Get the answer of: How to Harvest Sunflower ?
Sunflower crop matures in 90-100 days. The crop has to be harvested when the lower side of the head turns yellow, some of the bracts dry up and bottom leaves start drying and withering. Mature heads are cut with a sickle and dried in sun for 2-3 days.
Well dried heads are beaten with sticks to separate the seed. Power operated threshers are available for large seal threshing. The seed is cleaned by winnowing. Cleaned seed is dried for a day or two to bring the seed moisture content to less than 10 per cent for safe storage.
Post harvest losses occur at different stages viz. harvesting, threshing, winnowing, transportation, packaging, storage and processing.
To avoid post-harvest losses, following preventive measures should be considered:
1. Harvest timely to reduce losses.
2. Adopt proper method of harvesting.
3. Adopt modern mechanical methods to avoid the losses in threshing and winnowing.
4. Use improved techniques of processing.
5. Adopt the grading to get better price.
6. Use good packaging materials for storage and transportation.
7. Use proper techniques in storage.
8. Moisture content of the seed should be less than 9.5 percent for storage.
9. Adopt proper pest control measures during storage.
10. Adopt timely and proper handling while loading and unloading.
11. Avoid use of hooks during handling.
Harvesting care:
Losses in the field occur at the time of harvesting due to untimely harvest, poor agricultural operations, careless handling, birds, rodents, bad weather conditions like heavy rainfall, hailstorm etc. During harvesting, proper care should be taken to avoid quantitative and qualitative losses.
Following care should be taken during harvesting:
1. Sunflower should be harvested when the plant attains physiological maturity i.e. when the back of the head turns from green to lemon yellow colour and the bottom leaves starts drying and withering.
2. At physiological maturity, seed attains maximum weight and oil concentration and harvesting at this stage, results in highest seed and oil yield.
3. Ten per cent of heads should turn brown and florets attached to the tip of the seeds drop off naturally.
4. Delay in harvesting causes reduction in seed yield due to lodging of plants and more damage due to birds, rodents and termite attack.
5. Harvesting should be done by adopting proper method.
6. Chemical defoliation or desiccation using diquat, magnesium chlorate or dipyridyl phosphate should be used to accelerate drying of standing crops.
7. Mechanical thresher should be used to separate seed from flower which is labour saving and economical.
8. Avoid harvesting during adverse weather conditions i.e. rains and overcast weather.
Bird damage management:
Bird damage is a serious problem in sunflower cultivation. Sunflower crop is damaged by birds during the period from seed filling to harvesting. The rose- rigned para keets (Pesittacula krameri) are major bird pests of sunflower causing 10-40 per cent damage and in isolated area it may cause damage more than 90 per cent. Parrots invade the crop in flocks and inflict heavy damage and known to waste much more than what they eat.
Sunflower cultivation should be done in large continuous blocks as parrots create serious problems in isolated areas. Bird scaring like tying of bright reflector ribbons above the crop should be used particularly in the morning and evening hours.