Cotton, a commercial crop and backbone of the textile industry is heaven for insect-pests. More than 90 per cent of the fibres is obtained from cotton crop alone. This crop is the backbone of the textile industry, where 80 per cent of the raw material is obtained from it.
Due to insect and diseases infestation, both quality and the quantity are greatly reduced in various ways e.g. premature boll opening results in lint damage and discolouration and immature fibre.
Cotton farmer from Haryana and Punjab is facing problems from the growing menace of white fly that cripples the growth of cotton plant. This has resulted in the yield of BT cotton on their farm dropping.
The farm scientists (Dr Saini) of Haryana University has advised the farmers for constant monitoring of BT cotton crops against whitefly and sucking pests and spray the recommended insecticide when weather is clear. He said that due to humid weather, there may be attack of whitefly and incidence of bacterial leaf blight.
He said an effective management of this important disease is possible by development of resistant varieties.
The three states (Haryana, Punjab and Rajasthan) count for about 12 per cent of the country’s total cotton production.
In the last two years, the average yield in Haryana farmer has dropped by about 20 per cent due to whitefly. In addition, the cultivation costs have gone up considerably, as they have to spray at least four to five insecticides to keep the white fly under check.
The emergence of sucking pests such as white fly, mealy bug and jassid are posing threat to cotton crop across all over country.
Though insecticide costs that accounts for 8-10 per cent of the cultivation costs are on the rise, labour shortage and rising wages are a major worry for cotton growers.
Cotton Whitefly (Scientific Name : Bemisia tabaci)
Host Range : Polyphagous insect. Some of the hosts are puthkanda, gutpatni, cabbage, cauliflower, sarson, toria, melon, potato, brinjal and okra.
Damaging Stage : Nymphs and Adults.
Identification
Adults : Adults are 1.0 to 1.5 mm long, yellowish in colour and dusted with white waxy powder. Wings are pure white.
Nymphs : Nymphs are yellowish white.
Seasonal History : The whitefly infestation remains in cotton more or less throughout the cotton season but the maximum damage in cotton is done during August-September. Higher population has been noticed in dry weather conditions which encourage its population build up.
Economic Threshold : Average six to eight nymphs per leaf. Count the population from three leaves (one each from top, middle and bottom) per plant and take observation at least from 10 plants from the field.
Nature of Damage : Damage is done by sucking the cell sap from the leaves resulting in loss of vitality of the plant. Normal photosynthesis is affected due to growth of sooty mould on honeydew deposited on upper surface of the leaves, consequently the growth of the plant and yield are affected. Cotton white fly also transmits the cotton leaf curl virus and the veins of diseased leaves get thickened becoming cup shaped (up side).
Management : Spray the crop with 250-350 ml dimethoate (Rogor) 30 EC or 300-400 ml oxydemeton-methyl (Metasystox) 25 EC or formothion (Anthio) 25 EC or 40 ml imidacloprid (Confidor) 200 SL, 40 g thiomethoxam (Aktara) 25 WG after mixing in 120-150 litre of water.
Their management can be accomplished best through integration of various approaches. These involve the choice of suitable variety, the crop rotation to be followed, cultural practices, proper nutrient and water management.
You should give proper time to natural enemies of whitely to control their population before spraying pesticides. It is not possible to eliminate all population of whitefly. You can reduce their population by 70 percent by collective approaches. All farmer of neighbours’ farm should effort collectively to reduce population of whitefly. You can graze yellow board with gum as whitefly attract toward yellow colour.
Note : The higher population of whitefly has been noticed in dry weather conditions during August-September. Avoid excessive use of pesticides. Try to spray “neem” products to control whitefly as it reduces reproduction of whitefly. You can spray triazophos/acephate to control whitefly after advice of farmer scientists. Monitor the crop for diseases every week.
Hindi
जिलेके जागरूक किसानों ने कपास के अच्छे भाव देखते हुए इस सफेद सोना पर दांव खेला है। यहीं कारण है कि इस बार अनुमानित लक्ष्य से कहीं अधिक हेक्टेयर में कपास की फसल खड़ी है।
हालांकि इससे पहले माना जा रहा था कि बीटी कॉटन पर किसी तरह की बीमारी नहीं लगती। सफेद मक्खी के प्रकोप से किसानाें के चेहरे मुरझा उठे हैं। कृषि विशेषज्ञाें के अनुसार सफेद मक्खी के कारण औसत उत्पादन गिरना लाजिमी है। कृषि विभाग का मानना है कि सफेद मक्खी का प्रकोप तो है, लेकिन 10 से 20 फीसदी ही नुकसान होगा।
कृषि उपनिदेशक डा. अनूप सिंह ने बताया कि बीटी कॉटन पर गुलाबी, चितकबरी, अमेरिकन सुंडी इत्यादि की बीमारी नहीं लगती, लेकिन बदले मौसम के अनुरूप सफेद मक्खी का प्रकोप इस फसल को नुकसान पहुंचाता है।
कपास में इन दिनों वाइट फ्लाई का प्रकोप रहता है। इसको एक सही मात्रा में कीटनाशक डालकर रोकथाम की जा सकती है। कई बार किसान कृषि विभाग के सुझाव नहीं मानते हैं और अलग-अलग तरीके के कीटनाशक गलत मात्र में स्प्रे कर देते हैं, जिसके कारण कपास की फसल नष्ट होने की संभावना कहीं अधिक बढ़ जाती है।
