'Cyclone Amphan can increase Fall Armyworm infestation'

One of the main reason FAW outbreak occurred in Manipur in May, 2019 was due to cyclone Fani.

The present rate of Fall Armyworm (FAW) infestation in maize is very less comparing to last year's attack, but the crops may be damaged at a large scale if necessary precautionary measures are not taken up.

This was stated by Associate professor, College of Agriculture (CAU), Entomology, Central Agricultural University, Imphal, Khumukcham Ibohal, during an interaction with the Imphal Free Press.

The state government is giving extra intervention in agricultural sector to prevent from food insecurity caused by impact of COVID-19 pandemic. Amidst this critical situation, many farmers are facing the brunt of FAW infestation in their maize crops, he added.

Ibohal said the outbreak of FAW infestation in maize occurred last year in Manipur for the first time. Compared to last year, the level of damage caused by FAW in the maize crop is very less so far; however, farmers should not take the problem of FAW infestation very lightly, he cautioned.

One of the main reason FAW outbreak occurred last year was due to cyclone Fani. Besides, previous year's outbreak also occurred in the month of May. “As such, the farmers should take the present infestation issue very seriously as many parts of India are being hit hard by cyclone Amphan," he added.

“FAW, a native to tropical and sub-tropical regions of America, started spreading to Africa in 2016 and then to Asia. The report of infestation in India was first recorded in 2018. More than 20 states of India have been infested by this pest,” he informed.

FAW, a nocturnal species can fly 100 km per hour at night. The female moth of the pest have the ability to lay around 1500-2000 eggs, he added.

Besides their capacity to travel fast, cyclones also help them to enhance their normal speed, he added and suggested farmers to be very cautious that FAW outbreak may by recur this year by the cyclone Amphan, he added.

Stating about the rate of infestation, he said that the pest damaged 80 percent of maize crop last year in the state. The present infestation is less till date comparing to previous year. But in some places, it has caused destruction in a large scale, he added.

As per a field survey conducted by CAU, Imphal some days ago, two Sangam (local unit) of land in Leimaram, Bishnupur were completely damaged by the pest. 

Altogether, around 60 percent of the maize fields in various places of Chandel were destroyed, he added and continued that production in five hectare of maize farm in Huikap, Andro and one ‘Sangam’ (local unit of land) in Moirang were also lost.

He said that the pest has two biotypes such as maize biotype and rice biotype. The maize biotype consists of 93.8 percent and rice of 5.4 percent. The composition of biotype proves that FAW usually do not attack rice crops.

Research conducted by CAU with the help of National Bureau of Agricultural Insect Resources, Bengaluru, Karnataka (report of research was sent in this institution) also found that the pest does not infest in rice, he added.

Stating about the precautionary measures undertaken to prevent from FAW, he said from last year's experience of the outbreak, CAU has developed an 'Effective management practices for FAW', but many farmers are not aware of it.

The practices are quite useful and if farmers adopt them sincerely, their crops can be successfully protected from this dangerous moth, he added.

Explaining about the practices, he said at early crop stage, Neem Formulation either Multineem (Azadirachtin 300 ppm) of 75 ml per 15ml of water or Pestoneem (Azadirachtin 1500 ppm) of 45 ml per 15 litres of water, or Spinetoram 11.7SC of 10 ml per 15 litres or application of Green Pacer of 45 ml per 15 litres of water can be applied at the base of plant.

For late crop stage, Emamectin Benzoate 5SG of 5 gm per 15 litres of water or Chlorantraniliprole 18.5 SC of 4.5-5 ml per 15 litres of water or spray Chlorpyrifos 20 EC of 45 ml per 15 litres of water can be applied on all the bunds during morning 7-8 a.m. in order to kill all the larvae settling during day time, he said.  If available, apply pheromone trap of five to seven traps at the ‘Sangam’ (local unit of land).

He continued that at productive stage, one can also apply Chlorpyrifos 20 EC of 45 ml per 15 litres of water on all the bunds during 7-8 a.m. If available, one can install five to seven pheromone traps in one ‘Sangam’ (local unit of land)  by maintaining a space of between 10 to 15 meters, he advised.

Explaining about period during which the mentioned practices can be applied, he said it can be adopted if pests are found infesting on five plants in every 100 plants at the stage of budding till 14 days, and if the crop is damaged at the rate of five to 10 plants in every 100 crops when it attains the stage of two to four weeks.

From four to seven weeks, the infestation rate should be 10 to 20 plants in every 100 plants. For the period of seven weeks to flowering, the attack rate should be 20 plants in every 100 plants. From flowering till maturity, it should be five plants per 100 plants.

He appealed all the maize cultivators to check their crop regularly to abstain from facing such havoc.

First Published:May 25, 2020, 1:24 a.m.