Passion fruits are loved because of their bitter-sweet taste and high nutritive value. They are also marketable. If you are interested in growing them, you need to watch out for some warning signs:
Vines not setting fruits
The problem is either because of too high or too low temperatures. The optimum temperatures for growing passion fruits range from 20-35 degrees.
Too much rain, boron deficiency, and a long period of foggy weather can also lead to problems. Flower abortion could lead to non-formation of fruits.
Yellow and crinkling leaves
Yellowing and crinkling of leaves is a sign of passion fruit woodiness virus. The virus results in small fruits which are deformed with a thick hard rind and small fruit cavities.
Aphids carry this disease, and most vines will be affected at some point. To avoid it, plant the passion in a warm, sheltered spot to help reduce the incidence of this disease.
Symptoms can appear under stress in cool weather or from a lack of water or nutrients. Affected vines cannot be cured. However, symptoms are temporary, and vines can recover once the stresses are alleviated.
Give your vine warmth, moisture, and nutrients.
Dropping of fruits before maturity
Irregular watering of the plants is one of the causes. Fungal infection, attack by fruit fly or severe mite damage, and severe mite damages are also to blame.
Fluctuation in atmospheric temperatures causes fruit abortion. Other pests such as passion fruit vine hopper can cause fruit abortion.
Regular scouting for pests and diseases can help minimise the instances of fruit abortion. Nutrient deficiencies, especially the trace elements, cause the dropping of fruits to conserve energy for the main plant.
Apply foliar feed to control the problem.
Leaves turn yellow
Leaves turning yellow could indicate that the passion fruit woodiness virus has infected your vines.
Secondly, it could be a result of magnesium and nitrogen deficiency on sandy soil, or extremely cold weather combined with low humidity.
If the new leaves of your vines have yellow veins, most times, a deficiency in sulphur or copper is always evident. If the yellowing affects areas between the veins, it indicates a lack of sufficient iron or molybdenum.
Yellowing of the older leaves, especially between the veins, is a sign of a deficiency in magnesium. Magnesium fertiliser is an appropriate remedy for this problem.
Yellowing of veins in the older leaves is a guaranteed sign of nitrogen deficiency and should be corrected accordingly; if both old and new leaves of your passion fruit vines turn yellow, then it is zinc deficiency.
Bumpy or malformed fruits
This could be due to the passion fruit woodiness virus, especially if the leaves turn yellow and mottled.
It could also happen because of Boron deficiency or insect damage, particularly fruit fly. In the case of the passion fruit woodiness virus, the fruits appear deformed, hard, and bumpy.
Once you notice these symptoms in your orchard, get rid of the affected plants and spray against aphids that transmit the virus.
Shriveling is normal for passion fruits after dropping on the ground when mature. However, if this occurs earlier, it could be caused by fruit fly and sucking bug damage, poor pollination, boron deficiency, and insufficient irrigation when a heavy crop is set.
Ensure that you give your vines appropriate nutrients for optimum and vigorous growth while watching for pests and diseases.
Fruits and leaves with spots
Brown is a serious fungous disease, which affects leaves, stems, and fruit. The notable symptoms on leaves include small brown spots appearing first.
These enlarge to develop a lighter-coloured central area and become irregular or angular. On stems, elongated dark-brown lesions appear, usually near leaf axils or where stems have rubbed against the supporting wire.
The infection spreads from these points, and whenever the stem becomes completely encircled, the shoot suddenly wilts and fruits collapse.
On fruit, spots first appear as pinpricks, which enlarge into sunken circular lesions with brownish centers. Eventually, the rind around the diseased area becomes wrinkled, and the fruits shrivel and drop.