Various plastic mulches are widely accessible on the market; however, Indian farmers are
unaware of their efficacy at varying spacings under protected conditions. In order to discover the
effect of mulch and spacing on parthenocarpy cucumber under protected conditions, research
was undertaken at Vegetable Research Farm during the rainy season of the year 2021-22 in Split
Plot Design comprising five levels of mulches, i.e. (M 1 ) double shade plastic mulch, (M 2 ) black
polyethylene mulch, (M 3 ) transparent plastic mulch, (M 4 ) paper mulch and (M 5 ) no mulch and
three plant-to-plant spacing’s i.e. (S 1 ) 30, (S 2 ) 45 and (S 3 ) 60 cm. (M 1 ) Double shade plastic
mulch recorded minimum node at which first flower appears, days to initiation of first flowering,
days to 50% flowering, days to first picking and inter-nodal length whereas the maximum
duration of flowering, fruit length, fruit weight and fruit yield per plant. However, the number of
flowers/plant and number of fruits per plant were recorded significantly higher under (M 2 ) black
polyethylene mulch. Highest benefit: cost ratio was found under (M 4 ) paper mulch. Among
different spacings, 70 × 30 cm recorded statistically maximum number of flowers per plant, fruit
length, fruit yield per plant, fruit yield in Kg per m 2 , minimum days to first picking and
maximum benefit: cost ratio. The interaction of mulch and spacing was non-significant for all the
parameters except for total soluble solids and benefit: cost ratio. Although (M 4 ) paper mulch
exhibited maximum benefit: cost ratio but cucumber crop performed best under the (M 1 ) double
shade plastic mulch followed by (M 2 ) black polyethylene mulch. The main challenge to growing
the parthenocarpic cucumber in polyhouse was higher plant densities which may restrict air
movement and promote humid conditions favorable for disease development and prevent
effective fungicide application. Many researchers studied the effect of spacing on cucumber
production but the reports are contradictory to each other in terms of adopting closer or wider
spacing.