Pomegranate with borer and blight: should the farmer force Hasta bahar?
A 1 ha Bhagwa pomegranate orchard planted in 2018 at 5 × 3 m near Jalore is under flood irrigation from a borewell. Water tests EC 3.4 dS/m and chloride 12 meq/L. In the third week of July, 14% of fruits show round holes with excreta near the calyx, and about a fifth of the canopy carries water-soaked angular spots that turn brown with a yellow halo; some fruits have black star-shaped lesions. Last season 30% of the fruit was unmarketable. A trader offers ₹85/kg for fruit harvested in October (Hasta bahar) against ₹40/kg for the normal February–March crop, but says quality must be good. To force Hasta bahar the farmer must stop irrigation in August, prune in September and induce flowering through a stress period; canal water is not available and labour is scarce. He has ₹40,000 for inputs over the next four months and asks whether to go for Hasta bahar on the whole orchard.
1. Diagnose the pest and the disease, and explain what role the irrigation water plays.
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The round hole with excreta near the calyx and 14% fruit damage is the pomegranate fruit borer (anar butterfly, Deudorix isocrates), whose larva enters around the calyx and feeds on seeds. The angular water-soaked spots turning brown with a yellow halo, and the black star-shaped fruit lesions, are bacterial blight (Xanthomonas pv. punicae, 'telya').
The water makes both worse. EC 3.4 dS/m with chloride 12 meq/L is above pomegranate's tolerance, causing marginal scorch, poor fruit size and a weakened tree. Flood irrigation also keeps the canopy humid, splashes bacteria onto leaves and fruit, and creates the free moisture and wounds that blight needs for entry. So this is a pest and a disease amplified by water quality and irrigation method, not two unrelated problems.
2. Advise on the Hasta bahar decision, using a budget and a risk argument.
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A partial go is defensible; a whole-orchard go is not. At 8 t/ha, October fruit at ₹85/kg returns ₹6.8 lakh against ₹40/kg × 12 t = ₹4.8 lakh for the normal crop, so the premium is real - but only for clean fruit. With 30% borer loss last season and active blight, 14% damage at harvest could destroy the premium. Forcing also means deliberately stressing the trees in August, and with EC 3.4 water and a stressed tree, cracking and small fruit are likely.
Recommendation: take Hasta bahar on the healthiest 0.4–0.5 ha only, after sanitation and two protective sprays, and keep the rest on Ambe bahar so the household has a normal crop and cash flow. Spend the ₹40,000 first on sanitation, copper sprays, fruit bags and drip for the forcing block, not on forcing the whole hectare.
3. Give an integrated four-month plan for borer, blight and water.
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Now: remove and bury every bored fruit and blighted twig; disinfect secateurs in sodium hypochlorite between trees; never prune in wet weather.
Blight: two sprays of copper oxychloride 0.3% with streptocycline (about 500 ppm) at 12–15 day intervals after pruning; keep foliage dry - that means drip, not flood.
Borer: 10 pheromone traps/ha and a light trap; bag fruits with muslin or paper bags at marble stage, which also reduces sunscald; spray Bt or spinosad at flowering and repeat after 15 days if trap catches rise, rotating groups and stopping 7–10 days before picking.
Water: shift to drip at 4–6 L/tree/day in two splits, mulch with 10 cm of residue, and leach salts once if any good-quality water is available. Restrict forcing to the healthiest block so the stress period does not coincide with a blight flush.