The Gazetteers Department

Besides damage caused by pests, crops suffer from various diseases. The important diseases of various crops in the district together with measures to combat them are given below:―

Of Cereals.

The crops of paddy, rala and nagli are subject to many diseases,; the important ones being Karpa (Piricularia Oryzae), Udbatti (Eplielis Oryzae), Kani (Sphecelothica Sp.) and Kevda (Xantho-monas Sp.). These diseases cause extensive damage to crops.

Karpa, the blast of rice (Piricularia Oryzae) is the most destructive of these. Damage on account of this disease is approximately estimated to be in the neighbourhood of 15 to 20 per cent of the crop. No permanent method of control has been devised so far. Seed treatment and spraying of the crop with bordeaux mixture 3:3:50 has been recommended as a temporary measure of control and the work of evolving blast-resistant varieties as a permanent method of control is in progress.

Kani or Smut of rala (Sphecelothica Sp.) at times causes a heavy damage varying between 20 and 30 per cent of the crop. The disease can be totally prevented by steeping the seed in two per cent copper sulphate solution for ten minutes. However, nowadays treating the seed with 200-300 mesh-fine sulphur at a rate of four ounces per 60 lbs. of seed, is more in vogue.

Kani (Sphecelothica Sp.) and Karpa (Piricularia Oryzae) of nagli are the other two diseases prevalent in the district. Of these, kani causes appreciable damage which can be easily prevented by treating the seed with sulphur before sowing it.

Of Pulses.

Mar, the Wilt disease of gram (Fusarium Oxysporium) causes extensive damage and has not been amenable to any direct control measures so far. Plants all over the field dry up generally at the flowering stage or a little later. Resistant varieties such as Nagpur 352 and Dohad are being evolved. The only remedy for the disease is to uproot affected plants and burn them.

Of Vegetables.

Bhuri, the Powdery Mildew (Erysiphe) on cucurbit is universal. It can be easily controlled by dusting sulphur.

Kevda, the Yellow Vein Mosaic of bhendi is a virus disease and both rabi and kharif crops suffer from it. It is a highly infectious disease transmitted by white flies and may damage the crop to the extent of forty to cent per cent. To avoid mosaic, affected plants are removed and burnt for checking virus. It is recommended that bhendi should not be sown in March and April. Breeding the disease-resistant types of bhendi is the. only reliable method of controlling this disease and the work in this direction is already in progress.

Mar (Verticillium dahliae) and Tikka (Cercospora Sp.) are common diseases of brinjal. Tikka can be controlled by spraying bordeaux mixture in the proportion of 3:3:50, whereas mar cannot be controlled by any direct measure. Hence growers take resistant varieties of the crop.

Pan Valne, leaf curl of tomato (virus) is a very serious virus disease transmitted by white flies. No control methods have been devised as yet.

Of Fruits.

Areca-nut.

Koleroga of areca-nut (Phytophthora Arecae) is a very serious disease victimising areca-nut produced all along the coastal line of the district. Immature nuts begin to drop down in large numbers in June. The disease attacks the ripening nuts in bunches and causes shedding after the fallen nuts rot. The overall damage is estimated to vary between 15 and 25 per cent.

The Agriculture Department advises that the following steps may be taken to bring the disease under control; firstly, removal and destruction of dead and dying tree tops and a clean cultivation; secondly, application of bordeaux mixture in the proportion of 5:5:50 to bunches before the onset of the monsoon with particular emphasis on trees located in the vicinity of dead and dying trees of the previous season; thirdly tying up of bunches with grass hoods previously soaked in bordeaux mixture, immediately after they are sprayed; and finally, vigilance over the garden and immediate spraying of hunches which may show dropping towards the end of August or September. Trees surrounding these foci of infection should also receive spraying.

Band disease of areca-nut is attributed to physiological causes. The estimated damage ranges between 35 and 40 per cent of the crop. No control measures have so far been recommended.

Mool-kunjne or Anaberoga, the foot-rot of areca-nut (Ganoderma Lucidum) is of late reported to be operating on a wide scale in the district. Death of affected plants occurs within one or two weeks since the onset of the disease; for thereafter the recovery is almost impossible. Preventive measures such as cutting down affected plants and burning down the remains should form an important part of measures to control the disease.

Of Mango.

Bhuri, the Powdery Mildew of mango (Oidium Magmterde) occurs on blossoms and resuls in poor setting of fruits. When young fruits are attacked, they wither and drop down. Bhuri is usually accompanied by jassid hoppers, an insect pest. Both cause serious damage to the crop. However, they can be effectively controlled by dusting the blossoms with a mixture of 200 mesh-fine sulphur and five per cent DDT dust in the proportion of 1:1 or 1:2, depending upon severity of jassid attack. Dusting should be given first, when blossom is complete and followed by second application after a fortnight. Nirmally, two dustings should suffice, but sometimes a third one may also he found necessary. The cost of dusting works out to about two rupees per tree.

Bandgul or Loranthus of mango is a flowering parasite which attacks branches of mango trees by sending haustoria inside the tissues to derive nutrition. Affected branches do not thrive well and their yield is poor. This parasite spreads from tree to tree through seeds. Fruits which are red and have sweet sticky seeds are eaten by birds and, if by chance these are deposited on branches, the seed germinates and a new plant of Loranthus comes up. The only means of effective control is to cut down the parasite below the point of attachment along with the mango branch.

Of Coconut.

Shenda Kujne, the Bud-Rot disease of coconut (Phytophthora) is prevalent in the district and causes extensive damage to the coconut cultivation. In this case, leaves begin to drop off. The terminal bud rots and ultimately the plant is killed. The only remedy is to cut down the affected plants and burn them. If only outer sheaths are affected, these may be removed and the crown sprayed with one per cent bordeaux mixture. If the disease is far advanced and the recovery impossible, the entire crown may be cut down and burnt. As a measure to guard against the spread of disease, trees surrounding "those affected should also be sprayed with one per cent bordeaux mixture.

Cheek Vahane, the Stem-Bleeding disease of coconut is very common in the district, the extent of damage depending upon the age of the palm and conditions under which it is grown. It kills young palms, though such cases are a rare phenomenon. The Agriculture Department advises, as control measures, that infected tissues should be chiselled out and the cut surface should then be painted with coal, tar or bordeaux paste.

Of Other Fruits

Mar, the Panama disease of banana is fierce and the son variety is highly susceptible to it. Thus, growers take the basarai variety more commonly, as it is resistant to the disease. Kevada, Chlorosis of banana, (Virus) is caused by a virus. The affected plants show a somewhat bushy appearance and have a stunted growth. Severely diseased plants hardly yield fruits, while even in other cases, the yield is of a poor quality. The disease is transmitted by a specie of aphids. Among the disease control measures can be included burning all affected plants in the garden, preventing export of diseased suckers to other places and planting disease-free suckers obtained from a healthy garden.

Khaira, the Guava Canker affects fruits, which remain small and stunted. The marketable value of guavas is lowered because of the poor appearance of cankers. Spraying with bordeaux mixture 3:3:50, when fruits are yourtg, affords good protection.

Kevada, the Mosaic of Papaya (Virus) is caused by a virus, The Papaya Mosaic is transmitted by five different species of aphids and causes damage at such an alarming late that its cultivation is almost threatened with extermination. The only possible method to control the disease is to observe a closed season by avoiding to grow the crop for a year so as to make the locality virus-free. In order to ensure success, it is essential that this is done on a community basis. Besides, infected plants should be destroyed as soon as they begin to appear.

Mool Kujne, the Foot-Rot of papaya (Pythium Aphaniderma tium) is operative mostly during the rainy season and affects such gardens as are liable to be water-logged or ill-drained. The disease is caused by a fungus parasite. Control measures consist of such preventive practices as avoiding water-logging and preventing the destruction of affected plants.

Khaira, the Canker of Kagdi Lemon (Xanthomonas Citri) is a bacterical disease of common occurrence. Generally, all parts above the ground are affected and fruits become disfigured. This adversely affects their marketable value. There are no measures to control this disease completely. However, it can, to some extent, be mitigated by cutting down and burning affected stems, twigs and leaves generally in May and by thoroughly spraying a bordeaux mixture in the proportion of 3:3:50.

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