (22.58cm) and pulp weight per fruit (845.47gm) were found significant in papaya plants supplied with RDF +Azospirillum@ 10 gm / plant + PSB @ 10 gm / plant and fruit girth (23.15cm), fruit volume 894.17(cc) and seed weight per fruit(84.96) were found significant with treatment RDF+ FYM@ 10 kg /plant +Azospirillum@ 10 gm / plant + PSB @10 gm / plant. Likewise poor performance was observed in control for all parameters.

Bioregulators Induced Modulation of Leaf Physiological Attributes and Severity of Papaya Ring Spot Viral Disease Symptom expression in Papaya

The present study aimed to evaluate the influence of bioregulators on physiological attributes and yield components of TNAU Papaya CO. 8 variety during 2017 - 2018. The study involved two factors viz., growth retardants as factor I and stress tolerance promoting bioregulators as factor II. The treatments involving growth retardants (Factor I) were water spray (G1) as control, 250 ppm of pro hexadione calcium (G2), 500 ppm of mepiquat chloride (G3) and 500 ppm of chlormequat chloride (G4). Similarly, the stress tolerance promoting bioregulators (Factor II) comprised of water spray as control (S1), 100 ppm of methyl jasmonate (S2), 100 ppm of salicylic acid (S3) and 0.6 g/ L of strobilurins (S4). The bioregulators were applied as foliar spray at the fourth and eighth months after transplanting. Initially, growth retardants were sprayed and one week after that, the stress tolerance promoting bioregulators were sprayed. Observations were recorded on number of leaves, leaf area index, leaf gas exchange parameters, papaya ring spot virusdisease incidence and yield components. Among the treatments, higher number of leaves (52.03) were observed in the combination involving 250 ppm of prohexadione calcium and 100 ppm of salicylic acid (G2S3) and leaf area index (2.73) was highly influenced by 500 ppm of chlormequat chloride and 100 ppm of salicylic acid (G4S3). Leaf gas exchange parameters were found to be superior with 250 ppm of prohexadione calcium and 100 ppm of salicylic acid treatment (net photosynthetic rate - 16.46 µmol cm-2 s-1, stomatal conductance - 0.51 mol m-2s-1, transpiration rate - 7.58 mmol m-2s-1) as compared to control. Significant differences were also observed among the treatments for yield and yield components. The fruit yield was significantly improved by the treatment involving 500 ppm of mepiquat chloride and 100 ppm of salicylic acid (G3S3 - 61.76 kg plant-1), indicating the possibility for enhancing papaya yield under field conditions where PRSV is prevalent.

Crop losses and economic impact associated with papaya mealybug (Paracoccus marginatus) infestation in Kenya

This study quantified crop losses and economic impacts associated with papaya mealybug (Paracoccus marginatus) infestation in Kenya and identified the most important predictors of papaya tree (Carica papaya L.) yield losses through a household survey of 404 farmers. At least 95% male and 88% female respondents correctly identified papaya mealybug. Papaya was the most affected crop by the pest, with 73% of the respondents indicating that a major part (>60%) of their trees was affected. The estimated papaya yield losses due to papaya mealybug were 57%, with an associated annual economic loss of US$3,009 per ha at the farm level and US$29.8 million at the national level. Regression analysis showed significant yield-reducing effects with high infestation levels of papaya mealybug, use of local varieties, and use of indigenous pest control practices. Economic losses differed significantly by county, with the highest losses reported in Mombasa. Male farmers reported higher losses than their female counterparts. Findings highlight the need for location and gender-specific information on pest management for effectiveness in controlling papaya mealybug.

Standardization of Spacing and Soil Volume Wetting for Drip Irrigationin Papaya (Carica papaya L.)

Field experiments in two crops of papaya were conducted at ICAR-Indian Institute of Horticultural Research for four years during 2016-19 to standardise spacing with optimum soil volume wetting for drip irrigation. Narrowing the plant rows drastically reduced the plant height while leaf production affected significantly due to reduction in intra row spacing. The height at first fruiting was significantly lower with a spacing of 1.8 m x 1.5 m (56.4 cm) significantly differing from both 1.5 m x 1.5 m (60.9 cm) or 1.8 m x 1.8 m (66.8 cm). Significantly higher mean fruit yield (42.2 t/ha) was recorded with the spacing of 1.5 m x 1.5m as compared to either 1.8m x 1.5m (23.4 t/ha) or 1.8m x 1.8m (22.1 t/ha). Significantly higher water use efficiency (71.3 kg/ha.mm) was recorded in papaya by following closer spacing of 1.5 m x 1.5 m. Among the interactions, higher papaya yield (48.0 t/ha) was recorded with normal drip irrigation (80% soil volume wetting) under closer spacing (1.5 m. x 1.5 m). Further, higher water use efficiency (129 kg/ha. mm) could be obtained by scheduling the irrigation at 30% soil volume wetting especially by planting at 1.5 m. x 1.5 m. spacing suggesting its suitability for water scarcity areas.

Standardization of Spacing and Soil Volume Wetting for Drip Irrigationin Papaya (Carica papaya L.)

Field experiments in two crops of papaya were conducted at ICAR-Indian Institute of Horticultural Research for four years during 2016-19 to standardise spacing with optimum soil volume wetting for drip irrigation. Narrowing the plant rows drastically reduced the plant height while leaf production affected significantly due to reduction in intra row spacing. The height at first fruiting was significantly lower with a spacing of 1.8 m x 1.5 m (56.4 cm) significantly differing from both 1.5 m x 1.5 m (60.9 cm) or 1.8 m x 1.8 m (66.8 cm). Significantly higher mean fruit yield (42.2 t/ha) was recorded with the spacing of 1.5 m x 1.5m as compared to either 1.8m x 1.5m (23.4 t/ha) or 1.8m x 1.8m (22.1 t/ha). Significantly higher water use efficiency (71.3 kg/ha.mm) was recorded in papaya by following closer spacing of 1.5 m x 1.5 m. Among the interactions, higher papaya yield (48.0 t/ha) was recorded with normal drip irrigation (80% soil volume wetting) under closer spacing (1.5 m. x 1.5 m). Further, higher water use efficiency (129 kg/ha. mm) could be obtained by scheduling the irrigation at 30% soil volume wetting especially by planting at 1.5 m. x 1.5 m. spacing suggesting its suitability for water scarcity areas.