Agrochemical Knowledge Center | Crop Guides, Deficiency, Spray Schedule

Nutrient	Visual Symptoms	Crops Most Affected	Corrective Product	Apply
Zinc (Zn)	Interveinal chlorosis on young leaves, small leaf size, shortened internodes, "little leaf" in citrus	Grapes, Citrus, Rice, Maize, Pomegranate	Zinc EDTA 12% or Zinc Sulphate 33%	Foliar spray 0.5–1% or soil drench
Iron (Fe)	Yellowing between veins on young leaves, veins remain green (interveinal chlorosis), most severe on new growth	Grapes, Groundnut, Citrus, Soybean	Iron EDDHA 6% or Iron EDTA 12%	Soil drench (EDDHA) or foliar (EDTA)
Boron (B)	Distorted growing tips, hollow stem in cauliflower, poor fruit set, cracking in celery, "witches broom"	Cotton, Sunflower, Cauliflower, Grapes	Borax 11% B or Boric Acid 17.5%	Foliar 0.1–0.3% at flowering
Calcium (Ca)	Blossom end rot in tomato, tip burn in lettuce, bitter pit in apple, poor root growth	Tomato, Apple, Lettuce, Capsicum	Calcium Nitrate 15.5-0-0 or Calcium EDTA	Fertigation or foliar spray 0.5–1%
Magnesium (Mg)	Interveinal chlorosis on older/middle leaves, leaves turn yellow-brown from edges, veins remain green	Potatoes, Tomato, Citrus, Grapes	Magnesium Sulphate 9.9% Mg	Foliar 1–2% or fertigation
Nitrogen (N)	Uniform yellowing of older leaves progressing upward, stunted growth, pale green colour overall	All crops — most common deficiency	NPK 30:10:10 or Urea 46%	Basal or fertigation
Phosphorus (P)	Purple/reddish colour on undersides of leaves, dark green foliage, delayed maturity, poor root development	Maize, Wheat, Potato, Tomato	MAP 12:61:00 or MKP 0:52:34	Basal application or fertigation
Potassium (K)	Scorching/browning of leaf tips and margins starting on older leaves, weak stems, poor fruit quality	Potato, Banana, Tomato, Cotton	SOP 0:0:50 or MKP 0:52:34	Fertigation or foliar 1%
Manganese (Mn)	Interveinal chlorosis on young leaves (similar to Fe but less intense), grey speckling in oats	Oats, Soybean, Sugar beet	Manganese EDTA 12% or Mn Sulphate	Foliar 0.3–0.5%
Sulphur (S)	Uniform yellowing of young leaves (unlike N which starts on old leaves), poor protein synthesis	Mustard, Onion, Garlic, Pulses	Gypsum 32% CaSO₄ or Ammonium Sulphate	Basal soil application
Copper (Cu)	Wilting of young leaves, bluish-green discolouration, dieback of growing tips, poor grain set	Wheat, Barley, Citrus, Cereals	Copper EDTA 12% or Copper Sulphate 25%	Foliar 0.2–0.5%
Molybdenum (Mo)	Cupping and marginal scorch of leaves, whiptail in cauliflower, affects N fixation in legumes	Cauliflower, Legumes, Brassica	Sodium Molybdate 39% Mo	Foliar spray 0.01–0.05%

📅 Crop Spray Schedules

Recommended programs from vegetative to harvest — select your crop

Stage	Product	Dose	Purpose
Dormancy Break	Hydrogen Cyanamide 50% SL	1.5–2.5%	Uniform bud break
Young Shoot	NPK 30:10:10	3–4 g/L	Vegetative push
Pre-Flowering	Boron Ethanolamine 10%	1 ml/L	Improve fruit set
Flowering	GA3 40 WSG	10–15 ppm	Berry elongation
Fruit Set	Calcium Nitrate 4-0-0-26Ca	3–4 g/L	Cell wall strength
Berry Dev.	NPK 13:0:45	3–4 g/L	Sugar accumulation
Pre-Harvest	SOP 0:0:50	4–5 g/L	Colour, quality
Post-Harvest	Zinc EDTA 12% + Iron EDTA 12%	1 ml + 1 ml /L	Reserve nutrition

Stage	Product	Dose	Purpose
Nursery	NPK 19:19:19 + TE	2 g/L	Balanced seedling nutrition
Transplanting	MAP 12:61:00	3 g/L	Root establishment
Vegetative	NPK 30:10:10	3–4 g/L	Leaf area development
Pre-Flowering	Boron 10%	1 ml/L	Pollen viability
Flowering	Calcium Nitrate + NPK 18:18:18	2+2 g/L	Prevent BER, fruit set
Fruit Dev.	NPK 13:0:45	4 g/L	Size and firmness
Pre-Harvest	SOP	3–4 g/L	Colour and shelf life

Stage	Product	Dose	Purpose
Sowing	Thiamethoxam 70% FS	3 ml/kg seed	Sucking pest protection
15–20 DAS	Zinc Sulphate 33%	2 g/L foliar	Early zinc nutrition
Square	NPK 19:19:19	3 g/L	Balanced nutrition
Flowering	Boric Acid 17.5%	1 g/L	Boll set improvement
Boll Dev.	NPK 0:0:50	4 g/L	Fibre quality
Boll Opening	Ethephon 39% SL	0.5–1 ml/L	Uniform boll opening

Stage	Product	Dose	Purpose
Sowing	Zinc Sulphate 33%	25 kg/ha soil	Zinc soil correction
CRI Stage	Urea 46%	Split dose	Nitrogen top dressing
Tillering	NPK 28:14:14	3 g/L foliar	Tiller promotion
Jointing	Sulphur 80% WDG	2 g/L	Protein synthesis
Boot	Manganese EDTA 12%	1 ml/L	Prevent yield loss
Grain Fill	NPK 13:0:45	3 g/L	Grain weight

Stage	Product	Dose	Purpose
Nursery	Zinc Sulphate	10 kg/ha	Khaira disease prevention
Transplanting	DAP 18:46:00	Basal	Root establishment
Tillering	Urea 46%	Top dressing	Maximum tillering
PI Stage	NPK 13:0:45	3 g/L	Panicle initiation
Flowering	Boron 10%	1 ml/L	Pollen viability
Grain Dev.	SOP 0:0:50	3 g/L	Grain filling

❓ Frequently Asked Questions

Common technical questions answered by our agronomists

What is the difference between EDTA and EDDHA chelated micronutrients? +

EDTA (Ethylenediaminetetraacetic acid) chelates are stable in pH 4–7 and are best applied as foliar sprays or in acidic soils. EDDHA (Ethylenediamine-N,N'-bis(2-hydroxyphenylacetic acid)) remains stable up to pH 9 and is the preferred choice for iron correction via soil application in alkaline/calcareous soils common in India. EDDHA is more expensive but far more effective for soil-applied iron.

When should I use foliar spray vs fertigation for micronutrients? +

Foliar spray is faster — nutrients are absorbed within 24–48 hours and are ideal for correcting acute deficiencies during the crop season. Use chelated forms (EDTA/DTPA) for foliar application. Fertigation via drip gives a slower, sustained supply and is more efficient for planned nutrition programs. Use higher-grade water-soluble products for drip. Soil pH greatly affects nutrient availability in fertigation.

Can I mix fungicides and micronutrients in the same tank? +

Most EDTA chelated micronutrients are compatible with common fungicides (mancozeb, carbendazim, propiconazole). However, always do a jar test before large-scale mixing: add products separately to water and observe for precipitation, layering or colour change. Avoid mixing alkaline products (copper-based fungicides, lime sulphur) with acidic micronutrient solutions. Never mix more than 3 products without testing.

What NPK ratio is best for flowering stage? +

For the flowering stage, use high-phosphorus NPK grades like 12:61:00 (MAP), 13:40:13, or 00:52:34 (MKP). Phosphorus promotes root development, energy transfer and flowering. Reduce nitrogen (high N delays flowering). Add boron at 0.1% to improve pollen viability and fruit set. After fruit set, switch to high-K grades like 13:00:45 or 00:00:50 for fruit development.

What is the correct time to spray agrochemicals? +

Best time is early morning (6–9 AM) or late evening (4–7 PM) when temperatures are below 32°C. Avoid spraying during midday heat as it increases evaporation and phytotoxicity risk. Do not spray when rain is expected within 2–4 hours. For systemic products, ensure leaves are dry before spraying. Some products (GA3, Ethephon) are temperature-sensitive — always follow label guidelines.

How do I calculate EC for hydroponic nutrient solution? +

EC (Electrical Conductivity) measures total dissolved salts in nutrient solution. Target EC varies by crop: leafy greens 1.2–2.0 mS/cm, tomato 2.5–5.0, strawberry 1.5–2.5. Dissolve WSF grade fertilizers (e.g. NPK 19:19:19 + calcium nitrate + magnesium sulphate) in water and measure with EC meter. pH should be 5.5–6.5. Adjust EC by diluting with water (if too high) or adding more nutrient concentrate (if too low).

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