Rain deficit moisture stress management in vegtables

When the monsoon is delayed by 15 days

a) Vegetable varieties suitable for growing under such condition

b) Production strategies

• Grow short duration varieties as suggested in above table
• Raise crop on ridge-furrow or furrow irrigated raised bed planting system
• Two spraying of water soluble mixed fertilizers (19:19:19 NPK) @ 5 - 7 g/lit, 30 days after crop establishment ensure early and vigorous plant growth
• Ensure staking of crop wherever required.

c) Plant protection strategies : Recommended plant protection measures for control of pests & diseases may be followed.

When the monsoon is delayed by 30 days

a) Vegetable varieties suitable for growing under such condition

Production strategies

• Use of organic mulch such as paddy straw, dry grass, etc @ 7 - 10 tones/ha
• Use of organic manures (FYM 15 tones/ha or vermicompost 10 tones/ha) to enhance water holding capacity of soil
• Ensure life saving irrigation at least during critical growth stages such as active growth, flowering and fruit enlargement. If there is water shortage, alternate furrow irrigation should be practice
• Do not allow weeds to grow during plant’s early growth stage
• Perform tillage operations only in upper 5cm soil layer . Plant protection strategies Sucking insect pest viz. jassids, whitefly, Aphids, thrips, mites, etc may be a major problem. In drought condition, chance of occurrence of diseases in vegetables is less (except viral diseases).

For management of sucking pests, the following strategies may be followed:

• Seed treatment with imidacloprid or Thiomethoxam @ 3 - 5gm/kg seed
• Foliar spray of imidacloprid 17.852 @ 0.55 ml/L, Thiomethoxam 25 wG @ 0.35g/L or Thiocloprid 21.7 SC @ 0.65ml/L.
• For mites - Abametin @ 0.5 ml/L,Spiromesifer @1 ml/L, Chlorofenpyr @1ml/L, Poersite 2 - 3 ml/L or Fenzaquin @2 ml/L
• Botanical insecticides - Neem based insecticide @ 5 ml/L
• Bio - agents - Verticellium lecani - 5 g/L.
• For Mealy bugs - Chlorpyriphos 20EC @ 2 ml/L or Imidacloprid @ 05 ml/L.
• For sporadic incidence of Lepidopteran pest (Caterpillar) - Indoxacorb 0.5 ml/L, Emamectin benzoate @ 0.35 gm/L or Flubendamide @ 0.5 ml/L

Under erratic/ unpredictable/inconsistent/ irregular rainfall

Production strategies

• Grow crop on ridge - furrow (25 - 30 cm high) or furrow irrigated raised bed (90 cm wide and 20 cm high) planting system to avoid water logging situation
• Grow vegetable crops and varieties that can sustained both under scanty and heavy rainfall condition as suggested in table above
• Train cucurbit vegetables over bower system
• Ensure life saving irrigation at least during critical growth stages such as active growth, flowering and fruit enlargement.
• Do not allow weeds to grow during plant’s early growth stage.

Onion

In onion only kharif crop (20 % area) is rain-fed. Rabi onion, which is the main crop (60% area) and late kharif (20% area) are grown as irrigated crops. Thus, drought/rainfall deficit has relevance mainly to kharif crop. Kharif crop of onion is grown mainly in Maharashtra, Karnataka, Gujarat and some parts of Rajasthan.

If monsoon delayed by 15 days :

This may not have much effect on the kharif onion as this crop can be transplanted from July to August. The nursery raising will be rather easier, as onion seedlings are difficult to be raised under rains. The following strategies are suggested in this situation.

• Varieties having wider adaptability (suitable for kharf as well as late kharif ) namely Bhima Super, Bhima Raj, Bhima Red, Bhima Shubra, Agrifound Dark Red, Arka Kalyan, Arka Pragati, Baswant 780 and Phule Samarth may be grown.
• Nursery may be raised during second week of June in such a way that seedling of about 35 - 50 days could be transplanted.
• Raise seedlings on a raised bed with drip or micro sprinkler irrigation syst em to use available irrigation water judiciously. In case, drip irrigation facility is not available, apply irrigation water through water sprinkler cans.
• Minimum three to four irrigations need to be given in nursery.
• Seedlings should be protected by prov iding partial shade nets.
• Apply stubble mulch (paddy straw) until seed germination to avoid evaporation.
• Apply well decomposed organic manures @ 0.5t / 1000 sq m. 8. In case of poor seedling growth, foliar application of water soluble NPK fertilizer (for exa mple 5g/liter 19:19:19 NPK) may be given for quick recovery.

If monsoon delayed by 30 days

• The strategies as listed above should be followed.
• The other alternative can be to go for direct seeding of onion (Seed rate 8 - 9 kg/ha) on raised bed with drip or sprinkler irrigation system as this crop matures 1 month earlier than the seedling transplanted crop.
• Use sets if available for raising kharif crop as this crop matures 45 days earlier than the seedling transplanted crop.

Rain deficit at vegetative phase

Three to four irrigations are essential during active vegetative growth stage depending upon soil type i. e. at establishment stage (10 - 20 DAT), active vegetative growth stage (30 - 40 DAT) and bulb initiation stage (40 - 50 DAT). To cope up with rain deficit at this stage the following advisory may work.

• Raise crop on raised beds with drip irrigation.
• Harvest rain water by making storage ponds which will help to provide two to three life saving irrigations during drought. Irrigation water should be applied as per soil moisture level and crop requirement only.
• Spray anti - transparent Kaolinite @ 5% to reduce water loss through transpiration as per requirement.
• Cover soil surface with organic mulch such as paddy/wheat straw, or fodder to reduce evaporation.
• In case of poor crop growth, foliar application of water soluble NPK fertilizer (for example 5g/liter 19:19:19 NPK) may be given for quick recovery.
• Foliar application of sulphur 85% WP @ 1.5 - 2.0 g/liter for quick recovery during active vegetative growth stage.
• Foliar application of micronutrient mixture containing Zn, Mn, Fe, Cu, B at 30, 45 and 60 DAT for better crop stand (5 ml/liter).
• Well decomposed organic manures equivalent to 20 t FYM/ha may be applied 15 - 30 days before transplanting.
• During dry spell, thrips population may increase above economic threshold level (30 thrips/plant), in that case spray Profenophos 1ml/L or Carbosulfan 2ml/L or Fipronil @ 1.5ml/l for ef fective management.

Rain Deficit at reproductive stage  - Reproductive phase in onion does n ot occur during kharif season.

Terminal drought - One irrigation is sufficient at 85 days after transplanting. That may be provided by drip irrigation using harvested rain water.

Note: The above strategies can also be followed for late kharif and rabi crops in case of deficiency of irrigation water.

Source : NHM