SOME RESPONSES OF CUCUMBERS, GROWN IN BEDS OF PEAT, TO COPPER AND MOLYBDENUM

Cucumbers (cv.
Farbio) were grown in beds of peat under semi-commercial conditions.
Omission of copper from the micronutrients applied to the peat (pH 6.8) severely reduced the early yield and depressed the final yield in the two experiments reported by 56–93%. Fruit size was reduced by 27%. Severe deficiency seriously affected the quality of the fruit; 88% were downgraded for poor development, 10% for poor colour and 33% for poor shape, as compared with 22%, 2% and 23% respectively for plants supplied with copper.
Liming peat from pH 6.2 to 6.8 reduced the yield by 46% when copper was not applied, but had little effect on plants receiving 2.5 g m^-3 copper sulphate.
This rate of application was insufficient, however, and reduced the early and final yields by 83% and 36% respectively.

Omission of molybdenum from the micronutrient dressings applied to the peat (pH 5.1) depressed the yield during the first eight weeks of harvesting by 92% and markedly increased the proportion of poorly developed fruit.
Final yields were depressed by 50–84%. Increasing the pH of peat not supplied with molybdenum from 5.1 to 6.7 resulted in an increase of 200% in the early yield, of 100% in the final yield, and of over 300% in the proportion of good quality fruit during the first eight weeks of harvesting.

XII Working Party on Greenhouse Cucumbers

P. Adams

https://doi.org/10.17660/ActaHortic.1985.156.11