land preparation

crop spacing (Source: jica.go.jp_

Plant pruning 

• It is a management practice where the number of running vines are restricted to two to three and also limiting the number of subsequent lateral branches. 
• It is aimed at reducing the number of bearing vines in order to maximize on the size and quality of fruits produced. 
• Farmer should aim at 4 to 6 fruits per plant to ensure large fruits often demanded by the market. 
• This can be achieved by restricting the number of fruits per lateral branch to 1 or 2 depending on the health of the plant.

Plant training

• It is a management practice where the two running vines and associated lateral branches are directed to grow in a direction away from the paths and irrigation channels.
• If under a trellis system, the two to three running vines and associated lateral branches are directed to grow along the trellises.

Water harvesting measure include; 

Rain water harvesting systems (ponds, dams and roof catchment).

Conservation agriculture include;

Mulching, Intercropping or drip irrigation system.

Drip irrigation

• The technology that supplements water in crop production systems. 
• It allows the optimal usage of the limited water resource by dripping water slowly into the crop roots at low pressure through a number of emission points (drippers). 
• Drip system saves water by minimizing evaporation losses and delivering water at the root zone where it is required. 
• It also provides the opportunity for farmers to increase crop yields. It’s easy to design and operated. The layout can either be above surface or buried below the surface.

Layout of a drip irrigation system in vegetables.

Rapid soil testing services

• This is a dry method for soil testing using simplicity of light—the interaction of electromagnetic radiation with matter to characterize biochemical composition of a soil and/or plant tissue.

• Handheld scanner and mobile app monitoring soil nutrients.
• It requires partners involvement (ICRAF, iSDA and AgroCares) to work closely with KALRO and County agricultural officers to sensitize farmers to embrace the testing method.

Types of weeds

Wondering jew sow thistle

Double thorn

Pigweed

Black jack Goat weed

Gallant soldier

Chickweed

Physical control include: 

• The removal of weeds manually or by mechanical means, such as hand weeding or mowing. In manual weeding farmers carry out manual weeding at 2-3weeks depending on environment, weeds present, rainfall or soils. 

Chemical control:

It is where appropriate recommended herbicides are applied to control weeds following the label. The weed composition needs to be identified and the data used to implement timely and the best management approach. 

Chemical Control:

Chemical weed control refers to any technique that involves the application of herbicide to weeds or soil to control the germination and growth of the weed species. 

Herbicide weed control is a technology that requires intensive knowledge on herbicides required for specific watermelon, when to apply and how application is done. 

Solarization Bed Control:

It is where you use transparent polythene and hot temperatures months to increase temperatures to kill weed seeds and seedlings. Basic phenomena is building up of lethally high temperatures in top soil where most dormant and viable seeds are present. 

Mechanism possible is breaking dormancy of weed seeds and solar scotching of emerged weeds and direct killing of weed seeds by heat. 

Stale seed bed Control:

Stale seed bed “false” is where seeds are allowed to germinate by rainfall or wetting and killing them (1-2flushes of the weeds) before sowing the Clean certified Watermelon variety seeds. 

They are killed using glyphosate, sulfosate and glufosinate. At this stage shallow or use of non-residue paraquat maybe used to destroy dense flush of young weed seedlings. 

Mechanical Control

There are several forms of mechanical weed control as described earlier ranging from handheld tools to the most advanced vision-guided hoes. Hand hoeing may be used to control weeds in small-scale farming as it is less safe to use herbicides in home gardening due to the lack of training.

Main harvesting stages:  

• Mature but before full ripeness for distant markets.
• Mature and ripe for nearby markets.

Fruits are ready for harvesting from 80 to 100 days from sowing. Harvesting continues for a further 40-50 days.  

Harvesting method

• Manual harvesting is the most common practice in Kenya. This is done by cutting the vine with a sharp knife, and NOT pulling, twisting or breaking off the vines. This avoids damage to the stem which causes stem end rot.
• About 2.5 cm length of stem should be left attached to the fruit when it is cut from the vine to deter against stem end rot.
• Water melons do not ripen after they are picked off the vine, so harvest time is important. If harvested immature, red colour will develop but sugar content does not increase after harvest
• Shading is necessary in order to protect harvested watermelon from direct sunlight which causes sunburn.
• Due to differences in pollination time, not all watermelons mature at the same time. Thus, the same field may be harvested more than once.
• Due to their large size and susceptibility to splitting or cracking under mechanical stress, watermelons should not be harvested in the early morning when they are most turgid.
• Using a damp cloth, manually rub off the soil attached to the ground spot 

Yields: 10-15 tons/ha.

Field assembling and packing 

• After harvesting, watermelons are stacked in the field, on the side rather than on their blossom end to reduce the risk of cracking. Placing them in a shaded area will minimize build-up of heat and avoid quality deterioration. The watermelons are packaged in fibreboard boxes or bulk loaded in bins in the field, taking care to load only dried rather than dew-covered fruits.
• Water melon are commonly shipped in bulk, placed on corrugated bins with a capacity of approximately 400 kg, or packed into cartons containing 3 to 6 watermelons depending on fruit size, and these cartons should have specially designed inserts to help support the weight of the fruit.
• Large sized watermelons are usually put in rows in the field prior to being picked up with a transport vehicle. Alternatively, a group of workers can go through the field and toss the melons from one worker to the next, eventually arriving to the person on the transport vehicle.
• Fruits of small sized cultivars (i.e. less than 5 kg) can be put in strong wooden field containers and carried out of the field. Usually 3 to 5 fruit are put in a field container. Field sacks should not be used for transporting the fruit out of the field, since they do not provide protection against bruising injury.
• Watermelons may be loaded directly from the field into the bed of a truck or trailer and transported to the market. This is essentially a form of field packing.
• Watermelons destined for export are taken in bulk from the field to a collection site for grading and packing. Workers should unload the fruit with care and place them on a packing table where other workers sort them into more precise size groups and pack them. Table surfaces should be covered with a non-abrasive material, such as carpet, to help avoid scratching the fruit.
• Watermelons packed for export should be put in strong double-walled corrugated cartons containing 3 to 5 watermelons, depending on fruit size and shape. The cartons typically weight between 25 to 35 kg. The carton should be stacked properly to permit adequate airflow through the load during transport.

Control of postharvest diseases 

• Fungal diseases are: black rot, anthracnose, phytophthora fruit rot, Fusarium and stem-end rot)
• Bacterial diseases are soft rot

Postharvest decay of harvested watermelon

Anthracnose decay of watermelon fruit (Source:Suslow, UC Davis)

Fusarium rot on ‘Sugar Baby’ watermelon

Greasy spot and associated whitish mold growth of Phytophthora infected fruit

Stem-end rot

Control

1. Careful sorting at harvest (discarding defective watermelon) and appropriate fruit grading before shipment
2. Holding fruits at 10oC will slow down the rate of disease development, compared to ambient temperature storage.
3. Spray with copper fungicides or systemic fungicides
4. Minimizing bruising of watermelon

Sorting and grading

Sorting 

• Watermelons are sorted to remove insect damaged, blossom-end rot, cracked, discolored, without stalk attached
• Inferior melons are sorted and packed in large, sturdy, tri-wall fiberboard containers.

Grading:

• Watermelon are graded based on their external appearances which include size (small, medium and large) for each variety. Good quality watermelon should be uniform in appearance and having a waxy bright surface devoid of scars, abrasions, sunburns, decays and other surface defects. Defecting fruits as a result of stacking or fruits dropping on the floor mistakenly can be sold at a cheaper price in nearby markets.
• Preliminary grading of market quality fruit should be done in the field at the time of harvest. Deformed, insect damaged, partially decayed, or cracked fruit should not be loaded or transported to the market.
• Watermelons destined for export must meet the quality standards established by the receiver. Typically, the fruits are more carefully inspected than those intended for the domestic market. The presence of diseases, insects, or soil can result in failure to meet phytosanitary requirements at the destination and lead to rejection of the entire shipment.
• In addition to the external appearance, randomly selected fruit should be cut open and checked for internal quality. The edible flesh should have a sugar content (minimum of 10% soluble solids), a deep red colour, and a pleasant crisp texture. These quality characteristics are dependent on fruit maturity, cultivar and postharvest care.

Fruits ready for the market after sorting and grading

Zero Energy Brick Cooler

The Zero Energy Brick Cooler consist of a double brick wall filled with sand in between, and a storage chamber. The sand is kept moist with water. The inside chamber is cooled through evaporation of the water in the sand.

Zero Energy Brick Cooler

Evaporative Charcoal Cooler

The Evaporative Charcoal Cooler consist of a double brick wall filled with charcoal in between, and a storage chamber. The charcoal is kept moist with water. The inside chamber is cooled through evaporation of the water in the charcoal.

Evaporative charcoal cooler for fruits and vegetables

Source: th.bing.com

Watermelon wine:  Wine prepared from ripe watermelon. It is made by fermenting watermelon juice by adding wine yeast and sugar.

source tasteofhome.com, 

Watermelon jam: Jam prepared from ripe watermelon

Source casaruraldavina.com

Watermelon powder: Powder prepared from drying watermelon juice

Watermelon flour: Flour prepared by grinding dried watermelon seeds

Source beyondtheequator.com

Watermelon seed oil  Edible oil extracted from dry watermelon seeds

http://www.essentialoil.in/

water melon candy 

sweets made from dried watermelon