Everything you need to learn about harvesting grapes organically. Learn about:- 1. Introduction to Grapes 2. Climate and Soil Required for Harvesting Grapes 3. Selection Site and Propagation 4. Training Systems 5. Planting and Spacing 6. Training and Pruning 7. Canopy Management 8. Alleyway Vegetation Management 9. Weed Control 10. Organic Nutrient Management 11. Quality Improvement and Few Others.
Contents:
- Introduction to Grapes
- Climate and Soil Required for Harvesting Grapes
- Selection Site and Propagation of Grapes
- Training Systems of Grape Vines
- Planting and Spacing of Grapes
- Training and Pruning of Grape Vines
- Canopy Management of Grapes
- Alleyway Vegetation Management of Cultivating Grapes
- Weed Control of Grape Vines
- Organic Nutrient Management of Grape Vines
- Quality Improvement in Grape Vines
- Rejuvenation of the Grape Vines
- Harvesting of Grape Vines
- Organic Management of Insect Pests and Diseases in Grapes
1. Introduction to Grapes:
The grape is one of the most favoured commercially grown fruit crop of the country. Grape (Vitis vinifera) is one of the table delicacies of India. It has fairly good source of calcium, phosphorus, iron and vitamins like B1 and B2. In India grape is grown in an area of 117.6 thousand hectares with a production of about 2,483 thousand tons (2012-2013).
Maharashtra has maximum cultivated area with 76.5% share followed by Karnataka with 16.72% of total area under grapes. As far as production is concerned, Maharashtra alone produces 82.55% of total grape production of the country, whereas, Karnataka produces 12.92%, Tamil Nadu 1.74% and Andhra Pradesh 1.26%. Northern states like Punjab, Haryana etc. have nominal area under grape production.
2. Climate and Soil Required for Harvesting Grapes:
Grape can be grown in north India (with limitations) comprising states of Punjab, Haryana and Western U.P but is mainly grown in states of Maharashtra and peninsular states like Karnataka, Tamil Nadu and Andhra Pradesh.
In northern states, grape vine sheds its leaves in winter and pruning is done in February- March months to give fruiting in months of June-July. Whereas in peninsular and western India because of absence of low temperatures grape vines do not shed leaves and two prunings namely foundation or back pruning in April and fruit pruning in October month are done.
In southern and western parts of the country temperature ranges from 15- 40°C and annual rainfall varies from 50-60 cm. For successful grape cultivation in southern and western parts timing of rainfall is more important. Rainfall should not coincide with fresh growth of shoots after fruit pruning in October and also during fruit ripening. Cloudy weather, high humidity, low temperature and precipitation during flowering and fruit development are detrimental as these conditions are highly favourable for disease spread.
Light and well drained soils are most suitable for grape cultivation. Even shallow soils can be used provided there is no hard substratum within top 1.5m. Clay loam soils can be used, if drainage is properly maintained. Ideal types of soils are sandy loams and silty loams, however sticky clay soils need to be avoided.
Soils with low pH < 6.5 and high pH 8.0 can be ameliorated by adding lime or dolomite in low pH soils depending upon pH level and type of soil. In case of high pH soils, gypsum can be added and quantity will depend upon exchangeable sodium present in the soil.
3. Selection Site and Propagation of Grapes:
Select soils having light to medium texture i.e. loamy and well drained. Do not select soils having pH more than 8.0 and chloride content more than 0.1%. Irrigation water should not have EC more than 0.75 m mhos/cm and chloride content should be less than 4.0 me/l. Depending upon the situation of soil site, one can raise grape vineyard on its own roots for normal soils or grape vines grafted on a suitable rootstock like Dogridge for difficult soils.
The most common method of propagation is by stem cuttings. Cuttings need to be taken from vines that have good vigour and yields. Cuttings should also be free of pests and diseases. Treat the cuttings of rootstocks with Pseudomonas fluorescens solution (10g/lit. of water) for 24-48 hrs. Similarly scion cuttings for raising plants on their own roots need to be treated.
Cuttings are usually planted in polybags having solar sterilized media i.e. 1 part sand: 1 part virgin soil- 2 parts of vermicompost. In case of rootstock, graft two shoots of rootstock with desired variety by using wedge grafting preferably in months of September- October. Grafted plants need to be protected against pests like thrips and diseases like downy and powdery mildew and also anthracnose.
Depending upon the problem, rootstocks can be selected. If nematodes are the main problem then rootstock 1613 needs to be used. For areas having problems of salinity and drought Dogridge is the best.
Preparation of Land and Lay Out:
Land is prepared by eliminating all types of shrubs and then ploughing and harrowing is done till fine tilth is obtained. It will be best to grow sunhemp (Crotalaria sp.) and plough the green manure crop at tender stage to upgrade the fertility of the soil.
Design the layout in such a way that rows are in north- south direction in case of “Y” or “T” trellises, but east-west direction is preferred in case of bower system of training. But in both cases the direction of arms should be north- south. In case of flat roof gable system also for vigorous varieties, allow secondaries in north-south direction.
If the soil depth is not adequate than trenching is done up to 2.5 feet depth and 2.5 feet width at 10 feet or 6.0 feet distance as per the planning. Then these trenches are filled with F.Y.M., farm waste, compost and vermicompost and are covered and irrigated at centre of the filled trench.
4. Training Systems of Grape Vines:
Training of grape vines is usually done on a single stem and ultimately vines are either trained as head system suitable for Beauty Seedless, Perlette, and Pusa Navrang and Pusa Urvashi varieties or on Kniffin, ‘T’ trellis,’ Y’ trellis or bower or flat roof gable system as described. Type of trellis depends upon variety, climatic conditions and extent of mechanization.
In grape several types of training systems, are being used; and these are bower, kniffin, telephone trellis, Y trellis and extended Y or flat roof gable system of training. In bower system of training, operations like thinning and dipping of bunches become difficult. Disease development is more likely in bower system of training because of favourable microclimate. “Y” and “T” trellises are suitable for humid areas and for higher degree of mechanization.
Extended “Y” or flat roof cable system of training has the benefits of both “Y” and bower. Training systems like ‘T’ trellis or ‘Y’ trellis or extended Y or flat roof gable systems are preferred in organic management as these systems provide open canopy with better air circulation and light penetration.
5. Planting and Spacing of Grapes:
Various planting distances were earlier adopted suiting to growth and vigour of different varieties. The distances of 4.5 m x 3.0 m or 3.0 m x 1.5 m were followed earlier. However, the latest trends under conventional management in spacing indicate that closer spacing is better for restricting vine growth and accommodating more plants per hectare. These days 2.0 m x 2.0 m planting distance and training them on bower is suitable for plants on their own roots.
Whereas, for grafted plants on rootstocks, planting distance of 2.0 m x 3.0 m and training them on bower or flat roof gable system is advocated. But under organic management such approaches may not be advisable as it may create favourable microclimate for disease development. In organic management wider spacing of either 2.0m x 3.5m or 2.5m x 3.5m, is suggested for vigorous varieties or for varieties grafted on rootstocks and trained on flat roof gable system.
Other varieties trained on T or Y trellis can be planted at a spacing of 2.0m x 3.0m. Extra space in between the rows can be used for growing cover or legume crops for higher moisture retention and for enriching the soil with biomass for higher biological activity. Intercrops will also help in promotion of beneficial insects.
Planting:
Pits of 30 cm x 30 cm x 30 cm size at a spacing of 2 m are opened. F.Y.M. /compost @ 5 kg per pit mixed with CPP/Amrit Pani/Jivamrit (20%) or 10 g each of Trichoderma viride, Pseudomonas flitorescens and Beauveria bassiana are added followed by light irrigation.
After 2-3 days, the rooted cuttings or the grafted plants on rootstocks are planted as the case may be. The best time for planting in western India has been found to be last week of February till the end of March. Newly planted vines need to be protected against attack of anthracnose, downy mildew, rust, Alternaria diseases and thrips.
Grape in India is mostly grown in semi-arid dry areas, which have inadequate rainfall and high evaporation losses, and under such situations supplemental irrigation becomes necessary. Water requirement of vines varies during different stages of growth. These days, drip irrigation is followed in majority of the vineyards to provide adequate water as per requirements.
Scheduling of water is based on pan evaporation reading, which is an index of water lost from the vines. The irrigation water quality must be good. Irrigation water should not have EC more than 0.75 m mhos/cm and chloride content of water should be less than 4.0 me/l. If the quality of water is not good then use salt tolerant rootstock like Dogridge.
Usually during shoot growth after April pruning, water requirement is high whereas during fruit bud differentiation and shoot maturity stages the water requirement is low. Similarly after October pruning, the water requirement is high during shoot growth whereas during bloom time water requirement is low.
6. Training and Pruning of Grape Vines:
Pruning in north India is done only once in January- February. Pruning is done twice where winters are not distinct i.e. first in April called foundation or back pruning and second in October which is called forward or fruit pruning. After foundation pruning, a series of developments like shoot growth, fruit bud differentiation, shoot maturity and fruit bud development take place.
Whereas after October pruning, after shoot growth, panicle emergence, flowering, berry development and ripening of berries takes place. It has been observed that for production of quality grapes, back pruning must be completed by end of April, whereas forward pruning must be done from 15th October to 30th October.
In forward or fruit pruning generally two types of pruning are done, (a) cane pruning and (b) spur pruning. Cane pruning involves cutting back 90% of the last years’ growth. First remove the dead two-year-old canes, and then select two well-formed canes growing out of the head of the vine.
The selected cane must be one-year-old wood, containing tightly spaced healthy buds. They should be at least of pencil width. Tie them to trellis wire and leave a replacement spur with only 2-3 buds to provide next year’s growth. Spur pruning involves looking at the new, one-year-old wood growing from the spurs of a cordon. Keep only 1-3 buds on each spur and prune back everything else.
Remember that the wood left behind is required to be trained to the trellis. Remove canes growing away from the trellis and also remove spurs that no longer have one year-old wood.
7. Canopy Management of Grapes:
The canopy management in a vineyard is most important orchard operation. Appropriate canopy management practices provide good air circulation and speedy drying which leads to reduction in humidity. In addition to this an open canopy structure of vines exposes the shoots, leaves, branches etc. to sunlight, which ultimately helps in reduction of diseases and improvement in yield and fruit quality.
Ideal Canopy:
The ideal canopy in a vineyard should fulfill following requirements:
1. The system should have convenience for easy mechanization and for carrying out day-to-day orchard management operations.
2. It should allow good ventilation and light into the vine canopy.
3. It should avoid overlapping of the foliage to facilitate efficient photosynthesis.
4. It should not allow buildup of microclimate congenial for development and spread of diseases and insect pests.
5. The system should promote and support heavy crop load of good quality fruits.
Out of all training systems for grapes like kniffin, ‘T’ trellis, ‘Y’ trellis and flat roof gable system, the flat roof gable system of training meets most of the requirements of an ideal canopy and is most suitable for vigorous or very vigorous varieties such as Thompson Seedless, Sonaka and Tas-e-Ganesh.
Flat roof gable system of training promotes vertical canopy, shoots arising from cordons after April pruning are generally erect during bud differentiation stage and harvest maximum sunlight which results in fruitfulness of canes. Also more tertiary canes in this system are positioned upwards, which are more fruitful than horizontal or downwards positioned canes (Fig 3). Less vigorous varieties like Sharad Seedless or wine varieties are more suited for Kniffin or ‘T’ trellis system of training.
Thus canopy management is adopted to obtain maximum yield and good quality fruits. These practices help in maintaining a balance between vegetative growth, extent of foliage and yield. Canopy management techniques allow opening up of dense canopies to develop strong shoots and increase cane maturity after April pruning. Practices like shoot thinning to retain productive shoots are also performed. Apart from this, canes which are very thin after October pruning, are also removed.
8. Alleyway Vegetation Management of Cultivating Grapes:
Alleyway vegetation management comprises of growing intercrops like legumes or cover crops or crops that can attract beneficial insects in between the two rows of grape vines. Growing legume intercrops helps in improving soil organic matter, controlling weeds, conserves soil moisture, providing appropriate habitat for multiplication of beneficial insects and in addition may also help in controlling insect pests and nematodes.
In existing vines, leguminous crops like green gram, black gram or cowpea can be grown during summer months, i.e. June – July onwards after April pruning. Their cultivation helps in enriching the soil and controlling weeds.
One cycle of cover crop and its subsequent mowing in soil adds 25-30 kg nitrogen/ha besides improving biological activity. During winter months cover crops like clover (Trifolium sp) and fenugreek (Trigonella sp) can be cultivated to enrich the soil and conserve moisture.
Alternatively in the centre of two vine rows grow 4-5 rows of mustard and two rows of marigold on both sides of mustard. These crops will also help in controlling weeds and provide ideal habitat for multiplication of beneficial insects.
Marigold as an intercrop also helps minimizing the population of root knot and reniform nematodes that affect grape vines. Taking care of nutritional and pest management requirements of such cover crops/intercrops is key to the success of harvesting their best benefits.
9. Weed Control of Grape Vines:
Cover cropping is the most effective method of weed control. One cycle of cover crop can minimize weed problem for almost four to 5 months. Subsequently mechanical methods can be employed. Mostly tractor driven implements are used for inter-cultivation and weed control in between the lines of vines trained on kniffin, telephone trellis or Y or flat roof gable system. Usually weed control before monsoon and after monsoon (in case if no cover crops are grown) is practiced through mechanical means.
Usually hydrogen cynamide is used for inducing bud break after October pruning. However under organic management, the same is accomplished by the use of 3-5% garlic extract spray. Crush 50 gm garlic cloves in 100 ml water using mortar and pestle, leave overnight in a refrigerator and filter through muslin cloth.
Add water to make 1000 ml. To make the solution more effective 50 ml of Vermiwash can also be added to this 1 lit solution. Treat the canes with this solution by smearing the cut ends or by spraying immediately after April and October pruning.
It is important to enhance fruitfulness in buds and best way is to treat the shoots during 30-70 days period after April pruning, as formation of fruitful buds takes place during this period. Usually chemicals like uracil and 6-benzyl adenine (6-BA) are sprayed on the shoots, foliage etc. for enhancing fruitfulness.
But since application of chemicals is not allowed in organic farming, therefore application of Vermiwash, cow urine and farm made protein hydrolysate is suggested, details of which are given in table below:
10. Organic Nutrient Management of Grape Vines:
Fully grown grape vines generally remove 210-220 kg N, 50 kg P, 260 kg K, 148 kg Ca and 48 kg Mg from one hectare area. While N, P and K are removed mainly through berries followed by wood and leaves, Ca and Mg are removed mainly through leaves. If entire pruning and fallen leaves are recycled 35-40% of NPK and 85-90% of Ca and Mg are returned back to the soil. While calculating the need for manuring this pattern should be kept in mind. Recommendations made under conventional management may also be taken into account for calculating the need for nutrients.
Under conventional management of grape vines in red sandy soils, a fertilizer dose of 300 kg of nitrogen, 500 kg of phosphorus and 750 to 1000 kg of potash per vine is recommended while in black clay soils 666 kg N, 888 kg P2O5 and 666 kg of potash per vine is advised.
Release pattern of nutrients from organic sources is also an important issue and needs to be considered. Usually 50% of N from organic sources is available in the first year and 25% in the second year, while remaining 25% is deposited in the stable humus complex.
In organic vineyards, the goal is to optimize resource use efficiency (land, water, nutrients) to maximize light interception and minimize internal canopy shading. Weak vines with undersized canopies will intercept insufficient available sunlight to ripen the fruit in the current season or to develop fruitful buds for the next season.
Conversely, over-stimulated vines with excessively large canopies have low water use efficiency and shade the fruit zone, leading to lower fruit yield and quality. Canopy size is strongly influenced by soil water and nutrient availability and the ability of the vine root system to take up water and nutrients.
Therefore, organic vineyards should strive to balance soil nutrient availability, organic matter content, cation exchange capacity, soil pH, and microbial activity, with vine canopy growth and vineyard goals.
Maintaining a soil a pH of 5.5 to 6.50 is essential to maximize the availability of potassium (K) and magnesium (Mg) with crop demand. pH below 5.5, increases the chances of aluminum toxicity, cation imbalance, and lower biological activity (lower N release).
A pH above 6.5 may result into excessive calcium and Mg which can inhibit K uptake and lead to K deficiency. Therefore usually a conservative range of ideal pH between 5.8 and 6.2 for vineyard soils is recommended.
The requirement of nutrients of grape vines is different at different stages of growth. It is well known that nitrogen requirement for shoot growth after pruning is quite high and nitrogen requirement during 30-60 days after April pruning when differentiation takes place bud is very low.
At fruit bud differentiation time, the phosphorus requirement, however, is quite high. Also during cane maturity, after April pruning as well as berry ripening time after October pruning, the potassium is required in high quantities.
Keeping all these situations in mind a schedule for organic nutrient management has been prepared. It is also realized that requirement of micronutrients like magnesium, zinc and iron will be met by addition of F.Y.M/compost/vermicompost etc. but in cases of acute deficiency established by soil tests micronutrients as per soil test recommendations can be used through the compost route (means micronutrient minerals are mixed with the compost during compost making process). In cases where alternate source of potassium is not available, then sulphate of potash can be used with prior approval of certification body.
Organic nutrient management is usually implemented through mixed application of nutrient rich manures as soil application, using liquid manures for growth promotion as soil drenching and feeding plants through foliar feed solutions.
For easy application concentrated manure mixture for soil application and liquid fertilizer for soil drenching and foliar feeding can be prepared as follows:
Preparing Organic Manure Mix:
For preparation of every 1000 kg of nutrient rich organic manure mixture, mix following organic nutrient materials in quantities mentioned against each:
Liquid Manures for Soil Application and Foliar Feeding:
Liquid manures for soil drenching and for foliar feeding through leaves is an important strategy in organic farming. Fermented cow urine, Vermiwash, Panchagavya and farm made protein hydrolysate are ideal inputs. For soil drenching CPP and Jivamrit can also be added to the solution.
For soil drenching mix 5 lit cow urine and 5 lit of farm made protein hydrolysate with 5 lit of Jivamrit in 85 lit of water. 200-250 lit of such liquid is needed for one acre area. For foliar feeding mix 5 lit Vermiwash or 3 lit Panchagavya and 5 lit of farm made protein hydrolysate in about 90 lit of water and use as foliar spray. 200 litre liquid is required for spraying the vines in one acre area.
11. Quality Improvement in Grape Vines:
Usually, grape bunches become compact at the time of maturity and there is no space for expansion of berries. For this GA (Gibberellic acid) is used especially for elongation of rachis, berry thinning and berry elongation. However, use of chemicals/ synthetic bio-regulators is not allowed in organic cultivation.
But gibberellins produced through fungal fermentation and extraction through allowed solvents and carriers can be used. Synthetic gibberellins being nature identical substances are also allowed for use in organic farming under certain circumstances, when natural source gibberellins are not available and its use is essential for the quality produce.
Care has to be taken that for berry thinning only selected bunches at full bloom stage are treated. Treatment with GA3 should not be done when weather is cloudy and likely to rain. For berry elongation do not dip clusters before they attain bajra grain size.
12. Rejuvenation of the Grape Vines:
Due to over cropping of young vines in the initial years, decline in yield of vines is observed. Also old vines, which were over-cropped and then neglected without subjecting them for appropriate pruning, will result in barren vines. To reactivate such vines, rejuvenation is practiced.
The ban-en vines are headed back to the ground level. Healthy and vigorous shoot is allowed to grow up to a height of adopted system of training and again trained for providing primary and secondary arms. There is a need to provide rejuvenated vines with required irrigation, nutrients and timely protection against pests and diseases. Normal crop from such vines can be taken in second or third year onwards.
13. Harvesting of Grape Vines:
It is very important to handle grapes very carefully during harvesting, transporting, cleaning, sorting and packing to avoid injury. Bunches should be harvested during the early morning hours and harvesting needs to be stopped as the temperature rises above 20°C. Otherwise it will be difficult to remove field heat later on from harvested bunches with in a stipulated time.
The harvested bunches are placed gently in clean perforated plastic crates of approx. 60 x 40 x 15 cm dimension and crates are left in the shade of the vines. Crates filled with grape bunches are shifted to pack house as soon as possible.
Post-Harvest Handling Practices for Long Distance Transport/Export:
Grapes after harvesting are immediately transferred to a pack house, where the temperature range of 15-20°C is maintained till packing. Operations like cleaning, sorting, grading and packaging are to be completed under clean hygienic conditions, within a period of 6 hours after which product needs to be shifted to cold storage for pre- cooling and storing.
Cleaning of bunches is done to remove immature, diseased, shriveled, undersized, off colour or under developed berries for improving the appearance of bunches as well as to prevent post- harvest decay. Bunches with sun scorching or damaged due to insect pests or diseases or water berries are removed before grading and packing.
Bunches are graded based on the size and colour of berries. Grading is usually done manually. While grading, bunches should be held by the peduncle. For export purposes the grapes must be firm, firmly attached and evenly spaced and with bloom virtually intact.
Packaging is normally done in corrugated fiberboard boxes. Usually a layer of bubble pad is placed at the bottom of the carton. To protect the grapes from bruising a polyethylene lining is placed over this. Bunches from weighed lots are placed in small, thin and clean food grade polyethylene pouches. Grapes are then pre-cooled to temperature of 4°C. This is then covered with polyethylene lining and the box is closed.
Commonly 2 kg box or 5 kg box is used. After this the boxes are pellitized and stored till loaded in the container. The storage temperature at 0 to +0.5°C and 95% RH is the best for freshness of berries.
Grapes meant for raisin making should preferably be seedless, white, with thin skin and T.S.S between 20-24°. Select fully ripe bunches and remove diseased and damaged berries. Initially, sulphuring a treatment of sulphur fumigation of bunches was the common practice, but recently it has been replaced by dipping berries in Australian dip emulsion. Berries are dipped in a solution containing 2.5 kg of potassium carbonate and 1.5 lit of ethyl oleate (fatty acid) in 100 litres of water for a period of 3 minutes.
After this, berries are dried in fabricated drying sheds based on covered iron rack system for a period of 10-12 days. Under organic production system dipping in oil solution may be added with the approval Certification Body.
Packing of raisins is done in 400 gauze LDPE film bags and stored in CF boxes of 5-15 kg capacity at low temperature of 4°C.
14. Organic Management of Insect Pests and Diseases in Grapes:
Organic pest management in grapes is an integrated approach combining cultural, mechanical and biological approaches with major emphasis on problem avoidance, pest repellence, and biological strengthening of control agents and keeping the soil healthy with adequate manuring. Healthy soils, use of resistant varieties, using disease free saplings and raising them in disease free environment are some of the important preventive strategies.
Sterilization of potting medium followed by drenching of medium with T. viride and P. fluorescens and drenching treatment of nursery with Trichoderma viride and Pseudomonas fluorescens, prevents all soil borne diseases in grafted plants. Maintenance of proper spacing, mulching and manuring at scheduled intervals also helps in effective management of pests and diseases.
Some of the important ecological and cultural strategies found effective in containing the pest problem below economical threshold level (ETL) are as follow:
1. Frequent growing of legume cover crops and mulching of their biomass along with some other crop residue and weed residue.
2. Adequate use of organic manures followed by biomass mulching and drenching of biomass with fermented dung-urine slurry (such as Jivamrit) ensures high activity of beneficial microbes that act as deterrent to harmful microorganisms and insects.
3. Plant marigold plants on sides and in between the two rows of vines for managing nematodes.
4. Ensure natural habitat and survival conditions for natural pest enemies such as pest predators, parasites and pathogens.
5. The vineyard must have permanent diversity plantation comprising nitrogen fixing plants like Gliricidia, Leucaena lecucephala etc. fruit plants like custud apple, ber etc. on borders and pesticidal value plants such as Adathoda Ipomea, Vitex (nirgundi) etc. planted randomly in between border plants.
6. Raise the flowering plants/compatible cash crops along the vineyard border by arranging shorter plants towards main crop and taller plants towards the border to attract natural enemies as well as to avoid immigrating pest population. Grow flowering plants on the internal bunds inside the vineyard. Do not uproot weed plants those are growing naturally like Tridaxprocumbens, Ageratum sp, Alternanthera sp, which act as nectar source for natural enemies.
7. Release and protect beneficial insects such as pest predators and parasitoids comprising ladybird beetle, hover fly, green lacewing, spiders, predatory mites, Bracon hebetor, Trichogramma, long horned grasshoppers, Chrysoperla, earwigs, etc.
8. Pheromone traps for Spodoptera @ 4-5 traps/acre should be installed for surveillance and mass trapping. Install the traps for each species separated by a distance of >75 feet in the vicinity of selected field. Fix the traps to the supporting pole at a height of one foot above the plant canopy. Change of lures should be done at 2-3 week interval (regular interval). During each week of surveillance, the number of moths/trap should be counted and recorded. The trapped moths should be removed and destroyed after each recording.
9. Blue Sticky Traps – Set up blue sticky traps 15 cm above the canopy for monitoring thrips @ 4-20 traps (15 X 7.5 cm)/acre. Count the number of pests on the traps daily and take up the intervention when the population exceeds 100 per trap.
10. Light traps – Set up light traps @1 trap/acre 1 feet above the crop canopy for monitoring and mass trapping insects. Light traps with exit option for natural enemies of smaller size should be installed and operate around the dusk time (6 pm to 10 pm). Count the number of thrips on the traps daily and take the appropriate decision regarding management practices.
11. Apply mycorrhiza and plant growth promoting rhizobacteria (PGPR).
12. Apply Trichoderma viride/harzianum and Pseudomonas fluorescens as sapling and pit soil treatment.
13. In case if there is problem of nematodes then also apply Paecilomyces lilacinus as soil treatment.
Diversity plantation for insect attraction and as trap crops is an important strategy. Important insect attractant plants for grape insect pests are: carrot, sunflower, Desmodium, buck wheat, French bean, alfalfa, mustard, cosmos, anise, caraway, dill, Chrysanthemum, maize and urad bean. Important repellant plants are Ocimum sp, peppermint/spearmint. Trap plants are marigold and castor. All these plants can be planted on border, on internal bunds as well as intercrops also.
Keep on watching the pests to defender ratio, which is generally maintained at 2:1.