FAQ: Pest management

58. Does no-till change the weed composition?
Yes continuous no till conditions enhance the population of perennial weeds but by application of pre-seeding herbicides we can kill them prior to seeding. The broad leaf weeds also increase in ZT field upto some extent, but they can be easily controlled by herbicides.

59. Does ZT in any way affect the Phalaris minor population over years?
Yes, it reduces the population of Phalaris minor. The seeds of the Phalaris minor germinate only when it lies in upper 5 cm soil layer Therefore, in no till field, seeds buried in deeper soil layers do not germinate. Phalaris minor seeds present in surface layers germinate when they get moisture at the time of first irrigation. Study revealed that on an average 30-40 % less Phalaris minor population is observed in no till condition compared to conventional tillage. It is observed that population of broad leaf weeds increases in no-till system.

60. Do intercultural operations in zero till in any way adversely affect the benefits of no till system?
Although no-till systems rely on use of herbicides but intercultural operations such as to mechanically control weed or band place fertilizer nutrients in no way adversely affects the benefits accruing from no-till / zero till system. Rather it may reduce the costs of cultivation by cutting back on herbicide use.

61. What measures are taken to control weeds?
Fields can be freed of existing weeds by application of pre-seeding herbicides, two days before sowing of the crops. In zero-till field because of less disturbance of the soil, germination of Phalaris minor is low compared to conventional tillage. But if the weed population is above the economic thresh hold value then grassy herbicides such as Isoproturon, Leader, Topik and Puma super should be applied 30-35 days after sowing. For the control of broad leaf weeds, 2,4-D or Algrip should be sprayed at 35-40 days after planting.

62. How do I remove weeds of rice crops before planting wheat?
Perennial weeds hinder the smooth running of ZT machine if present at large density. A pre-seeding application of a broad-spectrum herbicide (Round up/ Gramoxon) kills these weeds. Annual weeds of rice die towards the maturity of rice or in winter season.

63. Is Glyphosate use necessary before wheat planting?
No, the application of Roundup is only necessary in the situations, where weeds have emerged before planting wheat as in late sown conditions. If wheat is sown timely in residual moisture of the previous rice crop, weeds do not emerge before wheat planting and there is no need to apply Roundup. If Roundup (Glyphosate) is expensive, farmers can opt for a shallow tillage to kill the weeds.

64. Does rodent population increases in ZT plots with stubbles?
Farmers often complain about increased rodent attack; however several research studies undertaken on the issue don’t prove this contention of the farmers. According to them it is a general problem not specific to no-till plots. If rodent menace is feared, traps and chemical control measure should be adopted by the farmers as a group.

65. Is it true that intensity of stem borer attack does not increase in rice-wheat crops grown in no-till system?
Yes, Stem borers is a major pest of the rice crop. It is commonly apprehended that the pest will move to wheat planted in no-till system. It has been observed that stem borers common to rice crops donot survive the winter season and hence there is no increase in attack of this pest in wheat crop.

How do we stop the birds picking seeds from the open slits?
Generally there is no damage of birds because placement of seed in the slit is beyond their reach. To stop the bird damage we can treat the seed with cow dung. Treatment of seed with endosulfon is not advocated as it may kill the birds.