A weed killer spray for fields only works as well as the way it is applied. Start with calibration: fill your 15-litre knapsack, spray a measured patch, and see how many pumps cover an acre. That tells you the water volume, and the label dose per pump or per acre tells you how much product to add. Use a flat-fan nozzle for herbicides, keep the boom height steady, and walk at an even pace. Spray in calm weather, in the cool of the morning or late afternoon, onto dry foliage, and avoid spraying if rain is likely soon after, unless the label says it is rainfast. Never spray near ponds, canals or wells. Mix the product in a small amount of water first, then top up, and agitate as you go. Wear gloves, goggles, a mask and full-sleeved clothing, and wash with soap afterwards. Rinse the sprayer well, ideally one reserved for herbicides. Gramiti herbicide pages show the dose per litre, per pump and per acre wherever the label gives them, with free delivery above ₹699. For help, email customercare@gramiti.com.