Nematode Pests of Horticultural Crops and their Management (1+1)

Papaya, Strawberry and Kiwi

III. PAPAYA

• Papaya, a native of Tropical America is grown all over India leaving apart colder regions of North India.
• Out of several nematodes reported to be associated with papaya only root- knot nematode (Meloidogyne incognita and M. javanica) and reniform nematode (Rotylenchulus reniformis) have been reported to cause economic damage.
• General symptoms of nematode infestation appear in form of patches of poorly growing stunted plants with yellow foliage and poor vigour.
• Application of neem cake @ 2.5 tonnes / ha or carbofuran @ 6 kg a.i./ha successfully controlled the nematode population and increased the yield significantly.

IV. STRAWBERRY
Important nematodes of strawberry include Aphelenchoides spp. (A. fragariae, A. ritzemabosi), which are causal organisms for disease ‘Dwarf Crimp’, ‘Spring dwarf of strawberry’ and ‘Red plant of strawberry’.
Aphelenchoides besseyi causes ‘Summer crimp of Strawberry’.

• In strawberry the nematodes generally congregate about the plant crown where they primarily live as migratory ecto- parasites on buds and leaflets of the growing points or in leaf axils.
• Infested leaves are more brittle.
• Stunting and deforming of buds, leaves and flower occurs and if the main bud is killed, plant may fail to produce more leaves and often dies.
• Symptoms are more pronounced in spring when the young leaves are ‘crimped’.
• In severe cases, the central crown may be aborted resulting in the formation of secondary crowns and delayed flowering.
• Affect on flowering and fruiting results in to poor yields.
• The nematode requires cool, moist conditions to enable it to move on plant surfaces, where it feeds and reproduces.
• Pre-planting sucker dips in hot water at 43.3^o C for 20 minutes or 46.5^o C for 10 min followed by plunging in cold water results into healthy, vigorous strawberry plants, free of nematode infestation.
• A five minute dip in 0.2% thionazin effectively eliminates the nematodes.

V. KIWI

• The fruit is native to China and primarily known as Chinese gooseberry until 1962, when New Zealand growers began to market the fruit as kiwifruit.
• The only widespread nematode damage reported on kiwi fruit is caused by Meloidogyne hapla which induces small, discrete root galls associated with unthrifty plants.
• Reduced nematode population and improved plant status can be achieved with various organic amendments, mulches and biological control agents.