Causes of fruit drop in mango tree
Hammad Hussain , Muhammad Iqbal

Mango (Mangifera indica L.) is a tropical and subtropical fruit that grows in many countries around the world.

Causes of fruit drop in mango treeWhen the mango tree begins to bloom and bloom in real time, you will see a large number of small mangoes on the stem, and then the plant will automatically adjust it. Fruit shedding is based on the availability of nutrients to balance crop loads, most of which decrease as nutrients increase. Don’t worry, this is natural. This natural decline involves a decline in physiologically mature or near-ripe fruits triggered by senescence signals.

In addition to this natural fruit decline, young, developing fruit primordia disappear before maturity, suggesting that senescence and shedding are independent phenomena caused by hormone imbalances. Ethylene stimulates cellulase synthesis and its effect on cell walls by up-regulating genes that express cellulase and pectinase. These genes will lyse interlayer cells and cell walls and form separate layers, eventually leading to the decline of flowers and fruits. Mango usually falls off the stem initially, not because of any insects or other problems.

A tree cannot support all the heavy fruits, only a certain percentage of the trees can mature into complete fruits. The fruit setting rate is low (0.1%), and the young fruit is greatly reduced (99.9%), causing huge losses to mango growers. Discarding some mango fruits is a normal tree thinning process, with the goal of properly utilizing the available nutrients. Immature fruits scramble to buy available food and water. Although the substantial reduction in mango fruit is due to many factors, such as lack of pollination, failure of fertilization, ovule and germ degeneration, and low sex ratios. The strongest will survive. Short-stemmed apple mango varieties, especially clustered mangoes, will be harvested “close” to each other. Early morning seedlings, especially reducing fruit clusters, will help prevent this decline. After picking fruits, they stimulate ethylene and cause more premature drops.

Pre-mature fruit drop of mangoes also due to anthracnose and powdery mildew. The symptoms of powdery mildew is white powdery substance show on fruits, foliage and twigs but in the case of anthracnose dark spots shows on leaves and sunken lesions also. Anthracnose disease affects all parts of the mango tree, but it has the greatest damage to spikes and is therefore the most dangerous disease resulting with almost no or less fruiting. Due to anthracnose, the infected mango fruit fell off the tree very early. Initially, it shows on the unaffected fruit rots rapidly as it matures, and the tree begins to lose its leaves.

Too much water can cause fruits to fall prematurely. Excessive or lack of fertilization may cause the fruit to fall. Excessive nitrogen can damage the flowers. Severe pruning of mango trees may reduce fruit yield. Therefore, in pruning only remove the stems and leaves of defective or diseased plants. If the frost is still present, do not trim dead branches. If the weather is cold during flowering and fruit setting, the fruit of the mango tree may fall. The cold damaged the developing embryos in the seeds, and the fruits fell off before maturation due to the ethylene gas released from the damaged embryos. It is dry or raining weather. Plant growth regulators are used to alter the growth behavior of plants. These are reported to play a major role in the growth and decline of mango fruits, which counteracts the enzymes that cause shedding area and fruit decline.

For anthracnose, copper fungicides can be sprayed and powdery mildew can be executed with sulfur fungicides. Mango anthracnose can be controlled with garlic, ginger or turmeric. Grind with some dishwashing liquid and add water. Discard or incinerate all infected parts of the plant. Try to keep the area around the plant free of weeds. Use complete fertilizers developed for fruit trees with the correct ratio of nitrogen (N), phosphorus (P) and potassium (K). Trees with higher P and K ratios. In orchards with incorrect soil nutrients, falls are usually more severe, especially with low magnesium (Mg), high potassium (K), and high boron (B) level.

The application of trace elements such as zinc, copper and boron has achieved better results in controlling fruit dripping and improving flowering and fruit quality. It is recommended to use 50 grams of zinc sulfate, 50 grams of copper sulfate and 20 grams of borax per tree / year. Choose a plant that reduces the chance of burning fertilizer and provides mango trees with the right amount of nitrogen and nutrients. Mix 6 tablespoons of fish emulsion per 1 gallon of water and spread on the soil around the mango tree. When CPPU (1,2-chloro-4-pyridyl -3-phenylurea) was injected at a concentration of 10 ppm on the 14th day, the mango tree was sprayed, with the result that the fruit retention rate per cluster and the effect on plant fruits.

The best results are affected by number, fruit weight, fruit volume and leaf area. Trim dead branches and leaves on the tree regularly to avoid any disease to the tree. Therefore, pruning can only remove the stems and leaves of defective or diseased plants. If the frost is still present, do not trim dead branches. The important role of leaf growth regulators (auxin, GA3 and 2,4-D) in fruit trees has been widely accepted, and the continuous supply of auxin from the docking organs is beneficial to maintain the shedding area. Lower auxin levels and exogenous application of auxins (such as NAA) can control the decline of mango fruit. Fruit setting rate (%) The initial fruit setting is directly related to the proportion of hermaphrodite flowers, but the final yield is not related to this ratio. GA 3 (15 ppm) leaves recorded the highest seed setting rate (84.84%) before flowering.

During this period, the application of GA 3 improved fruit set by acting on post-fertilization events, thereby inducing enzyme production. That is, peas, marble, and pre-harvest indicate that the average fruit reduction rate at each stage and all treatment stages was 70.93%, 10.19, and 7.84%, respectively. Applying gibberellin (35 ppm) on the leaves will result in a larger fruit size. Exogenous application of GA 3 will increase the cell size of the mesocarp (due to increased demand for water tanks, resulting in increased phloem degreasing capacity and increased carbon assimilation in fruit metabolism. Fruit weight (g). Mean weight  (g) concentration. The pulp weight recorded for 35 ppm gibberellin was significantly higher (95.3 g). Studies on changes in hormone concentration have shown that the levels of auxin (NAA) decrease with increasing fruit growth rate.

Auxins and inhibitors play an important role in the growth and decline of fruits. An increase in auxin levels corresponds to a period of rapid fruit growth, while high levels of inhibitors usually correspond to higher fruit decline rates from pollination to 42 days. Plant auxins appear to play a major role in fruit growth, while inhibitors appear to cause fruit decline. Foliar application of 15 ppm NAA produced 14% more perfect flowers (45.12%) than control plants (31.22%). Plants sprayed with 35 ppm NAA (78.15%) had the highest percentage of fixed flowers. NAA increases the perfect / germinated flower ratio of mango. Foliar spraying of 20-30 ppm NAA can improve the total soluble solids of “Langra” mango. The increase in TSS may be due to increased solute mobilization. 2. The TSS (19.5◦ sugar content) recorded at 4-D (35 ppm) was significantly higher, with the lowest percentage acidity (0.07%) recorded at 35 ppm in 2,4-D.

The increase in total sugar content in fruits is attributed to the degradation of polysaccharides to monosaccharides through metabolic activities, conversion of organic acids to sugars, and water loss. During rapid fruit growth, the content of inhibitors decreases and the content of promoters increases. However, during the slow ripening of fruits, the content of growth promoters and inhibitors is low. Therefore, all growth promoters play a role in the growth of the fruit. Deficiency of auxin, gibberellin and cytokinin, coupled with high levels of inhibitors, seem to cause the fruit of Mango Cash Dashehari to decline.