Jatropha pests & diseases
Information below contains picture material and explanation on various pests and diseases.
The attack of pests and diseases is a limiting factor in achieving optimum production, and some time even makes harvests fail. If Jatropha curcas is cultivated as fences or in intercropping systems, the problem of pests and diseases is not very significant, and can in this case be overcome easily. But if the cultivation is done in large scale monocultures, pest and disease control may become important. There are several techniques to be adopted in pest and disease control such as mechanical, cultural, biological and chemical controls.
FACT Foundation has a datasheet on Rainbow shield bug Calidea dregii (see picture below) prepared by Flemming Nielsen. To download the full document, click here.
Other interesting information can be found in:
The information below is from the book "Jatropha curcas as Biofuel Feedstock"from Lembaga Penelitian dan Pengabdian Kepada Masyarakat, Institut Pertanian Bogor, LPPM IPB.
divided in 2 groups, namely the young and the mature plant pests.
1. Young Plant Pests
Pests which attack the young plant consist of cutworm, scarabaeid beetle, grasshopper, army worm larva.
a. Cutworm (Agrotis ipsilon)
This worm attacks seedling and young plant which is just appeared from the soil surface. It is indicated by the stem which cut near the soil surface and the plant will be withered.
Mechanical control can be done by collecting the larva around the plant and kill them. Cleaning the land from the weeds left several weeks before planting will help to reduce the potency of the worm. Toxic bait can also be used such as bran, sawdust, or cassava mixed with insecticides. The mixture is poured out around the plant, after the attack is noticed. Insecticide can be in liquid form sprayed at the lower stem and the surrounding soil.
Granular insecticides can be mixed with soil at the time of plowing and harrowing. Several insecticides used are those which contain active ingredients such as deltamethrin, thiodicarb, carbofuran, or beta cyfluthrin. Below a picture of larva and adult specimens of Agrotis ipsilon:
a. Scarabaeid Beetle
The larva (family Scarabaeidae) can destroy the root of plant. This pest can be found in sandy soil, land with green manure, and land with good drainage. The grubs can easily be found around the plant. In the beginning, the grubs will eat humus or other organic materials, and then they will attack the roots. Larva attack on the young plant may kill the plant.
Plants which grow healthy and strong are more resistant to this pest. Land sanitation may reduce the attack. For a heavy attack, a systemic insecticide can be used. Insecticides with carbosulfan and carbofuran as active ingredients can also be used, if needed.
Some kinds of grasshopper may attack the Jatropha curcas plant. Valanga nigricornis and Locusta migratoria may attack the plants anytime. However, in Indonesia, the attack of L. migratoria is seldom occurred. Generally heavy attack would be occurred on the young plant. The attack is periodic and suddenly. That is why spraying with insecticide is not always successful. The recommended insecticides are betacyfluthrin, cypermethrin, thiodicarb, MIPC, and fipronil but the application should be careful and wise. Below a pciture of a grasshopper on Jatropha:
a. Army worm (Spodoptera litura)
The distribution of this pest is very wide especially in Asia, Pacific and Australia. About 120 kinds of plant are used as host plant by this pest, such as tobacco, corn, paddy, tomato, chili and legumes including soy bean, Jatropha curcas and taro.
The larva eats the leaves of the young and mature plants, often left the leaves bited. If the attack is heavy, only bones of the leaves will left, and plant becomes bald.
In nature, there are several natural enemies of this pest such as egg parasitoid Telenomus spodoptera (Hymenoptera: Scelionidae), larval parasitoid Microplitis manilae (Hymenoptera: Braconidae), predator from Carabidae, pathogen NPV and Borrelinavirus litura.
Sometimes, it is difficult to control this pest because it comes unexpectedly. Mechanical control is done by collecting the egg masses and young larvae and then kill them. If the population is high, insecticide with Bacillus thuringiensis or Spodoptera litura-NPV (S1-NPV) with concentration 6 × 1.011 polyhedral inclusion bodies (PIB/ha) can be applied. Another way is to use botanical insecticide from Azadirachta indica seed with concentration of 4 g/liter of water. Synthetic insecticides used are betacyfluthrin and prothiofos but should be applied well.
2. Pests of Mature Plants
The pests which attack the mature plant consist of stem, leaf, flower and fruit pests.
a. Pest of stem (Ostrinia furnacalis and Xyleborus spp.)
Generally pest which damages the stem is the stem borer. In Indonesia there are two potential stem borer namely O. furnacalis and Xyleborus spp. The stem damage usually is caused by the old larva. The stem attacked usually fall down or the plant broken down by the wind. Sometimes there is a hole at the stem, indicating as entry poit of larvae. Here is a picture of egg mass, larva, and the attack symptom of Spodoptera litura:
Good maintenance of the plant will reduce the population growth of this pest. All trash due to pruning should be abolished or burnt. Insecticide can also used such as carbofuran. Below a picture of O. furnacalis larva and adult:
a. Pest of Leaf
Pests of leaf found in Jatropha curcas are leaf caterpillar, nettle caterpillar, leaf hopper and mite.
1. Leaf Caterpillar (Achaea janata)
This pest is able to eat all the leaves in a short time. Heavy attack will influence the quantity and quality of the seed.The picture below shows A. janata, it can eat all the leaves in a short time.
Pest control through mechanical technique is to collect the old larva and then burnt. Planting distance will prevent the larva move from one plant to another. Another way is to throw away the attacked leaves where many young larvae attached at the lower surface of the leaves.
Until now, there is no variety available which can stand A.janata. Natural enemies are noted such as Trichogramma evanescens (egg parasitoid) and Microplitis maculipennis
(larval parasitoid). Botanical insecticide which contains A.
indica extract can be used as well as the synthetic insecticide such as alfamethrin.The picutre below shows a larva of the nettle caterpillar.
2. Nettle Caterpillar (Parasa lepida)
This pest belong to ordo Lepidoptera, family Limacodidae may attack the Jatropha curcas periodically. The female adult lays its eggs on the soft part of the plant in an egg mass. The picture below shows (a) Nymph and (b) curly leaves, caused by leaf hopper attack:
The size of the caterpillar is 1.5-2.5 cm and the color is green and blue length wise. The pest produces certain chemical compound which stung the skin. This pest moves like snail. Initially they live in group on the leaf, but then spread to all parts of the plant as the larva grows older.
Mechanical control is performed by collecting the young larva and the cocoon, and kills them by soaking in water or kerosene. Bio-control agents such as pathogen (fungi and virus) and parasitoid are able to be used. Pathogen associated with this pest is Cordyceps cocconae, while the parasitoid is Apanteles parasae. Chemically control can be done by spraying organophosphate insecticides or using biological insecticide agents containing Bacillus thuringiensis.
3. Leaf hopper (Empoasca sp.)
Besides Jatropha curcas, this insect which belong to ordo Homoptera also attack tea and others. This insect is the main pest of Jatropha curcas in tropic and sub-tropic regions. On the field, they could be found for the whole year, but very dangerous to the plant on the seed bed.
Female lays its eggs on the leaf net, close to the leaf bones at the lower surface. Nymph and adult suck the plant sap from the lower surface of the leaf and make it dry and die. Sometimes, the curly leaf occurred at the tip.
The color of the leaf has influence to this pest. Jatropha curcas with low content of carotene is more tolerant to this pest. The pest also does not like thick wax found in the flower. Alternative control is by using systemic insecticide. On seed bed, imidachloprid, beta cyfluthrin or carbosulfan may also be applied.
4. Mite (Tetranychus sp.)
Mite may damage the leaf and makes the plant weak. Jatropha with no wax on the flower is more resistant to this pest. Mite is a polyphagous organism that can attack various plants such as cotton, tomato, legumes, citrus, papaya, cassava, peanut and weeds.
The symptom of the attack is the leaf become yellowish and then rust. This leaf is shrinking and reddish in color and then fall to the ground.
Mites are commonly found at the lower surface of the leaf, looks like yellow or red spot. Mites can only make the leaf fall, but does not kill the plant. The top leaves attacked will become malformation.
The spreading of mites may through the falling leaves, blows by the wind or through contact with the worker in the garden or estate.
The natural enemy of this pest is predator from Phytoseiidae family which attacks the eggs and larva. In addition beetle of Coccinelidae, Stethorus sp. also attack the pest.
Sanitation of the plant area is important. Collect all thrash and the falling leaves and burnt.
Acaricide or miticide with propargit, dicofol, tetradifon, amitraz and dinobuton as active ingredients can be used as chemical control agents. Spraying from below, upward and directly pointed to the mites. Frequency of spraying can be many times as required.The picture below shows eggs and an adult specimen ofTetranychus spp.:
5. Ear corn caterpillar (Helicoperva armigera)
This pest is a polyphagous insect. Its other host plants are soybean, tomato, chili and cotton.
Application of chlorphyriphos, lamda sihalothrin, fenvalerat, permethrin or sipermethrin may reduce the population of the pest in the field. The other alternatives are H. armigera–NPV Virus, Trichogrammat armigera egg parasitoid, and bio-insecticide from Azadirachta indica powder with concentration 4 g/l of water.
The picture shows a larva of Helicoverpa armigera:
b. Pest of Flower and Fruit
The most important insect to be considered is the one which attack the tip of the plant, flower and capsule of fruit which is still growing.
The symptom of the attack is many beginning from the young leaf stalk, sporadic falling of fruit, up to the death of all panicles.
1. Stink bug (Nezara viridula)
Stink bug belong to Pentatomidae is very important in the tropical region. This pest some times attacks the Jatropha curcas at the flowering time, which causes heavy damage to the fruit capsule. This pest is spreading all over the world and easy to be recognized for its green color. The other host plants are paddy, tomato, legumes, chili, cotton, potato, soybean and corn.The picture here shows an adult of Nezara viridula:
The main damage is not due to the direct suction of plant sap but by the toxin in its saliva. This toxin may wither the plant, and causing the death of leaves and tip of the plant.
To control the pest is to collect the eggs and the insects and burn them or can be done by avoiding the host plant around the Jatropha curcas. If population is too high, application of insecticides is recommended such as chlorfluazuron, diflubenzuron, alfamethrin, and lamda cyhalothrin. Below a picture of Chrysocoris javanus attacking the fruit by sucking the fruit fluid:
2. Chrysocoris javanus
The color of this pest is very loud namely red with black line across its body. Its length can reach 2 cm. This pest is found in Ricinus communis and Jatropha curcas. It attacks the fruits by sucking the fruits fluid. This pest is easy to be recognized thus the control recommended is mechanically, especially when performing pruning and maintenance of the plants.
3. Tip borer caterpillar (Dichocrosis punctiferalis)
The pest bores the tip of the plant and the fruit. Its spreading covers, Southeast Asia, Australia and Pacific Islands. In Java, it is found in Low land area up to 1750 m above the sea level.
Its attack usually occurred when flowering season begins. Female imago lays its eggs on the soft part of the plant. After the eggs hatched into larva, the attack begins at the tip of the young plant, or at the seed of an old plant.
Mechanical control is to collect the tips and the seeds attacked and burn them up. Chemically control is by spraying with monocrotophos and bensultap at the flowering season, or carbofuran prior to flowering season and 15-20 days after that.
Several important diseases which attack Jatropha curcas, among others are spots on seedling, alternaria spots, rust, cercospora, leafspots, fusarium wilt, botrytis spoiled and bacteria leaf spots.
1. Spots on seedling
This disease mostly occurs in the rainy season. Generally they attack seedling or young plant and the damages may reach 30-40%. The appearance of the disease is a circle spots on both leaf surfaces which finally wider and the leaf spoiled. Sometimes it spreads further to the stem which may kill the plant. The old plant can also be infected, but the intensity of damage is lower than that found on seedling. The leaf color usually changes and becomes yellow and finally brown. Good selection of seed and good irrigation system will reduce the plant damages.
2. Alternaria Spots (Alternaria ricini)
If the humidity is high, this disease develops very quickly on the fruit capsule and the fruit become black. If the attack occurs in the beginning flower forming, the buds may die. And if it occurs at the end of flowering, the flower is opened but no fruit capsule is formed. If the attack is light, the flower may dry.
The pathogen may attack the whole plant. Initially the attack appears on the leaves. If the infection is intensive, the plant become stunted, and may also die. The disease spot may appear all year round but intensive attack occurs in the rainy season. The disease is caused by Alternaria ricini.
The disease may spread through seeds, internally or externally. It may also make the sprouts fall and spots on the seedling in the seed bed. The disease will looks heavy if it has something to do with bad variety, high humidity and temperature of 16-20oC. Seed treatment will be useful to prevent first phase of its development.
The disease looks like rust spots on the lower surface of the leaf and yellow in color. A heavy damage may dry the leaf. The disease is caused by Melapsora ricini. The pathogen attacks many plants from Euphorbiaceae.
Spraying or dusting using sulfur powder and mancozeb fungicide may reduce the intensity of the attack.
4. Cercospora leaf spots
The damage caused by this disease on Jatropha curcas can be very heavy. The symptom is that black spot or brown spot surrounded by ring with pale green in color. The spots are found on both leaf surfaces. When the spot is getting bigger, the spot is become gray, surrounded by brown color. Initially the spot is round and finally the spot form is irregular.
To control the disease it is recommended to use variety resistant to this pathogen. If there is an attack, fungicides with carbendazim or mancozeb as active agent can be used.
5. Fusarium wilt
The cause of the disease is Fusarium oxysporum and may attack the plant in the seed bed or in the field. If the seedling is attacked, the leaves become pale green, and withered and finally died. Leaves on the lower part of plant will fall and only leaves on the upper part will left.
Several strategies can be done to control the disease, such as seedling selection, resistant varieties, no flooding around the plant, burn the trash or the attacked plant. The chemical control is by soaking the seed in carbendazim or use biological control by using Trichoderma viridae.
6. Botrytis Spoiled
Initially the symptom is blackish spot on the flower. It is caused by Botrytis ricini which become a serious problem in the rainy season when the fruit capsule is formed. The disease is well developed in a cool temperature and rain. The infected flower will be spoiled and covered by gray mold. The pathogen will spread to all the flowers and the fruit capsule.
Actions to reduce the infection are to prevent over irrigated, not densely populated, to burn the infected plant. Chemical control is by the application of carbendazim or thiophanate within 15 days interval.
7. Bacteria Spots
This disease is caused by Xanthomonas ricinocota bacteria which may attack the cotyledon and the leaf. The symptom is the black spots, round and irregular in form. This bacterium grows well at a temperature of 31oC.
To reduce the attack, field sanitation should be carried out. Heat treatment for the seeds for 10 minutes is recommended. Chemical control is by using bactericide.