Peonies flower yield and post harvest handling
Peonies flowers can be harvested only after three years of planting. Commercial production starts with 5th year onwards and remains in production for more than 25 years. Remove all flower buds up to three years before taking commercial production. It helps to increase plant vigour and leaf canopy area. In the fifth year around 50 flowers are produced. Duration of flower harvest depends on climatic conditions. Hot weather shortens flowering season whereas cold weather increases their harvest period. Duration of flower harvest also depends on cultivars and their plucking stage.
Generally flower buds are harvested at the first sign of colour when the buds are medium firm to soft at 1.25-1.63 inch. Flowers of red cultivars open the slowest, pinks intermediate & white the fastest. Flowers should be plucked early in the morning & stored dry. They should be cooled at 1oc as soon as possible. Sorting & bunching of flowers is done quickly without letting them warm up. Keeping the foliage dry reduces the risk of Botrytis infection during storage and shipping.
Dealing with insects, pests and diseases
Peonies are free from major insect, pests’ problems. But sometimes insects like Thrips, flea beetles may be attacking the plant. They generally suck the sap from flowers and foliage and produces silver trails. Flea beetles attack during warm weather. It can be controlled by spray of Malathion (0.02%) or Endosulfan (0.02%) at regular intervals. Ants are frequently feeding on the sweet excretion of buds, but they are not harmful.
There are several diseases which often reduce the quantity and quality of flowers. The most commonly occurring diseases are botrytis blight (Botrytis paeoniae) and red spot, both fungal diseases. Botrytis causes stem, flower and bud rot during various stages of development. During attack new shoots turn black and die. Buds become brown. The infection spreads downward on the stem. Control measures include clean culture, removal of infected buds, pruning of old leaves at ground level and using of fungicides such as Bavistin (0.02%) or Bordeaux mixture helps to check the spread of disease. Other fungal diseases include Phytophthora blight, Sclerotinia stem rot and Verticillium wilt. These are soil borne fungi and should be controlled in the same way as with botrytis blight. In severe case destroy the infected plants and avoid replanting in diseased soil.
Several leaf spot diseases like Gloeosporium spp., Cladosporium paeoniae, Alternaria spp. and Septoria paeoniae also infect the plant. During infection brown spots develops on leaf which may kill the leaf. Application of mancozeb control leaf spots and other fungal diseases. Viruses may be a problem. Destroy any infected plants. Insects may transmit virus diseases. Keep fields weed free to control insects and viruses. Sometimes nematodes may be a problem. Avoid planting in nematode infected soil or apply Furadan before planting.