Weed protection for rice seedlings
TODAY Pakistan is facing two major disasters: one is the coronavirus and the other is the desert locust. To fight coronavirus, a lot of awareness has been created along with standard operating procedures (SOP) using print and electronic media. Unfortunately, to protect agriculture from the ravages of locusts neither awareness nor any SOPs have so far been issued for the growers, particularly in Sindh and Balochistan, both at the federal and provincial level.
Our television is, almost daily, showing swarms of locusts invading crops in different parts of Sindh and Punjab. Sindh is demanding aerial spray and aircraft to contain invading locust swarms in the green belt (cropped area) whereas the federal government seems to be reluctant to control locust swarms other than in the deserts of Sindh, Punjab and Balochistan. The reason behind this reluctance is probably the 18th Amendment under which agriculture, and therefore its protection, comes under the jurisdiction of the provinces.
A survey of cotton growers in Nara desert cotton belt of district Sukkur, Khairpur and Sanghar and rice growers of district Shikarpur, Jacobabad and Larkana has indicated that indirect damage of the locust threat may be more than the actual damage which is caused by the locust attack to the kharif crops. The reason is the hovering locust swarms over almost entire of Sindh and their sporadic landing on standing vegetables, lucerne, maize, jowar bajra, sesbania, green vegetation and trees.
Locally known as kandero, the Alhagi weed becomes so thorny after its leaves dry that it is difficult for locust to penetrate through
Instead of ground support from the provincial and federal governments, the growers have to resort to beating drums to keeping the locusts at bay. Apprehensive about the damage to crops that are grown with costly seeds, cotton and rice growers are considering delaying the sowing of these crops. Cotton is sown in Upper Sindh in May and rice seedlings (rice nursery) are sown after May 15 and transplanted up to July 15. If the cotton crop is sown late, it is at risk from the pink bollworm and rice crop can be damaged by white back plant hoppers, leaf folders and stem borers.
However, the late transplantation of the rice crop in upper Sindh and Balochistan can be avoided through the protection of seedlings. Saving one acre of rice seedlings from locust attack means saving 35 to 45 acres of rice crop that is grown from the transplanted seedlings.
A way of protecting rice seedlings from the locust attack is by covering the seedbed with a thorny weed Alhagi maurorum (camelthorn) Family-Fabaceae, locally known as kandero. After its leaves dry, the weed plant becomes so thorny that is difficult for an insect the size of a locust to penetrate through thus giving full protection to the seedlings till they are transplanted. This is a common weed that grows among gram and wheat crops in the riverine belt but is also found in abundance in rice-growing areas on bunds of fields, watercourses, irrigation canals and desert areas.
When the matter of using the thorny kandero weed as a weapon against swarming locusts was discussed with a progressive grower of Shikarpur, Mr Jameel Ahmad Siddiqui, he apprised this scribe that in years of dry summer spells, he uses it to cover the rice seedling bed to provide them shade and air against the scorching heatwave.
Accordingly, to avoid a delay in transplanting of the rice crop in the apprehension of the locust invasion, it is suggested that rice growers cover the seedling beds with the thorny kandero weed after sowing or germination. To persuade growers for this method of nonchemical protection of seedlings, the Provincial Agriculture (extension) Department of Sindh and Balochistan should use print and electronic media besides using its field force.
Review of literature has indicated that Alhagi maurorum (camel thorn) is a shrub native to Western Europe and Central Asia that has become an agricultural weed in other parts of the world. Its medicinal value can be gauged from the fact that studies have shown 66 per cent of patients treated with Alhagi extracts for four weeks expulsed urinary tract stone because it aqueous extract reduces the calcium oxalate in the kidney stone.
The writer is an ex-entomologist of Department of Plant Protection, Karachi, and President of Agriwatch Society of Pakistan
Published in Dawn, The Business and Finance Weekly, May 18th , 2020