MANAGEMENT OF INSECTS AND DISEASES IN GREENHOUSE

 

 

 

 

 

 

 

 

 

 

 

INSECT PESTS

TARGET	PRODUCT (AI)	Brand name	RATE/15lts	FREQUENCY	PHI	IMAGE
Aphids	Acetamiprid + Lambdacyhalothrin or Novaluron + Bifenthrin	Prodal Rimon Fast	30mls 25mls	Once identified	14 7
Cut worms	Acetamiprid + Lambdacyhalothrin or Novaluron + Bifenthrin	Prodal   Rimon Fast	30mls   25mls	Drench once the case is noted	14   7
Leaf miners	Acetamiprid + Lambdacyhalothrin or Novaluron + Bifenthrin Emmamectin Benzoate	Prodal Rimon Fast Protect	30mls 25mls 10mls	On seeing a mark  on leave	7 7 7
Bollworms	Acetamiprid+ Lambdacyhalothrin or Novaluron + Bifenthrin	Prodal   Rimon Fast	30mls   25mls	Start early if the case is noted	14   7
Thrips	Emmamectin Benzoate or Acetamiprid + Lambdacyhalothrin	Protect Prodal	10mls 30mls	2nd week after transplanting, Onset of flowering then after scouting	7 14
White flies	Acetamiprid + lambdacyhalothrin or Novaluron + Bifenthrin	Prodal   Rimon Fast	30mls   25mls	Once identified	14   7
Mites	Abamectin+ Acetamiprid or Novaluron + Bifenthrin	Diuthryn Rimon Fast	20mls 20mls	Once identified	7 7

TOMATO DISEASES AND THEIR MANAGEMENT

Late Blight (Phytophthora infestans): On tomato leaves, light brown to purplish spots that rapidly enlarge to purplish, blighted areas. Early in the morning and under wet conditions, a white growth of the fungus may be visible on the lower leaf surface. The spots eventually turn dry and papery. Stems may become infected, as well, with large purple to black sections that make stems look as if they were burned.

On infected tomato fruit, mahogany to purple blotches appear, sometimes in a ring pattern and fruits often become overcome by a foul-smelling soft rot, as secondary bacteria follow the late blight infection. To control late blight, begin with disease-free transplants. Next, space plants far enough apart in the greenhouse or open field so that plants will dry off quickly during the day i.e. after sprays or rainfall. Prophylactic sprays with preventative chemicals like Funguran® at rate of 50gms per knapsack is necessary especially during cool weather. Crop should be inspected frequently and if the symptoms are noticed a curative chemical should be sprayed, Metalaxyl + mancozeb at rate of 50gms per knapsack. If late blight is a yearly problem in your farm, you may have to resort to crop rotation with crops of different family.

Early Blight (Alternaria solani): On leaves, symptoms begin as small, pencil-point-size, dark brown to black spots. The spots enlarge up to a half inch in diameter and usually have readily visible, concentric rings that look somewhat like a bull’s-eye. Similar concentric rings are seen in lesions that develop on stems and fruit. When the fungus attacks young stems, complete girdling of the stems may occur with subsequent plant death. Fruit lesions are usually at the junction of the fruit and fruit stem or on the portions of the fruit nearer the stem and are conspicuously sunken. To control early blight, start with disease-free transplants and fertilize plants adequately. Inadequate nitrogen levels, in particular, make tomatoes more susceptible to early blight. A prophylactic spray with preventative and curative fungicides is necessary especially in cool wet weather. Prophylactic sprays with preventative chemicals like Copper is necessary especially during cool weather. Crop should be inspected frequently and if the symptoms are noticed a curative chemical should be sprayed, Mancozeb

Fusarium Wilt (Fusarium oxysporum f. sp. Lycopersici): Infected transplants are stunted, the older leaves droop and curve downward, and the plants frequently wilt and die. Symptoms on older plants generally become apparent during the interval from blossoming to fruit maturation. Earliest symptom is the bright yellowing of older, lower leaves, often on only one side of the plant, and the leaflets on one side of the petiole frequently turn yellow before those on the other side. The yellowing process gradually includes more and more of the foliage and is accompanied by wilting of the plant during the hottest part of the day. The wilting becomes more extensive from day to day until the plant collapses. The vascular tissue of a diseased plant is dark brown. Browning often extends far up the stem and is especially noticeable in a petiole scar. This browning of the vascular tissue is characteristic of the disease and can be used for its tentative identification. Fruit infection occasionally occurs and can be detected by the vascular tissue discoloration within the fruit.

Control of Fusarium wilt for small scale farmers is primarily by use of tomato varieties with resistance to the disease. In green house farming it’s important to do soil and water analysis before planting so that to determine the presence or absence of this fungus. If the farm is infected it’s advisable to do soil fumigation with Metham sodium® before planting. Continuous drench of Carbendazim controls the disease.

Bacterial wilt (Ralstonia solanacearum):The initial symptom in mature plants under natural conditions is wilting of upper leaves during the hottest part of the day followed by recovery during the evening and early hours of the morning. The wilted leaves maintain their green color and do not fall off as disease progresses. Under conditions favorable to the disease complete wilt occurs. The vascular tissues in the lower stem of wilted plants show a dark brown discoloration similar to those of some fungal diseases. A cross section of the stem of a plant with bacterial wilt produces a white, milky ooze of bacterial cells in clear water.

Cultural practices, if judiciously used, may reduce disease incidence. Seedlings must be free from infection by R. solanacearum.  Use treated or pathogen-free irrigation water with Calcium hypochlorite. Fields should not be over-irrigated because excess soil moisture favors disease development. Crop rotation and cover crops with non-susceptible plants reduce soil borne populations of the bacterium. Use of grafted tomato with a resistant root stock is a promising method of control or heating of the planting media

Anthracnose: Symptoms include, small, round; sunken spots appear on the fruit. The spots will increase in size and darken in the center. Several spots may merge as they enlarge causing fruit rot. The fungus is often splashed onto the fruit from the soil. It can also take hold on Early Blight spots or dying leaves. Wet weather encourages the development of Anthracnose. Overripe tomatoes that come in contact with wet soil are especially susceptible. Management: Copper sprays offer some resistance. Remove the lower 12″ of leaves, to avoid contact with the soil. Don’t water the leaves, just the base of the plant.

Powdery mildew: Symptoms of the disease occur only on the leaves. Symptoms initially appear as light green to yellow blotches or spots that range from ¹/₈ – ½ inches in diameter the spots eventually turn brown as the leaf tissue dies. The entire leaf eventually turns brown and shrivels, but remains attached to the stem. A white, powdery growth of the fungal mycelium is found on the top of leaves .These powdery mildew fungi are obligate parasites; they can only survive on a living host. The fungus produces specialized feeding structures called Haustoria that invade host cells to extract nutrients. The removal of nutrients from host cells causes the yellowing and eventual necrosis of tomato tissue. The plant is not killed by this disease, but is progressively weakened and productivity greatly decreased. Control the disease by frequent sprays with carbentazim.at 50gms per knapsack.

 Tomato Spotted Wilt Virus: A wide range of symptoms can occur with TSWV. Small, light brown flecks first appear on leaves. These spots later turn brown, followed by a general browning of leaves that die and appear drooped on stems. Brown to purple brown streaks form on stems. Plants are often stunted and, with the droopy leaves, appear wilted. Green fruit show concentric rings of yellow or brown alternating with the background green color. Striking brown rings occur on red-ripe fruit. Vigilant weed control may reduce the incidence of TSWV, Control of thrips helps to reduce late infections. Varieties resistance to TSWV should be encouraged.

Tomato Yellow Leaf Curl Virus (TYLCV): This virus is transmitted by a species of whitefly. Leaf edges curl upward and appear mottled and the tops of plants appear bushy. Often, fruit set is poor or nonexistent.Control of TYLCV is difficult. Varieties with resistance to TYLCV should be used if available. Susceptible varieties can be grown, but successful control of this virus begins with the purchase of TYLCV-free seeds or transplants. An isolated, infected tomato plant can be removed and destroyed in an effort to eliminate sources of virus that might infect other tomatoes. A lengthy period of time between plantings in the greenhouse will help break the cycle that can lead to repeated virus infection. The control of whiteflies is essential to prevent the virus from spreading from diseased to healthy tomato plant

DISEASES

TARGET	AI(Active Ingredient)	Brand name	RATE/15lts	FREQUENCY	PHI	IMAGE
Late blight Early blight	Copper hydroxide  Metalaxyl + Mancozeb	Kocide Metazeb	50gms 50gms	Ones after 2 weeks On noting the case	3	Early               Late
Powdery mildew	Metalaxyl + Mancozeb	Metazeb	50gms	Fortnightly on humid weather
Bacterial specs	Copper hydroxide	Kocide	50gms	Onset of rainfall on weekly basis	3
Fusarium wilt	Metalaxyl + Mancozeb Copper hydroxide	Metazeb Kocide	50gms 50gms	3 weeks interval Start 2nd week after transplanting	14 3
Mosaic virus	Control all insects		____	Uproot all affected plants	____
Septoria leaf spot	Metalaxyl + Mancozeb Copper hydroxide	Metazeb Kocide	50gms 50gms	Ones after every 3 weeks especially on humid weather	14 3
Anthracnose	Metalaxyl + Mancozeb	Metazeb	50gms	Onset of fruiting, When case occurs	14
Bacterial wilt	Copper hydroxide (Retards rate of bacterial cell multiplication)	Kocide	50gms	Weekly basis if infected, especially as from fruiting stage	3

FIELD ACTIVITIES

Training/Staking and Trellising

Training/Staking will help plant to grow vertically while Trellising support the plant to grow horizontally. This provides good aeration under the laid stems, easy fertilizer application and weeding and avoids the fruits from touching the ground.

The bags (if pot farming) and lower trellising lines are used as base of laying the stems of the trellised plants. Two weeks after transplanting, support the plants with a twine attached to the horizontal top and down running wires. The plant should be manually directed as it grows upward. Avoid yellow colored plastic lines for they attract insect pests.

Training/Staking will help plant to grow vertically while Trellising support the plant to grow horizontally. This provides good aeration under the laid stems, easy fertilizer application and weeding and avoids the fruits from touching the ground.

Once the stems reach the wires above, they should be untied and lowered as far as they can go without the fruit touching the ground. Plants should be moved clockwise and then tied to the wires above. This should be done regularly at least every two weeks. For plants close to the end of the rows, wrap around onto the row on the other side of the bed. Trellising should be done at the mid of the day to avoid stem and branch breakage.

De-suckering

Excessive foliage leads to overcrowding effect that reduces air circulation within the crop, overshadowing of the lower parts of the crop inhibiting photosynthesis, encourages building up of fungus infection and flower abortion.

Always maintain a single stem by removing any upcoming lateral shoots (should be done timely before they overgrow).Sterilize the pruning tool within the de-suckering process to avoid transmission of diseases from one plant to another if using any.

 

 

De-suckering

 

 

Pollination

By light shaking of the plant tapping the upper trellising lines- between 12pm to 3pm.Simply tap the trellis or training line with a stick. This is enough impact to let pollen dust into the stigma of the flower.This is because insects that freely pollinate the flowers are not necessarily finding their way into the plants inside the greenhouse.

In hot and humid areas, use fruit setting solution at the rate of 2mls/1lt. of water twice per week.

 

Defoliation

Remove all leaves below mature ripening fruits. Old leaves require to be removed since they hide insect pests and diseases’ pathogens. All defoliated leaves should be removed from the fields because they can attract and or keep diseases e.g. powdery mildew or become breeding grounds for crop enemies.

 

 

 

*Over defoliation*-not allowed

 

Harvesting

Harvesting should be timely (when fruit color changes to pink). Avoid leaving the fruits to over ripe while on the plant. All the fruit cluster attachment, after harvesting should also be removed. Fruit harvested at this time is red internally and will turn red. Such fruit, however, must be packaged and moved to the market immediately for it to be a proper color when placed on the grocery shelf. Mature green tomatoes can be harvested and treated with ethylene (ripening gas) under appropriate conditions to develop color. Green fruit are usually harvested less frequently than ripe fruit.

Sorting and Packing

Tomato fruit should be sorted by size and color to have a uniform pack suitable for various markets. Only one size and color should be placed in a box. This allows buyers to know what they are purchasing and improves a grower’s reputation for packing a high quality product.

 

CLEANING AND SANITATION

The greenhouse should be kept clean by removing out the rotten fruits, weeds, dead plants and leaves.

Foot bath and hand wash should be provided. Disinfection of the pruning tools should be done using Sodium Hypochlorite (Bleach) solution or any other disinfectant.

CROP ROTATION

It’s a very important activity in any crop farming regime that needs to be always observed.

Crops used for rotation should not be from the same family, for this helps to break the breeding cycle for stubborn crop pests.               

RECORD KEEPING

Record keeping is a very important part of any business for several reasons;

• Traceability– is the ability to trace the history or location of an article or activity by means of recorded identifiers.
• Health safety of the operators, consumers and visitors. Guided by the chemicals applied and observance of the Pre Harvest Intervals to Harvest.
• Guide to the type and amount of water, manure, fertilizers, pesticides and any other chemicals actually applied

• Observance of each stage of crop cultivation.

• Objective measures of actual plant and crop yields on a consistent basis

• Learning – with any activity the accumulation of accurate timely records can improve the learning and expertise of both AFK owners and operators.

• Provides a good database for Dizengoff Support Staff during their interim supporting visits to your AFK.

• Security over the records of your harvested crops

• Evaluation of profitability of the AFK enterprise based on the records of all actual input costs versus the record of actual output revenues from the sales of harvested crop

SUMMARY

FUNGICIDES			Carbendazim,Copper Hydroxide	Mancozeb+Metalaxyl Carbendazim,	Carbendazim, Mancozeb+Metalaxyl Copper Hydroxide
INSECTICIDES			Emmamectin Benzoat	Abamectin, Emmamectin Benzoat	Abamectin, Emmamectin Benzoat
NUTRIENTS		Bonus 20:20:20	smart fertilizer	Tecnokel Hafa cal/cal.nitrate	Tecnokel Haifa cal/Cal.Nitrate
VARIETIES Eva Nemonetta Claudia	Land/media preparation	Nursery	Transplanting	Vegetative development	Fruit development & Ripening
	Days/weeks	0-btn 21st&28th	28th day onwards	30 days after transplanting	140th day
	Multi K/NPK per 1000lts		500gms	1KG	1KG

 

  SF/NPK                                                                                                 Haifa cal/Calcium nitrate                                                                                   Haifa cal /Cal.Nitrate       

30g/plant                                 5-10g/Plant                                            5g/plant

ACTIVITY	OPERATION	PROCEDURE
Land/planting media preparation	Digging Or Pot media treatment	Double dig the land to a depth of 60cm and have a fine tilth Apply well decomposed manure and mix thoroughly with the soil Top soil mixing with well decomposed manure, heating, cooling and potting
	Bed shaping/Potting bags arrangement	Shape the bed as recommended,80 – 90cm wide Arrange the planting bags on plastic mulch, each to have double drippers
	Setting trellis line	Should be parallel with the drip line, on the outer side, leaving a space after the drip where the seedling will be planted
Nursery	Planting	1.        Plant one seed per hole in the tray with nursery media 2.        Feed with Poly-feed at the rate of 10g/knapsack in 3-1-3-1 pattern.
Transplanting	Spacing	1.        Transplant at 60cm X 60 cm or 1 seedling per growing bag
	Fertilizer application	1.        Apply Smart Fertilizer (SF) at the rate of 50g (5 table spoon ) per hole/bag or NPK 15:15:15 30gms. 2.        Mix with moist soil. 3.        Transplant. 4.        Irrigate
Vegetative Development	Top dressing	1.        Apply Haifa cal./Cal.Nitrate as ring band around the plant 30 days after transplanting. (5- 10g/plant) 2.        Has to be covered with the soil after application 3.        Irrigate if not well moist.
	Pruning	1.        Remove all side branches and maintain only main stem.
	Training/Staking	1.        Tie the thread on upper and lower wire supporting the plant.
	Fertigation	1.        Start feeding with NPK in the fertigation tank at the rate of 0.5g/1lt. 2.        Eventually move to 1g/1lt. after a month
	Pest & Disease control	1.        For pests follow the guidelines provided to control them once identified. 2.        For diseases institute protective measures and curative measures once identified. Use the guidelines provided for identification.
Fruit Development & ripening	Pruning,  Trellising pest & Diseases	Continue as above On trellising, lower the defoliated and harvested stem part on horizontal position
	Fertigation	Multi K/NPK   1g/1lt. of  fertigation water