Fruit Drop its Causes and Measures to Control

Fruit drop is a premature shedding of fruits before harvesting for commercial purpose. There are so many reasons for fruit drop like internal (Hormonal balance, morphological and genetically) and external (biotic and abiotic) factors. Fruit drop is very much serious in some fruits like apple, peach, currant, mango, citrus etc. Fruit drop may occur at various stages of fruit growth, starting right from fruit setting till its harvesting. It may be natural, environmental or pest related. Losses due to fruit drop at various stages have long been a serious threat to the fruit growers. After determining the actual cause of fruit drop, adoption of a suitable control measure can bring relief to the growers. Among different drops, pre-harvest drop is of great economic importance which can cause serious crop loss to farmer.



References:
1. Fundamental of fruit production - K. Usha, Madhubala Thakre, Amit Kumar Goswami and Nayan Deepak, G
2. Fruit Drop Is Caused By - https://tipoftime.com/wp-content/uploads/uyqubb/fruit-drop-is-caused-by-ddb908

1. Fruit Drop its Causes and Measures to Control Md Mohsin Ali H210105018 DEPARTMENT OF AGRICULTURE RABINDRA MAITREE UNIVERSITY,KUSHTIA

2. Introduction Fruit drop is a premature shedding of fruits before harvesting for commercial purpose. There are so many reasons for fruit drop like internal (Hormonal balance, morphological and genetically) and external (biotic and abiotic) factors. Fruit drop is very much serious in some fruits like apple, peach, currant, mango, citrus etc.

3. Kinds of drop Post blossom fruit drop This is the first fruit drop begins right after the flower petals fall off and primarily consists of tiny fruits that may last two to three weeks. The dropping fruits are the ones that didn't get pollinated or the sperm cells from the pollen didn't make it to the ovary.

4. Kinds of drop June drop A second drop commonly occurs in apple, pear and less frequently, cherry in late May or June when the fruits are about marble size. This is the result of the plant's inability to support the vast number of fruits that it has produced due to profuse flowering and extensive pollination.In an effort to conserve energy, the plant drops the fruits.

5. Kinds of drop Pre harvest drop It is shedding of fully developed fruits just prior to harvest, more frequent in deciduous fruit crops. In apples as ripening starts, large amounts of the ripening hormone, ethylene is produced. It leads to fruit softening and the formation of an abscission zone in the stem.

6. Causes of fruit drop Premature fruit drop is related to unfavorable environmental conditions, for example, late frosts, excessive heat or cold and abrupt changes in humidity. 22 views. SOS was first detected in the United States in 2010 in Texas. The small dropping fruits are the ones that were not pollinated, so they will not develop further. They want to cross-pollinate with a different apple variety. Latest version. You may also like the Ecological Farming Benefits, Principles, Objectives. Moving citrus trees is the fastest way that citrus diseases are spread.

7. The role of inner agents in the drop of flowers and fruits: Non pollination Self pollination may fail due to various mechanisms, while cross pollination may be prevented in absence of pollinators, suitablepollenizers or due to adverse climatic conditions. Improperly pollinated fruits are more liable to fruit drop.

8. Over pollination The disadvantageous effect of supernumerary pollen grains on the stigmata, when more than 10–18 pollen gains are caught by the two lobes of the stigma, the latter faded severely just the next day and about 93% of stigmata died and dried out at the third day causing the drop of the respective female flowers. The role of inner agents in the drop of flowers and fruits:

9. Non fertilization Gametic sterility (b) Incompatibility (c) Failure of double fertilization (d) Abortion of embryo The role of inner agents in the drop of flowers and fruits:

10. Seed content of fruits Seeds, especially their endosperm are the sites of synthesis of growth substances like auxin which inhibits abscission of fruits. Auxin absorbs not only organic substances but also influences the distribution of cytokinins to the fruit, which is an active sink of metabolites.

11. Competition between the organs of plants (a) Competition between the vegetative and generative organs The relation between growth of shoots and fruit set is continuously changing during the growing season. If the source and consequently the transport i.e. photosynthates are restricted the fruits will drop. Balanced ratio of leaves and fruits leads for retention of fruits on the tree. At the time of the shed of petals, in apple 1–4 leaves are needed by one fruit set, around the June drop 10–15 leaves and at the end of fruit development 40 leaves provide the fruits.

12. (b) Competition between the generative organs In a tree having large mass of flowers or fruit primordia , the distribution of food is not optimum causing a vigorous drop of fruit. As a rule, a supernumerary bloom resulted in a low rate of fruit set. The flower or fruit set, which started growing earlier,becomes dominant in relation to other flower or fruits lagging relatively behind, this type of dominance is called primogenous . Competition between the organs of plants

13. The role of environmental agents in the drop of flowers and fruits Climatic and meteorological conditions Meteorological events before, during and following the development and vigour of flowers, bloom, fertilization and fruit setting are highly decisive and may influence fruit dropping.

14. Irrigation, water supply Competition for the restricted amounts of water is one of the causes of fruit drop. The prevention of fruit drop immediately by irrigation is also known. The role of environmental agents in the drop of flowers and fruits

15. Nutrition Proper and balanced application of fertilizers is a pre-requisite for a tree to be able to carry its normal crop to maturity. Nitrogen being essential for a normal fruit set and in avoiding the threats of June drops. The role of environmental agents in the drop of flowers and fruits

16. Biotic factors Pest and disease incidence on fruit plants can result in severe shedding of blossoms and fruits. The role of environmental agents in the drop of flowers and fruits

17. Pests The beetle ( Omophlusproteus ) attacks sweet cherry. They destroy the pistil or young fruit primordia . The fruit used to be drilled irregularly. The hurt flower or fruit primordia is fading and drop soon. The role of environmental agents in the drop of flowers and fruits

18. Fruit drop control in some important fruit crops Mango It exhibits maximum fruit drop among fruits i.e., 90-99% which occurs in the initial 3-4 weeks after fruit set. Main causes are lack of pollination, low stigmatic receptivity,defective perfect flowers,unfavourable climatic conditions like rain,wind and cloudiness at the time of pollination,incidence of diseases like powdery mildew,anthracnose,presence of hoppers, and mealy bugs,and hormonal imbalance in fruits.

19. Citrus In all commercial varieties of sweet orange, mandarin and grape fruit,fruit drop is a serious problem.The first drop occurring in the month of May and June is mainly due to inadequate and imbalanced manuring and insufficient care. Fruit drop control in some important fruit crops

20. (a) Prompt picking Prompt picking is an easy way to maximize the crop yield. As soon as true drop begins have the crop picked immediately. This strategy requires that growers should be aware of fruit dropping problem and regularly scout the plants for true drop . Management of fruit crops

21. ( b)Thinning To avoid fruit drop as a result of overbearing, thinning can be recommended for the young fruit before the tree drops it. In general, it is best to leave 4-6 inches between each fruit and break up any clusters that may form . Management of fruit crops

22. (c ) Water and moisture management Moisture stress during fruit set and fruit development causes severe fruit drop in most of the fruit crops. Too much water can also lead to fruit drop.Hence proper water management is required . Management of fruit crops

23. ( d) Temperature Mango trees do best in warm climates such as those found in subtropical and tropical locations, on the other hand they are very much prone to frost injury. Management of fruit crops

24. (e ) Nutrition management A balanced fertilizer programme should be adopted to control fruit drop.Before application of fertilizer, soil testing is necessary to confirm deficiency or toxicity of nutrients in soil . Management of fruit crops

25. (f ) Pest and disease management Suitable insect control strategy should be initiated to minimize their harmful effects. Be aware that using pesticide sprays while your trees are in bloom may terminate bees and other beneficial insects, and some sprays may even cause fruit drop . Management of fruit crops

26. (g ) Pollinizers These are the cultivars which provide abundant viable and compatible pollengrains to the main crop. Adequate number of pollinizing cultivar(s) should be planted at the time of planting . Management of fruit crops

27. (h ) Planting windbreaks and shelterbelts High wind velocity causes mechanical damage to the fruits and branches and also their desiccation due to excessive transpiration loss of water.Suitable windbreaks and shelterbelts are to be grown to provide a protective barrier against hot and cold wind and to reduce the extent of fruit drop. Management of fruit crops

28. ( i ) Use of growth regulators In different fruit crops, different growth regulators are recommended to control fruit drop . Recommended dose should be strictly followed, for e.g.2, 4-D at lower dose acts as a hormone, while at higher dose it acts as a herbicide. Management of fruit crops