Articles
THE EFFECT OF MULCHING WITH BLACK PLASTIC ON THE EARLINESS OF THE YIELD OF WATERMELON
Therefore, it is necessary, apart from growing early quality varieties, to use in the production all the effective agrotechnical and other agricultural appliances for intensive growing of watermelons.
In the period 1966–1968, we examined the effect of grafting the kind of melon ‘Mramorna’ on calabash gourd (Lagenaria sp.) under the conditions of Skopje, when the yields were for 45.3% higher than the control (not grafted), and the coefficient of early ripeness of the yields was 52.9%, and for the yield 67.8%. From 1968–1971 examinations were conducted on the appropriateness of the varieties ‘Mramorna’, ‘Stocks 647’ and ‘New Hampshire’ for the early production, and also they were grafted with calabash gourd (Lagenaria sp.). In relation to the control (not grafted ‘Mramorna’), the harvest of the ‘New Hampshire’ started 22 days earlier, of ‘Stocks’ 17 days and of ‘Mramorna’ for 11 days earlier.
The yield was higher in relation to the control i.e. of ‘Stocks’ for 85%, of ‘Mramorna’ 80% and of ‘New Hampshire’ 32%, and the profit was also increased for 56% with the ‘Mramorna’, 109% with the ‘Stocks’ and 48% with the ‘New Hampshire’.
As far as the variety ‘Stocks 647’ is concerned, the examinations proved that this variety is best for its yield, profit and early ripeness, and we wanted to determine the degree of influence of the black plastic over the yield, early ripeness and the commercial effect of this variety grafted with calabash gourd.
The examinations were carried on in 1971 and 1972 under the conditions of Skopje.
The seedlings were produced in hot beds.
The seed was sown on 28 and 29 March, the grafting of the examined variety ‘Stocks 647’ on 7 and 8 April, and the planting on 5 and 6 May.
The grafting was carried out according to the variance of Hristo Georgiev.
The plants were grown according to the scheme 1.5 x 1.5 metres per plant in a hearth.
During the growing an optimal agrotechnique (fertilization, protection, watering, spraying, etc.) was applied.
The investigations were conducted on the following:
- grafted plants, non mulched surface (not covered),
- grafted plants, 50% covered surface, and
- grafted plants, 100% covered surface.
For comparison the customary method of growing was adopted, with sowing of the same variety on 20 April.
For mulching the black PVC plastic sheet 0.1 mm was used.
Thanks to the biological characteristics of Lagenaria sp. which provide for nourishment at a lower temperature of the soil, the grafted plants started to grow fast immediately as they were planted, while those which were mulched the 0.1 mm thick sheet were growing even faster.
So, on 30 May, 1971 the central