physiological disorders in grapes.pptx

Here is a detailed power point presentation on physiological disorders in grapes.

1. PHYSIOLOGICAL DISORDERS IN GRAPES AND THEIR REMEDIES BY: ROHITHA R

2. PINK BERRY FORMATION: Disorder is common in Thompson Seedless and its clone Tas-A-Ganesh [Maharashtra]. Pink blush develops on a few ripe berries close to harvesting. The pink colour turns into dull red and the berry becomes soft and watery. REMEDY: Spray 0.2% ascorbic acid and 0.25% sodium dimethyl dithiocarbamate at fortnightly intervals.

3. Pink berry formation:

4. SHOT BERRY: The berries become under developed and undesirable in the bunch. Perlette is prone to this disorder. This is due to the formation of number of bunches on the wine. REMEDY: Dipping the bunches at the berry stage in ethephon @ 25 ppm for 1 minute will control this disorder.

5. Shot berries:

6. Uneven ripening: Presence of green berries in ripen bunch of coloured grapes is called Uneven Ripening. It is a varietal character and problem in Bangalore Blue, Beauty Seedless and Gulabi Grapes. Generally inadequate leaf area and non-availability of reserves to a developing bunch is the reason. REMEDY: Application of Ethephon @250ppm at colour break stage is recommended to reduce this problem.

7. Uneven ripening:

8. Post- harvest berry drop: This is due to weak pedicel attachment to berries . This disorder is common in Anab-e-Shahi, Cheema Sahebi and Beauty Seedless. REMEDY: Spraying of NAA @ 50 ppm, a week prior to harvesting can minimize the post- harvest berry drop.

9. FLOWER- BUD AND FLOWER DROP: When panicles are fully expanded, the flower- buds drop before the fruit set. This is common in North India but not in South India. The reasons for this disorder is not known. REMEDY: Stem girdling about 10 days prior to full bloom can reduce this problem.

10. Flower-bud and flower drop:

11. Micronutrient deficiencies: MAGNESIUM: The typical leaf chlorosis is easily recognized at harvest time in heavy bearing vineyards, the leaves towards the ends of the canes being most affected. MANAGEMENT: Foliar sprays of MgSO4 @ 1kg/100 liters of water. ZINC: The lower portions of the newly planted vine just being trained up exhibit very small incupped leaves called little leaves. MANAGEMENT: Foliar spray of ZnSO4@ 500g/ 100 liters of water twice at 15 days interval before flowering.

12. BORON: Boron deficiency in grapevine commonly reduces fruit set. Further productions of more number of small and seedless fruits are seen surrounding the big berry. This phenomenon of bunches with varying sizes is called Hen and Chicken. Such fruits will be sour in taste and naturally weigh less than the fruits from normal vines. MANAGEMENT: The soil should contain 1 to 2 ppm of water-soluble boron. About 30 g of commercial borax per pit to rectify this deficiency. Foliar spraying of Borax @0.25% (2.5g/l it of water) is also recommended.

13. Magnesium: zinc: Boron: