Coorg Honey Dew Research Articles

Comparative Study of the Agronomic and Organoleptic Performances of Some Varieties of Papaya (Carica papaya L.) Grown Outdoors and in Polyhouse in Kerala (India)

The present study was undertaken with the objective to evaluate the performance of papaya varieties under two growing conditions (open and polyhouse) in terms of yield and quality attributes. The study was conducted in Fruits Crops Research Station, Kerala Agricultural University, Thrissur during 2022-2023. The seedlings of seven papaya varieties, CO-3, CO-7, Arka Surya, Arka Prabhath, Coorg Honey Dew, Pusa Delicious and Red Lady were planted under both open field and polyhouse condition at a spacing of 2 m x 2 m in CRD with five plants per variety. Compared to the plants grown in open field, the plants grown under polyhouse showed an early flowering (75.68 days), minimum fruit cavity index (15.47 %), zero disease incidence to PRSV, maximum TSS (13. 67 ˚B) and total sugars (11.26 %) in CO-7 while maximum fruit length (18.84 cm) and fruit mass (2605.34g) were observed in CO 7. It was also observed that CO-7 grown under polyhouse showed an increased yield (55.20 kg/plant) as compared to the plants under open condition. Hence, it can be concluded that CO-7 can be successfully cultivated under polyhouse condition in Kerala with good yield and quality.

Evolution of Induce and Physical Mutagen on Vegetative Traits of Papaya (Carica papaya L.)

The experiment was conducted on Horticultural Research Centre of Sardar Vallabhbhai Patel University of Agriculture and Technology, located in Meerut, Uttar Pradesh. The experiment was laid out in RBD design and data was recorded on different growth trait of papaya. Two variety of papaya Arka surya and Coorg honey dew, the seed of papaya was treated with Gamma and EMS mutagen and sown in field for evolution. The treatment detail of the experiment was T1, 5 Gy, T2, 10 Gy, T3, 15 Gy, T4, 0.25% EMS, T5, 0.50% EMS, T6, 0.75% EMS, T7, 5 Gy+0.25% EMS, T8, 10 Gy+0.50% EMS, and T9, 15 Gy+0.75% EMS. Finally, on the basis of result recorded that in both year days taken to seed germination and stem girth(cm), 10GR better performance over all treatment, while in number of leaves at flowering and petiole length (cm), 5GR better performance over all treatment. Whereas, In EMS and (Gamma rays + EMS), 0.25% EMS and 5G+0.25%EMS perform better result for petiole length and number of leaves at flowering while for days taken to seed germination and stem girth, 0.50%EMS and 10G+0.50%EMS perform better result.

A randomized, open-label, controlled, parallel-group comparative study of two varieties of Carica papaya leaves in dengue-induced thrombocytopenia

Background: Dengue-induced thrombocytopenia can be life-threatening. However, supportive and symptomatic treatment is the current management protocol. The leaf extract of papaya has shown promising results in improving the platelet count. There are many varieties of Carica papaya such as Washington, Honeydew, Coorg honeydew, Solo, Surya, Red lady, C0-1, CO-3, CO-5, C0-6. Aims and Objectives: The aim is to evaluate the efficacy and safety of two varieties (“Red Lady” and “Solo”) of C. papaya fresh leaf extract in patients diagnosed with dengue-induced thrombocytopenia. Materials and Methods: The study was conducted for 2 months, and 18 dengue-confirmed inpatients with thrombocytopenia (platelet count <1,50,000/μL) were enrolled. The study participants were grouped into the standard “Control” group, “Solo” group who received fresh papaya leaf extract “Solo” and “Red Lady” group who received fresh papaya leaf extract of “Red Lady.” About 30 mL of leaf extract was given thrice daily for 5 days. Results: The mean change from the baseline value of platelets was found to be 59,168/µL for the control group and 57,000/µL for Red Lady, and 93,167/µL for the solo group. The study showed a positive trend with improvement in platelet count in “Solo” Variety group when compared to “Red Lady” group and the control group. The safety results showed that both the papaya leaf extracts have a favorable safety profile. Conclusion: There was an improvement in platelet count in “Solo” variety group when compared to “Red Lady” and the control group. However, the results were not statistically significant. No adverse events were observed during the study.

Papaya cultivars of the world

Although the family Caricaceae has about 48 species, only Carica papaya produces edible fruits. A large number of cultivars are grown in different papaya-producing countries. The number of cultivars is quite large because of out-crossing in papaya, and these cannot be called cultivars. In India, more than 30 cultivars and hybrids are grown in different states, of which ‘Coorg Honey Dew’, ‘Washington’, ‘Ranchi’, ‘Taiwan’ hybrids, ‘Solo’, CO cultivars (‘CO1’, ‘CO2’, ‘CO3’, ‘CO4’, ‘CO5’, ‘CO6’), ‘Pusa Majesty’ and ‘Pusa Delicious’ are popular. Solo cultivars ‘Kapoho’, ‘Sunrise’, ‘Sunset’ and ‘Waimanalo’ are grown in Hawaii, USA. In the Philippines, ‘Cavity Special’, ‘Sunrise Solo’, ‘Waimanalo’ and ‘Sinta’ (hybrid) are the cultivars. The main cultivar of Taiwan is ‘Tainung 2’, which occupies more than 90% of papaya in Taiwan. There are a few other cultivars, including ‘Sunrise’ (5%), ‘Red Lady’ (4%) and newly released cultivar ‘Tainung 10-OrangeBaby’ (1%). In Vietnam, the most popular cultivar is ‘Dai Loan Tim’, the main purple Taiwan cultivar. The other cultivar grown is ‘Sieu Lun Cao San’, ‘Tainung 01’ occupies 99% of Formosa papaya and 1.0% of Bela Vista in Brazil. Among the Solo group of papaya, ‘Sunrise Solo BS’ is grown for the internal market and ‘Golden THB’ for the export market in Brazil. Australian papaya growers mainly grow red papaya, ‘RB1’, ‘RB2’, and ‘Skybury’, as commercial cultivars, and ‘IB’ and ‘Hybrid 13’ for yellow-fleshed papaya. ‘Khaek Dam’, ‘Khaek Nuan’ and ‘Dampit’ are popular in Indonesia. Mexican cultivars are ‘Mexican Red’, ‘Caribbean Red’, ‘Maradol’, ‘Royal’, ‘Star Papayas’, ‘Singapore Pink’, ‘Higgins’ and some genetically modified cultivars. The mayor cultivars of Malaysia are ‘Batu Arang’, ‘Sitiawan’ and ‘Subang 6’. Other cultivars developed and used as dessert fruit for export are ‘Eksotica’, ‘Eksotica II’ and ‘Sekaki’. In South Africa, ‘Hortus Gold’, ‘Honey Gold’ and ‘Kaapmuiden’ are the major cultivars grown. Thailand growers prefer hermaphrodite red-fleshed cultivars ‘Sai-nampueng’, ‘Khaek Dam’ and ‘Kheg Nuan’. In greenhouse cultivation at Okinawa, Japan, cultivars including ‘Solo’, ‘BH-65’, ‘Tainung 1’, ‘Tainung 2’, ‘Tainung 5’, ‘Maradol’, and ‘Wonder Flare’ are cultivated. This paper will discuss the characters of papaya cultivars growing in different countries of the world.

Field response of papaya (Carica papaya L. cv. Coorg Honey Dew) to inoculation with arbuscular mycorrhizal fungi at different levels of phosphorus

SummaryPapaya (Carica papaya L.) cv. Coorg Honey Dew is one of the most popular cultivars grown in Southern India, but it requires high doses of inorganic phosphorus (P) fertilisation for growth. Arbuscular mycorrhizal fungi (AMF) are known to improve plant growth and nutrient uptake, especially the uptake of P and micronutrients. As papaya plants respond well to high levels of P, inoculation with AMF was studied to see if AMF could fulfill the requirement for P in plants grown under field conditions. Papaya seedlings (n = 36 per AMF) were colonised separately, in polybags, for 45 d by two species of AMF, Glomus mosseae and G. fasciculatum. Seedlings were then transplanted to the field, with uninoculated seedlings as controls, in a replicated randomised block design. Three levels of P were applied [50, 75, or 100% of the recommended dose (240 g plant–1 year–1) of P fertiliser, as super-phosphate]. Plants were studied for root colonisation by AMF, for growth parameters, and for leaf nutrient contents (especially, P, Zn, and Cu). Acidic and alkaline phosphatase activities in the roots of AMF-colonised plants were recorded as these enzymes are involved in the mobilisation of P. The yields of plants up to 18 months-old, and fruit quality, measured by total soluble solids contents (TSSC) and β-carotene contents, were recorded. AMF-inoculated plants performed better than uninoculated control plants at all levels of P applied. G. mosseae was more effective at improving plant growth, fruit yield, and P and Zn contents than G. fasciculatum at the 75% and 50% P-levels. Cu contents increased at all P-levels in G. fasciculatum-colonised plants. Total soluble solids contents showed marginal improvements at the 75% P level with both fungi. β-carotene contents increased significantly in G. mosseae-colonised plants at the 50% and 75% P-levels, and in G. fasciculatum-colonised plants at the 75% P-level. The feasibility of applying on-farm produced AMF inoculum to improve papaya cultivation and to save 25% of the P applied during papaya cultivation is discussed.

Evaluation of arbuscular mycorrhiza and other biocontrol agents against Phytophthora parasitica var. nicotianae infecting papaya ( Carica papaya cv. Surya) and enumeration of pathogen population using immunotechniques

Root rot of papaya, caused by Phytophthora parasitica var . nicotianae, is the most widespread and important disease of papaya and is particularly damaging to many papaya varieties popular in southern India, such as Coorg Honey Dew and Surya. The objective of this study was to evaluate biocontrol agents (BCAs) under controlled and field conditions for their efficacy against Phytophthora infecting papaya cv. Surya and to detect and quantify the reduction in the pathogen population by immunological techniques. Glomus mosseae, Trichoderma harzianum and Pseudomonas fluorescens were inoculated at the time of planting in the nursery and at the time of transplanting in single, dual and tripartite combinations allowing colonization up to 90 days. Plants were challenged thereafter with Phytophthora inoculum multiplied on specialized Phytophthora medium. Uninoculated plants and those inoculated with pathogen only were controls. All the BCAs in general improved plant growth and reduced severity of disease compared to uninoculated control in both pot experiments and under field conditions. Plants preinoculated with G. mosseae + T. harzianum, provided the best results when challenged with Phytophthora, with increased plant height, girth and yield and also reduced disease severity over plants not inoculated with BCAs. Studies with Phytophthora antibodies conjugated with fluorescein isothiocyanate (FITC) and enzyme-linked immunosorbent assay (ELISA) further substantiated the reduction in infection and population of Phytophthora in BCA pretreated plants. Beneficial effect of BCAs may be due to the resistance acquired by the plant and reduction in the population of the pathogen caused by their colonization.

GENETIC ANALYSIS IN PAPAYA (CARICA PAPAYA L.)

Analysis of various genetic characters in papaya was done during 2000 to 2002 in Randomized Block Design with four replications having two plants per replication. Evaluation of parental inbreds revealed that Pusa Dwarf (PD) was dwarf and low-flowering. Pusa Nanha (PN) flowered earlier, gave large fruits and maximum yield. Coorg Honey Dew (CHD) showed high fruit set and quality. Sunrise Solo (SS) was early flowering, had high TSS, total sugars, carotenoids and maximum shelf life. Among hybrids, CHD × PD was dwarf and recorded lower height to first flower. PN × CHD recorded maximum fruit set and earlier harvest. The highest yield per plant was in CHD × SS and SS × PD. On per se performance and combining ability analysis, the hybrids PD × CHD (dwarf, low-flowering, early bearing), PN × CHD (early bearing), CHD × SS (yield per plant, quality), SS × PD (yield per plant, fruit weight, fruit volume) and PN x PD (disease tolerance, yield per plant) were promising. PN had the highest number of dominant alleles for plant height, days to harvest, fruits per plant, yield per plant, fruit size, pulp percentage and total carotenoids. PD had the highest number of dominant alleles for plant girth, height to first flower, days to first flower, fruit weight, total sugars and shelf life. SS carried the highest number of dominant alleles for TSS and ascorbic acid, but the lowest number of dominant alleles for plant height, girth, days to first flower, pulp content, total sugars and shelf life. The study revealed that the hybrids PD x CHD, CHD × PD, SS × PD, CHD × SS and SS x CHD excelled all the other hybrids evaluated, based on their superior performance for various horticultural traits.

NUTRIENT AVAILABILITY AND BIOCHEMICAL PROPERTIES IN SOIL AS INFLUENCED BY ORGANIC FARMING OF PAPAYA UNDER COORG REGION OF KARNATAKA

In the recent years, papaya cultivation in India has become more popular because of its high yield and nutritive qualities. There also have emerged niche markets for organically produced fruits especially in the urban areas. Keeping in view the emerging trend, a study was conducted at Central Horticultural Experiment Station (IIHR) during 2004-07 in order to organize modules for sustainable production of organic papaya var. 'Coorg Honey Dew' under Coorg region of Karnataka, India. In this study, the effects of seven different treatments viz., recommended dose of NPK fertilizers (250:250:500 g NPK plant -1 year -1 as check (T 1 ); FYM 20 kg/plant (T 2 ), urban compost 13.5 kg/plant (T 3 ), sun hemp 25 kg/plant (T 4 ), sun hemp 40 kg/plant + rock phosphate 300 g/plant (T 5 ), neem cake 4 kg + wood ash 2.5 kg/plant (T 6 ) and rural compost 35 kg/plant (T 7 ) applied to 'Coorg Honey Dew' papaya crop were studied on nutrient availability, microbial population and enzyme activities in sandy loam soil in a field experiment laid out in randomized block design with three replications. Soil analysis after three years of study indicated no significant effect of treatments on the status of available P and K and the pH of the soil. Organic matter content in soil was significantly influenced by different treatments with the highest values recorded under T 2 and T 3 treatments. Soils under different organic modules had significantly higher microbial population (bacteria, fungi and actinomycetes) and activities of urease, phosphatase, dehydrogenase and cellulases as compared to that under recommended dose of fertilizers (T 1 ). Significant positive association between organic matter status, microbial populations and enzyme activities in soil was recorded. Application of FYM 20 kg/plant (T 2 ) was the best organic module with regard to higher microbial populations and enzyme activities in soil.

SEED GERMINATION, SEEDLING GROWTH AND VIGOUR OF PAPAYA UNDER NORTH EAST INDIAN CONDITION

Papaya (Carica papaya L.) is a popular fruit of tropics and subtropics of the world. India is in the forefront of papaya producing nations. Papaya nursery is normally raised through seeds. There are improved varieties of papaya which are being used for commercial cultivation through out the country. But none of the varieties are commercially grown in the north eastern India due to undulating topography, high rainfall, poor transport, marketing facility etc. Hence, the present study was pursued in papaya with the objective of identifying cultivars suitable to north eastern region of India with better germination percentage, seedling growth and vigour. The experiment was executed at the Horticulture division of ICAR Research Complex for NEH Region, Barapani, Meghalaya during 2001-2002 with fourteen papaya cultivars comprising varieties and hybrids of red and yellow flesh types gathered from across the world. The indigenous collections comprised cultivars from Tamil Nadu Agriculture University, Coimbatore (Co-1, Co-2, Co-3 Co-4, Co-5, Co-6, and Co-7), cultivars from G.B. Pant University of Agriculture and Technology, Pant Nagar (Pant Papaya), Indian Agriculture Research Institute, New Delhi (Pusa Dwarf) and Indian Institute of Horticultural Research, Bangalore (Coorg Honey Dew and Pink Flesh Sweet) whereas Sunrise Solo, Thailand and Washington were the other varieties from foreign sources. The seeds were soaked overnight in different concentrations of gibberellic acid (0, 50, 100, and 150 ppm) and sown in perforated polythene bags containing potting mixture. The cultivars differed significantly with respect to their 1000 seed weight, seed germination, time taken for seed germination, seedling length including seedling vigour. Soaking the seeds with GA 3 had a significant effect in improving the germination percentage of papaya cultivars. Increasing the GA 3 concentration from 0 to 100 ppm significantly improved the germination (66.17%) over the control (42.40%) and above 100 ppm the seed germination decreased. GA 3 treatment had a favorable effect in hastening the germination of papaya and the time taken for germination was maximum in untreated control (31.86 days) whereas GA 3 at 100 ppm recorded the minimum period for germination (29.73 days). GA 3 treatment had a significant effect in enhancing the seedling length and it was maximum with GA 3 100 ppm (17.38 cm) as against control recording only 10.98 cm. It is concluded that the papaya varieties viz., Coorg Honey Dew, Pant Papaya, Co-2 and Co-7 possess better seed germination, seedling growth and vigour are highly suitable for commercial cultivation in north eastern region of India and their germination and seedling health can be improved by treating with GA 3 100 ppm.

ASSESSMENT OF HYBRID VIGOUR IN TROPICAL PAPAYA (CARICA PAPAYA L.)

The papaya (Carica papaya L.), native to tropical America is a member of the family Caricaceae. One of the normal methods of crop improvement in papaya is through exploitation of hybrid vigour. This investigation was carried out at Department of Fruit Crops, Horticultural College and Research Institute, Tamil Nadu Agricultural University, Coimbatore-3, India during the year 2001 to 2003. A total of five hybrids developed by crossing five dioecious parents and five hybrids developed by crossing 5 gynodioecious parents were evaluated along with their parents for yield and quality parameters. The hybrids CO 2 × Pusa Giant and CO 5 × 9-1(D) registered significantly favorable negative heterosis for days to flowering. The hybrids CO 2 × Pusa Giant, 9-1(D) × CO 5, Pusa Dwarf x 9-1(D) registered high positive significant heterosis for number of fruits. Except the cross CO 3 × CO 7, all other gynodioecious hybrids recorded high positive heterosis over both the mid parents and better parents for number of fruits. The cross, CO 7 x Exotica was highly heterotic for fruit number. The dioecious cross CO 2 × CO 5 showed high positive relative heterosis for fruit weight. Except IIHR 37 × Coorg Honey Dew, all other four gynodioecious hybrids showed high positive significant heterosis and heterobeltiosis for fruit weight. The dioecious hybrid CO 2 × CO 5 registered a high fruit length and a high circumference. Only the cross CO 7 × Exotica registered a high negative heterosis for cavity index. The cross Pusa Dwarf x 97 (D) registered positive heterosis for papain recovery. The crosses Pusa Dwarf × 9-1(D) and HHR 37 × Coorg Honey Dew, the gynodioecious crosses, CO 3 x CO 7 recorded moderate mean and significant heterosis for carotene content. The hybrids 9-1(D) x CO 5 and CO 3 × CO 7 registered not only high heterosis for ascorbic acid but also recorded significant negative heterosis for total acids. Higher flesh thickness with maximum heterosis was observed in the cross CO 3 × CO 7.

PAPAYA DISEASES IN BIHAR: AN OVERVIEW

Papaya occupies an important position among fruits grown in Bihar. Over the past two decades this crop has experienced considerable reduction in yield due to attack of various diseases. According to an estimate, yield reduction up to 50% has been observed within last 18 years. So a systematic survey was conducted during 2000-08 in different districts of Bihar viz., Samastipur, Muzaffarpur, Vaishali, Siwan, Saran, Katihar, Saharsa, and Bhagalpur to quantify losses due to major diseases of papaya in the state. During the survey two viral diseases were recorded i.e. leaf curl and Papaya ring spot virus. Leaf curl incidence varied between 12 to 27%, while PRSV incidence was most rampant showing cent per cent incidence in all the districts under the survey. Disease symptoms were some times visible in the nursery too. No variety showed tolerance/resistance against the disease. Due to severe disease incidence, area under papaya cultivation is shrinking every year. The entire papaya varieties viz. Pusa Dwarf, Pusa Nanha, Pusa Delicious, Red Lady, Coorg Honey Dew and the local ones were found susceptible. In Samastipur district, after first fruiting, all the leaves of the plant dropped due to severe PRSV attack and gradually the papaya plants succumbed to death. In some cases, papaya plants produced new tiny leaves (rosettes at the top) but affected plants produced very poor yield i.e. less than 10 kg/plant. It is very difficult to continue the crop stand even up to 2 nd year fruiting due to heavy pressure of PRSV in the state. Among fungal diseases damping off, collar rot and fruit rot, were frequently observed in all the districts under survey with varying level of incidence. Damping off disease was recorded only in nursery, while collar rot disease was recorded at various stages of plant growth. Fruit rot disease was incited by a number of fungi though Colletotrichum gloeosporioides was predominant. Fruit rot was observed at different stages of fruit growth but immature fruits were highly prone to this disease. This study may serve as a guide for planning effective management of papaya diseases in this part of the country.

EFFECT OF DIFFERENT SPACINGS ON GROWTH, YIELD AND YIELD CHARACTERS OF PAPAYA (CARICA PAPAYA L.) CV. COORG HONEY DEW

The investigation to assess the effect of different spacing on growth and yield of papaya was conducted at Allahabad Agricultural Institute-Deemed University, Allahabad during 2002-2003. The experiment comprised of five spacing as treatments viz. 2×2, 1×1, 1.5×1.5, 2.5×2.5 and 3x3 m us papaya cv. Coorg Honey Dew was taken for study. Vegetative growth characters like plant height, numbers of leaves and internodal length showed significant difference among all the treatments. Maximum plant height (261.7 cm), number of leaves (30), and internodal distance (2.60 cm) were observed with 1×1, 2.5×2.5, and 1×1, respectively. Flowering attributes and fruit set characters showed significant response with 2.5×2.5 m spacing. Maximum average fruit weight (120.305 g), length of fruit (22.45 cm), width of fruit (33.35 cm), and fruit yield (120.11 tonnes/ha) were recorded plants with a spacing of 2.5×2.5 m.

GENETICAL STUDIES IN PAPAYA (CARICA PAPAYA L.)

Genetical studies in papaya were carried out using the variety Coorg Honey Dew. The purification programme in the variety Coorg Honey Dew was taken up and the data were recorded from the S 2 to S 4 generation of sibmated progenies. The variety Coorg Honey Dew yields big sized fruits of about 1.5-2.0 kg, pulp is yellow in colour and fruits are sweet to taste with a TSS of 12°Brix. The sibmated progenies were studied for uniformity in fruit size and shape. A total of ten half-sib families (25 trees/family) were used for the study. Genotypic variation and phenotypic variation was highest in S 2 generation, while in S 4 variation it was observed to be low. The PV and GV were observed to decline with the progress of the generation. The genotypic coefficient of variation was lesser than the phenotypic coefficient of variation implying the role of environment influencing the characters. High heritability was recorded for all the characters except inter nodal length and pulp thickness. Very little difference was noticed in the heritability values between S 3 to S 4 generation. Among the characters, high genetic advance as percent mean was recorded for the characters of fruit weight, fruit length and number of seeds, while other characters exhibit moderate to low. Heritability and genetic advance as percent mean was obtained high for the characters of fruit weight and fruit length. The correlation studies showed that plant height at first fruiting were positively correlated with fruit length and first flowering height. The study indicated that three generation of sibmating considerably reduced the variability in morphological and yield characters.

PERFORMANCE OF COORG HONEY DEW PAPAYA UNDER ORGANIC FARMING REGIMES IN THE HILL ZONE OF KARNATAKA

The urge to obtain increased production and higher returns have lead to indiscriminate use of chemical fertilizers in papaya production that has resulted in depletion of soil fertility. It has therefore become imperative to adopt of organic farming practices for sustainable production of quality fruits. In the present investigation, effect of organic manures on growth, yield and quality of Coorg Honey Dew papaya was evaluated through seven treatments with three replications during 2004-2007. The treatments consisted of T 1 - check (intensive farming with 250:250: 500 g NPK/plantlyear in six split doses), T 2 - organic farming with FYM 20 kg/plant, T 3 - urban compost 13.5 kg/plant, T 4 - sun hemp 25 kg/plant, T s - sun hemp 40 kg /plant + rock phosphate 300 g/plant and T 6 - neem cake 4 kg + wood ash 2.5 kg/plant, T 7 - rural compost 35 kg/plant. The organic treatments were imposed in two splits with interval of once in six months. The treatment, intensive farming with 250:250:500 g NPK/plant/year recorded maximum plant height, stem girth, number of leaves, yield/tree, number of fruits per tree, fruit weight, pulp thickness and number of seeds which were significantly superior to all other treatments. The results indicated that growth and yield characters as influenced by organic manures were on par with the intensive farming of chemical fertilizers. Further, application of FYM 20 kg/plant recorded maximum total soluble solids, ascorbic acid, total sugar and the least value of titrable acidity as compared to intensive farming and other organic treatments. Significant influence of different organic manure treatments on growth and yield characters was observed and it can be inferred that application of organic manures influenced growth, yield and quality characters in Coorg Honey Dew papaya.

Effect of VAM inoculation on plant growth, nutrient level and root phosphatase activity in papaya (Carica papaya cv. Coorg Honey Dew)

Papaya (Carica papaya cv. Coorg Honey Dew) plants inoculated with the VA mycorrhizal fungiGlomus mossae andG. fasciculatum in sterilized nursery soil showed improved plant height, dry matter as well as P, N and Zn concentrations with no or low levels of phosphorus application. There was an enhanced alkaline and acid phosphatase activity on the root surface and also in the enzyme extract of the root of papaya

Biochemistry of papaya (Carica papayaL.) fruit ripening: changes in RNA, DNA, protein and enzymes of mitochondrial, carbohydrate, respiratory and phosphate metabolism

SummaryFruits of papaya cv Coorg Honey Dew were analysed at five ripening stages for RNA, DNA, protein and enzyme activity. Ripening was characterized by an increase in the activities of invertase, cellulase, pectinesterase, catalase, peroxidase, adenosine triphosphatase, acid phosphatase, polyphenol oxidase and mitochondrial glutamate dehydrogenase; and falling levels of amylase, ribonuclease, mitochrondrial adenosine triphosphatase, NADH diphorase and malic dehydrogenase, and of the RNA, DNA, protein and mitochondrial protein contents.

Changes in the Chemical Composition of Four Cultivars of Papaya (Carica PapayaL.) During Growth and Development

SummaryFruits of four papaya cvs, Coorg Honey Dew, Pink Flesh Sweet, Sunrise and Washington, were harvested at various developmental stages and analysed for sugars, organic acids, amino acids, vitamins and minerals. The fruit pulp contained water, 87–94%, carbohydrates, 2–12% at different stages. Sucrose, glucose and fructose formed 7–50%; 14–78% and 13–50% respectively of total sugars. The dry matter content increased from c. 7% 15 days after anthesis to 13% at harvest. During this time there was a steady decline in alcohol-insoluble solids, starch and several minerals and an increase in total sugars. The concentration of total, non-volatile acidity and citric and malic acids decreased to a minimum at the ripe stage. Seventeen amino acids were identified in all stages, the concentration of individual amino acids changing from anthesis to ripening. Ripe samples and 15-day-old samples had almost the same level of vitamin C. The colour break stage was characterized by increases in vitamin A and proteins. Ri...