Everything you need to know about guava cultivation and harvest! Learn about: 1. Botany of Guava 2. Origin of Guava 3. Climate and Soil 4. Orchard Cultural Practices 5. Propagation 6. Planting Operation 7. Crop Regulation 8. Flowering and Fruiting 9. Training and Pruning 10. Harvesting and Handling 11. Varieties.
Botany of Guava:
Most of the cultivars of guava belong to Psidium guajava L. Apart from cultivated guava, some other allied species with edible fruits are there. The genus Psidium belongs to family Myrtaceae and contains about 150 species.
The important species are described below:
i. Psidium Guajava L. (Common Guava):
It is a small tree, sometimes growing to 8 or 9 metres. The trunk is slender with greenish brown scaly bark. The young branchlets are quadrangular. The leaves are oblong-elliptic, oval in outline, 7-15 cm long, acute to round at the apex, finely pubescent below, with the venation conspicuously impressed on the upper surface. White solitary flowers or several together upon a slender peduncle are produced on branchlets of recent growth and are 2.5 cm broad. The calyx splits into irregular segments. In the centre of the flower is cluster of long stamens.
Ovary is inferior. The fruit a berry is round, ovoid or pyriform, 2.5 to 10 cm in length, commonly yellow in colour with flesh varying from white to deep pink or lemon. Edible portion of fruit is thalamus and pericarp. Numerous small reniform, hard seeds are embedded in the soft flesh towards the centre of the fruit. The flavour is sweet, musky and the ripe fruit is aromatic in a high degree.
ii. Psidium Cattleianum Sabine (Cattley or Chinese or Strawberry Guava):
It is a native of Brazil. Cattley guava is ornamental in appearance and is a favourite garden shrub in many regions. It is bushy shrub, sometimes becomes a small tree up to 7 metres high. The bark is smooth, grey brown in colour and the young branchlets are cylindrical. The leaves are elliptic to obovate in outline, acute, 5-7 cm long, thick and leathery in texture and deep green in colour.
The flowers singly produced upon axillary peduncles are white and nearly about 2.5 cm broad. The calyx is obscurely lobed. The fruit is obovate to round in form 2-3 cm in diameter, purplish red in colour with a thin skin. The flesh is soft, white towards the centre and contains numerous hard seed. The flavour is sweet and aromatic suggesting that of strawberry.
iii. Psidium Guineense Sw. (Brazilian Guava):
It is a shrub or small tree of slender habit. The young branchlets are compressed-cylindrical and finely hairy. The leaves are ablong-oval, acute or obtuse, 8-12 cm long with lower surface pubescent. The flowers of which, one to three are borne upon a single peduncle. The fruit is round or nearly so, 2-3 cm in diameter, greenish yellow and rather hard when ripe. The flesh is whitish containing numerous small seeds. The flavour is sub acid and not as musky as that of common guava.
iv. Psidium Friedrichsthalianum Berg. (Coosta Rican Guava):
It is a tall tree about 7-10 m high having slender and smooth branches, oval or oblong-oval, smooth leaves which are almost glossy above and puberulent below. The fruits of this species are small and globose in shape. The fruits have high acid content. It is a wilt resistant species and used as a wilt resistant rootstock in different parts of the world.
Origin of Guava:
Guava (Psidium guajava) is the fourth most important fruit of India in area and production. It occupies an area of 154.6 thousand ha. Even though guava occupies a large area, grapes and apple are gaining greater importance on account of their greater money-making potential. Guava has become so naturalised in the country that it is hard to believe that it is not native to India but was introduced from tropical America. It, however, came to India at a very early time before the 17th century.
It is very rich and cheap source of vitamin C and contains a fair amount of calcium. It makes an excellent jelly and does not lose the vitamin C in the preserved forms. The vitamin C content of fresh ripe fruit varies from 150 to 350 mg per 100 gm of pulp. The corresponding figure for oranges is 30 to 70 mg. Its cultivation is gaining importance in Hawaii and Florida in the U.S.A. where more sour types make excellent jellies and a drink called guava nectar.
Botanically, guava belongs to the large family, Myrtaceae. This family includes the eucalyptus tree, several tropical species like cloves, nutmeg, all spices, cinnamon and also the Jamun, Jambolan or Java plum (Syzygium cuminii). The Jamun is rarely grown under cultivation except as a border tree. A wild Jaman (S.fruticosum) called jamoa is grown as an avenue tree or as a windbreak in U.P. A similar fruit, the gulab-jaman or rose apple (S. jambos), grows up to elevation of 1300 metres in South India and rarely at the foot of the Himalayas.
Guava is fifth important fruit covering an area of 1.54 lakh ha with a total production of 17.15 lakh tonnes. Major guava producing states are Bihar, Maharashtra, Karnataka and U.P.
Apart from cultivated guava, some other allied species with edible fruits are also found in India. But they are not commercially important. The strawberry guava or cattley guava (P. cattleianum) has purplish red fruits about 2.5 cm in diameter. The tree is smaller than that of ordinary guava, is more cold-hardy and has shiny leaves.
It has a yellow fruited form (var. lucidum), which grows in South India from the plains upto an elevation of 1700 metre. The Guinea guava or Brazilian guava (P. guinense) has small fruit of poor quality and rounded branches. The young branchlets in the ordinary guava are four-sided. The feijoa or pineapple guava (Feijoa sellowiana) is grown on the hills of South India. It is also reported to be growing in Bengal.
Guava grows in a wide area in India, but guava grown in Allahabad are famous all over for the fine quality of the fruit. It is a sub-tropical and tropical fruit, which requires a distinct winter for developing good fruit quality which is influenced greatly by the climate. It can withstand drought, but only a few degrees of frost. It does not thrive if the annual rainfall is more than 250 cm.
The importance of guava is due to the fact that it is a hardy fruit which can be grown in poor alkaline or poorly-drained soils without any manuring or irrigation. It can grow in soils with the pH ranging from 4.5 to 7.5.
Climate and Soil Required for Guava Cultivation:
Guava cultivation can be extended to varying agro-climatic regions owing to wider adaptability. It is successfully grown under tropical and subtropical climate. Guava does well up to an altitude of 1000 to 1500 metres. It grows best with annual rainfall below 100 cm restricted between June to September. The optimum temperature requirement of guava ranges between 23°C – 28°C. The areas having distinct winter season, is considered best for increasing yield and improving quality.
The humid condition leads to luxurient growth of the trees and yielded poor quality fruits. The young plants are susceptible to drought and cool temperature. It can be grown as rainfed as well as irrigated crop depending upon agro-climatic conditions. At the time of flowering and fruiting, it requires dry climatic conditions. High temperature and high velocity winds at fruit development period lead to heavy fruit drop.
Guava is a hardy fruit tree and can be grown to wider adaptability even under marginal soil. It can thrive well on all types of soil. Guava can be grown on poor wasteland soils. It is sensitive to waterlogged conditions. For successful cultivation, the soils for guava are deep, friable, light sandy loam to clay and well-drained soils. Guava is known for its tolerance to salt. It can grow in soil having pH 6.5 to 8.5. Guava is a surface rooted plant; therefore, the surface soil should be rich. Maximum concentrations of roots are between 0-20 cm soils depth.
Orchard Cultural Practices for Cultivating Guava:
i. Irrigation:
The young guava plants need irrigation at weekly interval during summer month and 2-3 irrigations during winter months. To bearing trees, irrigation should be given for flowering and better fruit-setting at an interval of 2-3 weeks during summer months and at monthly interval during winter months. Irrigation is also essential to check excessive fruit drop during summer months. Irrigation during winter was also found effective in reducing fruit drop and improving fruit size of winter crop. The cropping pattern in guava (for heavy winter crop) can be regulated to some extent by withholding irrigation during hot summer month (May).
ii. Intercropping:
The interspace can be economically utilised by suitable intercrops during the pre-bearing period of guava orchards. During initial 3-4 years, the vegetables like brinjal, radish, carrot and okra can be inter-planted in the vacant land. The leguminous crops like cowpea, guara, gram, beans etc. should be sown as safe intercrops. Intercropping should be stopped when the trees attain age of being fully grown.
iii. Weed Control:
Pre-emergence application of Hexuron 80 WP (diuron) @ 4 kg per hectare can be made during first fortnight of March for rainy season crop and during first fortnight of September for winter season crop when field is free from weeds and stubbles. Glycel 41 SL (glyphosate) @ 4 litres per hectare as post-emergence should be sprayed when the weeds are growing actively; preferably before weeds flower or attain a height of 15-20 cm i.e., during second fortnight of March for rainy season crop and during second fortnight of September for winter season crop. Dissolve the herbicides in 500 litres of water which is enough to give complete coverage on weeds in one hectare. Spray Glycel during the calm day to avoid spray drift to the foliage of the trees.
iv. Manuring and Fertilization:
The requirement for manure and fertilizers to guava crop varies with varieties, age of the plants, fertility status of soil, climatic conditions and management practices. The fruit of guava are borne on current season’s growth; therefore, manures and fertilizers encourage vegetative growth and fruiting. Fertilization of guava not only increased the yield but also improved the fruit quality.
To five year old Sardar cultivar application of 25 kg FYM, 600 g N, 300 g P2O5 and 300 g K2O was recommended for obtaining higher yield. In West Bengal, 260 g N, 320 g P2O5 and 260 g K2O per plant in two equally split doses once in the month of January and another in the month of August was suggested.
Farmyard manure should be applied in May. Half of the inorganic fertilizer should be applied in May-June and the remaining half in September-October.
Propagation of Guava:
It is still common to raise commercial orchards by propagation from seeds. This practice is not advisable because this would lead to lot of variation among the trees not only in the size productivity of the trees but also in fruit size and fruit quality. Hence, it is very important to plant an orchard only with vegetatively propagated plants of known variety.
The propagation is commonly done through patch-budding, air-layering and inarching. However, improved patch budding is efficient than simple patch budding and enhances the chances of budding success. Seeds of Sardar guava are commonly used for raising rootstock which are easily available and possess the qualities of a good rootstock. Portugal rootstock of guava is most suitable for Sardar and Allahabad Safeda varieties, as it improves fruit yield and weight. It also imparts vigour and wilt tolerance to these scion varieties.
Propagation Techniques:
Patch or improved patch budding may be done during May-June when it yields 75-80 percent success. Freshly cut angular bud-wood from current season’s growth should be employed for budding. A semi-circular or a rectangular patch of bark (2.5 x 1.0 cm) with two buds is removed from the scion stick taking care that the bark does not split. It is then fixed on the exposed portion of the rootstock and tied immediately with the polythene strip leaving both the buds uncovered.
The polythene is removed after a week or so when the bud-take has occurred. When the shoots developing from the buds have attained a length of 15 – 20 cm, retain the vigorously grown shoot and remove the weaker ones. Inarching is another common method of vegetative propagation and about 80-90 percent success can be achieved when it is practiced during July-August.
Wedge grafting can be performed on rootstock seedlings of 2.5 – 3.0 cm thickness during February. The scion sticks should be defoliated 8-10 days prior to grafting. Air-layering is also practiced for multiplication of guava plants and the best time for doing this method is February-March and July-August. For better results, the use of indolebutyric acid, indoleacetic acid and naphthalene acetic acid can be made.
Planting Operation of Guava:
The field should be deeply ploughed and properly levelled before planting. Guava may be planted in February-March or August-September with earth balls or bare rooted. In later case, the plants should be defoliated and the roots covered with some moist material. Guava is best planted at the distance of 6.5 x 6.5 m apart in square system, thus accommodates 225 plants per hectare.
Plantation can be made with hexagonal system which will accommodate 257 plants per hectare. Guava plants of Sardar cultivar can be planted at a close spacing of 6 x 5 m instead of 6.5 x 6.5 m. With this planting plan 330 plants can be accommodated in one hectare. It has been observed that high density planting had an adverse effect on fruit quality. The total soluble solids, sugars and vitamin C were significantly reduced while acidity decreased with higher plant density. The size of the fruits also reduced considerably due to more number of plants per unit area. The low plant population showed greater spread of the crown.
High density planting causes erect growth of branches making the plant tall and compact. At different places guava is commonly planted at a distance of 3.6 m to 5.4 m (12′ to 18′). High density planting results higher productivity per unit area but there would be reduction in size of fruits. A planting distance of 15′ x 15′ (4.5 m x 4.5 m) with a population of 485 plants per hectare is being followed in certain guava growing areas.
Planting distance of 6 m x 4 m and 6m x 5 m in Sardar and Allahabad Safeda cultvars with the use of 500 and 1000 ppm paclobutrazol and 10 cm pruning in April resulted higher yield and better quality fruits at PAU, Ludhiana. Planting distance of 6m X 2m and 6m X 3m in both these cultivars was not economical. However, at CISH, Lucknow, planting density of 3m X 6m (555 plants/ha) has been found effective in Allahabad Safeda to obtain high yield.
Double – hedge row system of planting with 800 – 900 plants per hectare is beneficial for higher yield in Allahabad Safeda.
Crop Regulation of Guava:
Guava bears two crops in a year. The winter season crop is considered superior in quality than rainy season crop, which gets infected with fruit flies.
In order to get only winter season crop, the following practices may be adopted:
(a) Spray urea 10 per cent or Naphthalene acetic acid (NAA) @ 600 ppm during May when maximum flowers have opened. Each tree needs about 10-12 liters of solution.
(b) Pruning of terminal portions of the shoots upto 20 or 30 cm between 20 to 30 April avoids completely the rainy reason crop.
(c) Irrigation should be stopped during the summer months of April-May.
(d) Apply inorganic fertilizers during the month of June to encourage growth in July-August for getting maximum flowering during August-September for winter season crop.
Flowering and Fruiting of Guava:
Guava tree normally produces as many as three crops in a year, a unique phenomenon of the tropical and sub-tropical regions because there is more than one growing season during the year. In a mild climate, guava can flower and bear fruit throughout the year, provided water and temperature do not become limited factors. But in regions where seasons are quite distinct due to variation in temperature or precipitation or both, specific periods to flowering and fruiting are observed.
In northern India three distinct flowering seasons, i.e., summers, rainy and autumn with the corresponding harvesting periods have been observed. It is a common experience that the quality of rainy season crop is poor. In Punjab and most other parts of northern India, guava flowers first in April-May for rainy season crop and then in August- September for winter season crop.
In addition to the two flowering seasons the trees in western and southern India sometimes flower in October too. In West Bengal, guava flower once in April-May and again in September-October.
The guava bears flowers solitary or in cymes of two or three flowers, on the current season’s growth in the axils of the leaves. The bearing twigs grow a few centimetres long, putting forth 4-5 pairs of leaves. The blooming period varies from 25 to 45 days depending upon the cultivar, season and region of growing. The initial fruit set in guava is quite high and approximately 80 per cent of the flowers set fruits. Due to severe fruit drop only 34 to 56 per cent of fruits reach maturity. The formation of fruit is first noticed after 12 days from flowering. The rainy season crop is harvested during August and winter season during December-February.
Fruits of Allahabad Safeda and Sardar guava take 130 days and 120 days in rainy season crop and 140 days and 130 days in winter season crop to attain the stage of harvest maturity, respectively.
The growth of guava fruits in terms of change in length and diameter can be divided into three distinct phases. It was active upto 50 days of fruit-set in Allahabad Safeda and 40 days of fruit-set in Sardar guava during rainy and winter season crops (Phase-I). In between 50 to 80 days and 40 to 80 days after fruit-set, the growth was very slow in Allahabad Safeda and Sardar guava, respectively during both the seasons (Phase II).
The growth was again very active between 80 to 130 days and 80 to 140 days in Allahabad Safeda; 80 to 120 days and 80 to 130 days in Sardar guava during rainy and winter season crops, respectively (Phase III). In Phase II, seeds start their development faster than the phase I, which results in less development of flesh during this phase.
Training and Pruning of Guava:
Training of guava trees improves fruit yield and quality. Modified leader system of training is generally followed. The main objective of training guava plants is to provide a strong framework and scaffold of branches suitable for bearing a heavy remunerative crop without damaging the branches. The flowers and fruits in guava are borne on current season’s growth, hence, a light annual pruning upto 10 cm tip removal may prove useful to encourage new shoots after the harvest (early April).
Dead, diseased, intercrossing branches and suckers coming up from the base and sides of the framework should be pruned back annually. Pruned plants, however, certainly reduce yield to certain extent.
Harvesting and Handling of Guava:
Guava is climacteric in nature and should be picked when it is mature but firm. Picked at the right stage of maturity, fruits on ripening give excellent taste and flavour, characteristic of a particular cultivar. For successful orcharding, harvesting the fruits at its proper stage of fruit maturity is of utmost importance. The seedling guava comes into bearing very late i.e. after 5-6 years of planting.
However, the grafted or air-layered plants are precocious in bearing and first crop appears at the age of 2 to 3 years. The fruits change their colour from dark green to greenish yellow at maturity. The fruits should not be allowed to over ripe on the trees as they deteriorate in quality and are more liable to be damaged by birds. Individual fruits are picked when they are still hard and firm at regular intervals. Guava fruit must be harvested with great care because of their soft, thin skin. Harvesting is normally carried out by hand to avoid physical injuries. Subsequent handling and transportation of the fruit also need extra precautions to reduce bruising.
The yield of guava varies due to different varieties, age of the plant, fruiting season and orchard management practices. The average yield of seedling trees is obtained approximately one quintal, whereas of grafting trees, the yield can be obtained upto two quintals per tree. It is observed that different varieties produce greater yield in the rainy season compared to winter season. Guava is highly perishable fruit and should be marketed immediately after harvest.
The fruits belonging to, A and B grades which accounted for 72 per cent has better quality and are acceptable from marketing point of view. Highest distribution of fruits was recorded in grade B i.e. 60 per cent. The fruits should preferably be packed in Corrugated Fibre Board Cartons of sizes ranging from 4-10 kg or in bamboo baskets of different sizes.
The fruits of winter guava cv. Sardar harvested at physiological mature stage can be ripened at 20°C in 72 hours and these fruits can be kept for 48-72 hours at ambient temperature in winter.
Proper handling prior to storage is important to preserve fruit quality and to avoid losses due to physical injuries and diseases. Positioning of guava fruits in the natural posture with the pedicel end vertically upward may result in a better keeping quality as compared with fruits kept in reverse or horizontal position. Newspaper should be used as the cushioning material for the fruit.
The fruits of Sardar cv. individually wrapped in newspaper impregnated with biphenyl or KMNO4 and kept at room temperature showed less decay and retained a higher level of ascorbic acid than the control. The guava fruits can be stored upto 6 days in perforated polythene bags and wooden boxes. The guava fruits when picked at proper maturity can be kept at room temperature for one week in perforated polythene bags and for three weeks in CFB cartons in commercial cold store at 0-3.3°C temp, and 85-90% relative humidity.
Allahabad Safeda variety can be stored for 4 weeks in the cold storage (8.5 -14 °C). Lucknow- 49 could be stored well up to one month at 10°C. Dipping of fruits, in 6 or 9% wax-emulsion extended shelf life for one month without any spoilage.
Varieties of Guava:
There is a great variety in the types of fruit. Apple guavas have brilliant red blush. Some types are pear shaped and some even look like a bitter gourd or Karela. Many varieties have red or pink flesh with distinct flavour, but these usually have an inferior fruit quality. A few varieties are seedless, but their yield is poor and they are not economically important. The most famous variety is the Allahabad Safeda with a round smooth fruit and white flesh of excellent quality. The Chittidar is similar to the Safeda except that it has many pinkish red dots of the size of a pinhead on the surface of the fruit.
Lucknow 49 (Sardar) is a seedling selection of Safeda, with a large tree and larger fruit with rough surface. It bears well and is popular in the Pune area and the Araku Valley in Andhra Pradesh with an elevation of 1000 metres, and in other places in South India. Where the winter is warm it does not do well. The Hafshi is a red-fleshed type. In Bihar, apart from Safeda, the other varieties grown are Harijha, Hafshi with dark green fruit. Some of other varieties are Dholka, Nasik and Dharwar.
Recently a number of improved selections from ‘Allahabad Safeda’ have been made. The important ones are ‘Arka Mridula’ from I.I.H.R, Bangalore which is dwarf, has few soft seeds, high T.S.S. and good shelf life.
Seedling selection of coloured guava namely “Lalit” from C.I.S.H., Lucknow has been released for commercial cultivation. The fruits are attractive saffron yellow with red blush, medium size with average weight of 185 g. Flesh is firm and pink with good blend of sugar and acid. It gives 24 per cent higher yield in comparison with popular variety Allahabad Safeda which is suitable for both table and processing purposes.
Pant Prabhat selected at G.B.P.U.A.S.T., Pantnagar (Uttaranchal) has upright plant growth with broad leaves, high production (100 to 125 kg/tree), fruit round shaped, medium size, peal smooth and light yellow colour, white fruit pulp, seeds small and soft as compared to Sardar.
Dhareedar is a seedling selection from Fruit Research Station, Kuthulia, Rewa. Tree is vigorous with erect and upright branching and flat crown, fruit medium to large, roundish ovate, 5-7 raised lines on the surface of mature fruit, peal greenish yellow, sweet fruit.
The hybrids developed are Arka Amulya (Seedless x Allahabad Safeda) from I.I.H.R., Bangalore. Tree is semi- vigorous and heavy yielder with few soft seeds; medium fruit size, white and sweet pulp and good keeping quality.
Safed jam (Allahabad Safeda x Kohir) is evolved at Fruit Research Station, Sangareddy. Medium tree height and good yielder (80-90 kg), fruit round with thin peel and good taste. Seed is soft and located at the core.
Kohir Safeda (Kohir x Allahabad Safeda) has been evolved at F.R.S., Sangareddy. Tree is large, bears profusely (90 to 100 kg/tree) fruit is large with hard seed.
Guava is commonly propagated from seed, which germinates in about three weeks. Boiling the seeds for five minutes, soaking them in water for two weeks prior to sowing or treating them with strong sulphuric acid for five minutes facilitates their germination. Seed viability declines very quickly after extraction from fruits which may be extended by treatment with potassium nitrate or ferulic acid.
In any case the raising of guava plants from seed is not desirable, since the seeding trees differ greatly from the mother-plants. Inarching, which is the common method of propagation in mango, is a successful method of propagating guava. Veneer-grafting, T-budding, Forkert-budding, layering and air-layering or gootee are also practised.
Guava is commonly planted 6m x 6m or 5m x 5m apart accommodating 278 to 400 plants per hectare by the square system of planting. In guava, fruits are borne on current season’s growth and flower appears in the axil of new leaves. Thus it is amendable to pruning. Guava is very suitable for high density planting. It can be planted in a hedge row system at spacing of 6m x 2m.
The trees are trained to form a hedge with inter row spacing of two metres and two metre height. The hedge row system gives almost double the crop per unit area as compared to the usual 6m x 6m spacing. The planting of trees in hedge row system needs regular pruning to keep the plants in the desired size.
Dwarfing rootstock, Aneuploid-82 named PUSA SRIJAN developed at IARI, New Delhi, has also been used for high density planting of Allahabad Safeda with a planting distance of 3 m x 3 m apart. A full bearing high density guava orchard on this rootstock can give 18-20 tonnes fruits/ha. P. pumilum rootstock is also dwarfing. Allahabad Safeda on P. Cattleianum shows high yield. Chinese guava (P. friedrichsthalianum) and hybrid (P. molle x P. guajava) seedling developed at CISH, Lucknow have been found to be resistant to guava wilt disease.
Pruning (3/4 portion) of current season growth from G.B.P.U.A.T. Pantnagar (Uttaranchal) and heading back of branches (pruning) to their half-length (50%) of entire tree from CISH, Lucknow in the month of May is recommended for crop regulation to avoid rainy season crop with increased yield of quality fruits in winter season.
Guava is rarely pruned in North India, but light annual pruning after harvesting to promote vegetative growth and flowering is desirable. In Tamil Nadu, the bearing shoots generally die after the fruit is harvested. Under these conditions, removal of dead shoots and pruning-back of the other shoots are recommended. Pruned trees give larger fruits and early ripening.
Guava bears fruit more than once a year. The flowering in spring gives a crop in the rainy season and the flowering in the early monsoon season gives a crop in winter. In South India, flowering also takes place in October and gives a third crop under irrigation. Guava will bear almost throughout the year here. It is desirable to take only one crop in a year. In South India, the rainy season crop is preferred even though it is of poor quality since the price is high at this time.
The fruits set in spring shed soon in the heat of summer due to water stress. Under these circumstances, the only time the plants would be irrigated is in autumn after the monsoons when the trees are bearing crop. In actual practice, however, irrigation is rarely done. In Western India, root-pruning of guava to regulate the season of harvesting, as is done in the case of mandarins, is recommended in heavy soils only. In lighter soils, withholding of water serves the purpose. In Pune, bending of branches and tying together branches of adjoining trees is recommended to improve fruiting.
Foliar spray of different thinning chemicals like NAA (50 to 100 mg/l), 2, 4-D (50 to 100 mg/l), DNOC (5-10 mg/l) or urea (10 to 20%) during April is effective to thin the summer season flowers and increased yield of the winter crop with high total sugar and ascorbic acid content. Two sprays of 10 per cent fertilizer grade urea on guava cultivar Allahabad Safeda and 20% on cultivar Sardar at bloom (April- May) could eliminate poor quality rainy season crop and increase winter season crop yield by 3 and 4 times respectively as observed at CISH, Lucknow.
Guava does not receive any manure in practice, but it does require some manuring. A bearing guava tree should be fertilized with 300-400 g N, 250 to 350 g each of P and K along with 30 to 40 kg FYM each year. Fertilizers should be applied in two split doses preferably in June and September and placed between tree trunk and the drip line. Application of neem coated urea is beneficial.
Foliar Spray 1.0 to 2% of Potassium (potassium sulphate), and Calcium (calcium nitrate) have been found to be beneficial.
Guava sometimes suffers from the deficiency of zinc. The area between the veins of the leaves develops yellow patches,- the leaves become small and the growth and bearing of the trees are reduced. It is serious in water-logged areas. Spraying the trees with (0.45 kg) zinc sulphate and (0.32 kg) hydrated lime dissolved in 33 litres of water cures this condition.
Internal necrosis followed with hardening of fruits, reduced fruit size and leaf drop are typical symptoms of boron deficiency. Cracking of fruits occur in extreme cases. Spray of boric acid (0.3 to 0.4%) or 0.5% Borax before flowering (July-August) is beneficial.
Guava fruits ripen five months after flowering and they are harvested when their colour changes to yellowish green. Bearing commences when the trees are three years old.
Fruits of guava cultivars Allahabad Safeda and Sardar with specific gravity of 1 to 1.02 have better shelf life and those with <1.00 have good quality. The shelf life can be increased by 2-3 days if fruits are harvested with 8-10 mm stalk. Ventilation of 0.25% LDPE bags increase storage life of winter season Allahabad Safeda upto 12 days with ambient condition and 28 days at 5°C. Guava can be stored for two to three weeks at a temperature of 7-10°C and R.H. of 85 to 90 per cent.
Guava fruits are highly perishable and the birds play havoc with them even when they are not ripe. So it does not pay to plant only a few guava trees, since the cost of birdscaring over a long period is prohibitive.
Guava suffers from many serious pests and diseases. Fruit fly (Bactrocera dorsalis) damage the fruit in the rainy season. The insects lay their eggs under the skin of the fruit. The maggots soften the affected portion of the fruit which rot and make the fruit unfit for sale. Hanging of methyl euzenol bottle traps (containing 100 ml. solution of 0.1% methyl euzenol and 0.1% malathion) at 10 to 15 different places in a hectare, well before ripening of fruits, is highly effective.