Lettuce Crop Trial

7/30/2019 Lettuce Crop Trial

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RoyWattsRd

Lettuce crop trial

Introduction: The lettuce variety grown is green coral lettuce. The lettuce was grown on raised beds

for better drainage with three rows of lettuce on each bed. The recommended spacing for the

lettuce was 20cm between each lettuce.

Aim: The aim is to determine whether the recommended spacing of 20cm x 20cm will produce a

heavier crop of lettuce on average compared with 18cm x 18cm and 22cm x 22cm.

Hypothesis: The recommended spacing of 20cm x 20cm will produce the heaviest lettuce on average

compared to the other treatments.

Layout:

X

Lettuce crop method:

1. Cultivate the soil2. Mushroom compost is spread onto of the soil3. Gypsum is applied to the soil4. Raised beds of equal size are formed5. Lime is applied to the beds6. Lettuce seedlings are planted on to the beds in 7 x 3 formation and its treatment7. Fertilizer is applied as the plants are watered8. Lettuce is watered every day and mechanically weeded9. Pest management practices are used; nasturtium plants around the beds, snail/slug pellets are

spread around the plants, pyrethrum insect spray applied to the lettuce

10.Harvest 8 weeks after planting or before lettuce begins to bolt. Note time varies according tohow long ago some pesticides were applied to the lettuce plants

Bed 1

Spacing: 18cm x 18cm

Lettuce: 7 x 3

Bed 2


Lettuce: 7 x 3

Bed 3


Lettuce: 7 x 3

Bed 4


Lettuce: 7 x 3

Bed 5


Lettuce: 7 x 3

Bed 6


Lettuce: 7 x 3

Bed 7Spacing: 22cm x 22cm

Lettuce: 7 x 3


Lettuce: 7 x 3


Lettuce: 7 x 3


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significant enough to be simply attributed to the difference in treatment but the difference in results

are due to the effects of random chance. The difference of the means between the 22cm x 22cm and

20cm x 20cm planting densities was significantly more than twice the standard error. Therefore the

differences between the results can be attributed to the difference in treatments.

Replication of the trials was used to minimise the impact of chance and random factors that cant be

controlled on the experiment as averaging the results minimises the impact of these factors on the

results. All three different treatments were replicated three times as well as 63 lettuces in total were

used for each treatment.

Standardisation is keeping all the conditions that can be controlled being kept same except for the

factor being tested. This is so the results can only be attributed to the treatments being tested. The

aspects standardised in the trial are the same amount of replication, the same day that was planted,

the same age the seedlings are, the same area was used, similar raised beds were used for planting,

the same variety of green coral lettuce was used, same amounts of seedlings were planted, the same

planting pattern was used for each bed and all the beds were given the same amount of fertilizer,

pyrethrum spray, watering and snail pellets. However by the end of the trial, some of the lettuce

plants have died but amazingly 2 died for each treatment.

Randomisation was used to eliminate bias from the trial so that the results are valid. The seedlings

were randomly taken out of the tray so each seedling had equal chance of being in a particular

treatment and not just the larger seedlings were used. The spacing allotted to each bed was drawn

out of a hat to ensure all beds had equal chance of having a particular treatment and so that a

treatment was not given a larger bed or any advantage over another.

Areas that the trial could be improved are having more replications, more identical beds as somewere not as wide or long, performing the trial in a different area to ensure that nutrients did not

happen to just be more concentrated at a certain treatment. The exact amount of spray, water and

snail pellets could be kept the consistent for each bed to further ensure that the results can only be

attributed to the treatments.

Conclusion: The hypothesis has been disproven as the control spacing did not provide the heaviest

lettuce crop on average compared to the other treatments. The treatment which did provide the

heaviest lettuce crop on average was the 22cm x 22cm spacing. As shown by the standard error test,

the results of that treatment are due to its difference in spacing. Therefore I recommend that the

standard planting density for green coral lettuce to be 22cm x 22cm. Though the 20cm x 20cmspacing had heavier lettuce on average than the 18cm x 18cm, the results were not significant

enough to ensure it was due to the difference in treatments. Further tests between the 20cm x

20cm and 18cm x 18cm planting densities are needed to clarify which is more beneficial.

Lettuce Crop Trial

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